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  • these instructions are periodically updated to include items needed for older/newer versions of Linux. They are marked like this: (SL4.2+) means Scientific Linux 4.2 and newer; (SL4 is equivalent to FC3). (FC5 only) means Fedora Core 5; etc.
  • obsolete items are marked by the "#" sign at the beginning of the line and sometimes have a comment about the reason for removal.
  • typically, we do not "upgrade" machines using the Red Hat "upgrade" function. Instead, we save critical files from the old installation and do a "fresh install" from scratch
  • starting with RHEL7, the recommended OS is CentOS7 (instead of SL7).

Disk configurations

The year is 2019 and SSDs are used exclusively, except for bulk data storage, where one used 6-8-10-12 TB HDDs

For reliability, home directories and data disks must use redundant storage - mdadm raid1 or ZFS raid1/raid6.

For non-critical machines, a single SSD seems to be reliable enough to use as a boot and OS disk. But since any storage device can fail at any time without warning, home directories and data disks should use redundant storage.

Note: for data disks bigger than 4-6TB, mdadm raid1/raid6 is no longer recommended because raid rebuild, verification and repair time has become unreasonably long. Instead, use ZFS raid1/raid6 which implements online verification, repair and disk replacement without requiring machine shutdown or OS down time.

  • single SSD - 120GB min - single partition for "/", no swap partition (create a swap file if swap is needed) - for non-critical machine with no local data storage (OS only)
  • dual SSD - 2x240GB min - all partitions mirrored (RAID1), 30GB "/", rest for /home1 - for daq station with local user home directories and no bulk data storage
  • single SSD + 2x6-8-10-12TB HDD - SSD partition: all "/", HDD partition as ZFS raid1 (mirrored) - for daq station with small local bulk data storage
  • single SSD + 6-8x6-8-10-12TB HDD - for small storage server machines - for daq station with local home directories and large bulk data storage.

For VME processors:

  • network boot - VME-CPU#Network_boot - only option for V7648/V7750, do not use for V7805 (no netboot from GigE), optional for V7865/XVB-602
  • USB boot - 8GB USB for V7805, 16GB USB for V7865/XVB-602


  • save /etc, /var, /root, /opt, (if needed: /usr/local, /tftpboot) by rsync to some data disk (/ladd/data0/root)
  • check that "/" partition (it will be overwritten) is different from /home1 and /data partitions
  • note the MAC addresses of all network interfaces, add them to ladd00 dhcpd.conf to enable PXE boot into the SL "network installer"
  • shutdown

Running installer (CentOS7)

CentOS7 can be installed from vanilla CentOS7 installation media or from a custom USB key build per there instructions:

The custom installer makes it easy to use a custom kickstart file (ks.cfg).

Instructions for using the usb-installer:

  • disconnect machine from network
  • plug the usb-installer into a usb3 port (blue colour)
  • reboot machine, select booting from usb (press F8 on ASUS motherboards)
  • usb-installer boot menu offers to install CentOS7, go there
  • CentOS7 should boot (many messages scroll on screen)
  • into graphical mode
  • into installer main menu
  • all installer options should "happy" except for the "installation destination"
  • go to the "installation destination" menu
    • unselect all disks except for the SSD where the OS will be installed
    • (MOST IMPORTANT: unselect the USB installer disk!)
    • select "I will configure..."
    • say "done"
    • the "manual partitionning" menu will open
      • use the "-" button to delete all existing partitions
      • select "standard partition"
      • click on the "+" button
      • in the "Add new partition" dialog, set mount point "/", capacity blank, click "add mount point"
      • check capacity (should be full size of SSD), check filesystem type (should be XFS)
      • say "done", there will be a warning about absent swap partition, say "done" again.
      • in the big useless dialog, say "accept changes"
      • should be back to the "installation summary" screen, "installation destination" should be happy now
  • after everything is happy, say "begin installation"
  • as the installation proceeds, set the password for the root user
  • after installation is complete, reboot the machine
  • unplug the usb-installer, CentOS7 should boot from SSD into the login screen
  • click on "not listed?", login as root
  • setup network connection:
    • open a terminal
    • start "nm-connection-editor"
    • click on "+" to create a new connection profile
    • select "wired ethernet"
    • select "add profile..."
    • in "Identity", set "name" to "static"
    • in "Identity", check that "Connect automatically" and "Make available..." is enabled
    • in "IPv4", set "Addresses" to "manual" instead of "dhcp"
    • enter IP address, netmask, gateway, dns, search
    • say "Add", then close/quit the network settings
  • connect network cable
  • network should be up, ping ladd00 should work
  • run: yum update -y
  • check new kernel is installed: ls -l /boot
  • logout and restart (good luck finding these buttons in the gui!)
  • confirm correct linux kernel is selected during boot (-229.20, not the original installer kernel)
  • login as root, confirm network is up, proceed with the rest of these instructions

Configure SSH


  • Login from the console
  • restore the SSH keys from backup (/etc/ssh/*key*)
  • service sshd restart
  • ssh into the new machine as root
  • ssh root@localhost, ctrl-C
  • ### this is done later from Konstantin's git repository - scp root@ladd00:/root/authorized_keys ~root/.ssh/
  • (not needed for SL5.5 kickstart) check that /etc/ssh/ssh_config contains "ForwardX11 yes" and "ForwardX11Trusted yes":
echo "  ForwardX11 yes" >> /etc/ssh/ssh_config
echo "  ForwardX11Trusted yes" >> /etc/ssh/ssh_config

Set hostname

Set hostname: (use full name, i.e.

emacs -nw /etc/hostname

Configure email

  • TRIUMF: use relayhost =
  • CERN: use relayhost =
  • edit /etc/postfix/, set "relayhost ="
  • echo "" >> ~root/.forward

Make log files readable

chmod a+r /var/log/messages
chmod a+r /var/log/yum.log

Activate /etc/rc.local

Activate rc.local:

chmod a+x /etc/rc.local
chmod a+x /etc/rc.d/rc.local  # TL edit
systemctl enable rc-local
systemctl start rc-local
systemctl status rc-local

Disable "persistent network names" (DO NOT DO THIS)

/bin/touch /etc/udev/rules.d/75-persistent-net-generator.rules
/bin/rm /etc/udev/rules.d/70-persistent-net.rules
#shutdown -r now

Configure NIS client (CentOS7)

yum -y install ypbind authconfig
echo "NISTIMEOUT=5" >> /etc/sysconfig/network
echo "NETWORKWAIT=yes" >> /etc/sysconfig/network
authconfig --enablenis --enablepreferdns --nisdomain LADD-NIS --nisserver --update
ypcat -k passwd
systemctl restart autofs
  • On the master NIS node (ladd00), add this new node to /etc/netgroup, and update NIS maps (cd /var/yp; make)
  • Use "system-config-users" to add local user accounts
  • enable selinux ssh key login to nfs mounted home directories:
setsebool -P use_nfs_home_dirs 1

Configure NIS client (CentOS8)

  • all the same as for CentOS7
  • ensure correct boot order for ypbind (in CentOS 8.1 ypbind is started before network is ready, service file uses "Wants" instead of "After")
mkdir /etc/systemd/system/ypbind.service.d
echo -e "[Unit]\\n" > /etc/systemd/system/ypbind.service.d/local.conf
systemctl daemon-reload
systemctl cat ypbind.service

Configure NIS secondary server (CentOS7)

Enable local NIS server, make local machine use it:

yum -y install ypserv
/usr/lib64/yp/ypinit -s ladd00 ### (/usr/lib/yp/ypinit on 32-bit machines)
### ypinit will give lots of errors about "rpc.ypxfrd failed: RPC: Can't decode result"; can be ignored
systemctl disable ypxfrd yppasswdd
systemctl stop ypxfrd yppasswdd
systemctl enable rpcbind ypserv
systemctl start rpcbind ypserv
emacs -nw /etc/yp.conf # change "domain XXX server" to read "domain XXX server localhost"
systemctl restart ypbind
ypwhich # should say "localhost"
ypcat -k auto.master # should work

Punch hole in the firewall: (or "make" on NIS master will complain)

echo YPSERV_ARGS=\"-p 800\" >> /etc/sysconfig/network
systemctl restart ypserv
firewall-cmd --get-services
firewall-cmd --add-service rpc-bind --permanent
firewall-cmd --add-port=800/tcp --add-port=800/udp --permanent
firewall-cmd --reload
firewall-cmd --list-all
  • on the NIS master:
    • add the new machine to /var/yp/ypservers, run "make -C /var/yp" and also "cd /var/yp; yppush -h newmachine ypservers"
      • TL (2020-09): we not doing this anymore? I guess it doesn't work anyway...
    • if using /var/yp/securenets, copy it from NIS master to new NIS secondary server

Enable hourly NIS update cron job (DO THIS AFTER git pull scripts, see below)

cd ~/git/scripts
git pull
cd etc
cd ~/git/scripts/etc; ln -s $PWD/ypxfr-cron-hourly /etc/cron.hourly

Configure AUTOFS (CentOS7)

yum -y install autofs
systemctl enable autofs
systemctl start autofs
ls -l /daq/daqshare

Label Selinux labels

When upgrading non-selinux machines (el6) to el7 (selinux enforcing) the existing user home directories will not have the correct selinux labels and many things will not work, including ssh logins (sshd cannot access ~user/.ssh files).

semanage fcontext -a -e /home /home1 ### selinux has special rules for /home, assign them to /home1
restorecon -R -v /home1 ### apply the new rules to files in /home1
ls -Zd /home1/alpha/.ssh
# should say: drwx------. alpha users system_u:object_r:ssh_home_t:s0  /home1/alpha/.ssh

Configure time (CentOS7)

Time server ntpd was replaced by chronyd.

yum -y install chrony
echo server time1 iburst >> /etc/chrony.conf
echo server time2 iburst >> /etc/chrony.conf
echo server time3 iburst >> /etc/chrony.conf
systemctl enable chronyd
systemctl restart chronyd
chronyc sources
chronyc tracking
  • if desired, edit /etc/chrony.conf, remove non-triumf time servers

Enable automatic system updates (CentOS7)

Disable yum-cron:

rpm --erase yum-cron
/bin/rm -v /var/lock/subsys/yum-cron
/bin/rm -v /etc/cron.daily/0yum-daily.cron
/bin/rm -v /etc/cron.hourly/0yum-hourly.cron

Enable yum-autoupdate:

yum install -y epel-release
yum install -y yum-changelog yum-protectbase yum-tsflags yum-versionlock
rpm -vh --install
rpm -vh --install
#rpm -vh --install
systemctl enable yum-autoupdate
systemctl start yum-autoupdate
systemctl status yum-autoupdate

Disable automatic system updates (CentOS7)

yum -y erase yum-autoupdate
/bin/rm -f /etc/sysconfig/yum-autoupdate.rpmsave
/bin/rm -f /var/lock/subsys/yum-autoupdate

Enable automatic system updates (CentOS8)

yum -y install dnf-automatic
systemctl enable --now dnf-automatic.timer
systemctl list-timers *dnf-*

edit /etc/dnf/automatic.conf

apply_updates = yes

Configure system services (CentOS7)

  • systemctl list-unit-files | grep enabled | sort ### (to see enabled services)
  • disable unwanted services:
systemctl disable bluetooth
systemctl disable dm-event
systemctl disable dmraid-activation
systemctl disable iscsid
systemctl disable iscsi
systemctl disable iscsiuio
systemctl disable libvirtd
systemctl disable lvm2-lmetad
systemctl disable lvm2-monitor
systemctl disable ModemManager
systemctl disable multipathd
systemctl disable netcf-transaction
systemctl disable lvm2-lvmetad.socket
systemctl disable lvm2-lvmpolld.socket
systemctl disable iscsid.socket
systemctl disable iscsiuio.socket
systemctl disable ksm
systemctl disable ksmtuned
#systemctl disable 

Erase unwanted packages (CentOS7)

  • PackageKit # bugs users about security updates, hogs yum lock
  • perl-homedir # creates unwanted $HOME/perl5
  • ModemManager # thinks that all USB-attached devices are modems
  • pcp # sends error email to itself, does not work
  • abrt # sends email to root about useless crashes, i.e. crash of X when machine is rebooted
  • rear # some kind of backup and recovery tool, not clear what it does, but it sends email complaining how it is broken
  • bash-completion # "echo $HOME/<TAB>" becomes "echo \$HOME" (notice "\" added before "$") preventing tab-completion from doing anything useful.
yum -y erase PackageKit perl-homedir ModemManager pcp abrt abrt-libs abrt-gui-libs rear bash-completion

Disable unwanted package "tracker"

The "tracker" package is part of the GNOME desktop, it scans the content of all files into a database for quick searching.

When it malfunctions, bad things happen, i.e. read through

Specific problem I see is that it floods the system log with error messages. Also consumes network and filesystem bandwidth for NFS mounted home directories.

This package cannot be removed by "yum erase tracker" dues to dependencies from core GNOME desktop.

Instead, do this to deactivate it:

chmod -x /usr/libexec/tracker-*
chmod -x /usr/bin/tracker
chattr +i /usr/bin/tracker
chattr +i /usr/libexec/tracker-*

Configure external package repositories (CentOS7)

EPEL: (addtional packages)

yum install epel-release

ELREPO: (kernel modules and drivers) (CentOS8)

yum install elrepo-release

ELREPO: (kernel drivers)

rpm --import
rpm -Uvh
yum -y install yum-plugin-fastestmirror

Install packages needed to continue with installation


(these packages are sometimes missing, they are needed to follow following instructions instructions)

(SL6.5: libotf is a dependancy of emacs - SL6.5 installer fails to install it)

yum install ed patch wget git libotf gdisk emacs perl

Configure Konstantin's scripts


mkdir ~root/git
cd ~root/git
git clone
cd scripts
git pull

Go back to the NIS slave server and install the hourly NIS update cron job.

Enable yum version lock

yum install yum-plugin-versionlock
#yum versionlock packagename # yum versionlock rpcbind
#yum versionlock list # list locked packages
#yum versionlock delete packagename # unlock given package
#yum versionlock clear # delete all locks

Configure trusted ssh keys


ssh localhost
interrupt by Ctrl-C
/bin/cp ~/git/scripts/etc/authorized_keys ~/.ssh/

Configure hardware sensors

  • yum -y install lm_sensors
  • sensors-detect (accept default answer to all questions - press ENTER)
  • systemctl restart lm_sensors
  • sensors (to see available sensors)

If no sensors are detected by standard drivers, follow motherboard-specific instructions at the bottom of this page.

Configure IPMI sensors

Some machines support the IPMI interface for monitoring the hardware: fan speeds, temperatures, voltages.

  • find out if IPMI is supported. Try this:
dmidecode | grep -i ipmi

if output is not blank, IPMI is maybe supported.

  • install and enable IPMI software:
yum install "OpenIPMI*" ipmitool
service ipmi start
ipmitool sensor ### to confirm IPMI is present. If output is blank, do not go further.
chkconfig ipmi on
chkconfig ipmievd on
service ipmi restart
service ipmievd restart
tail -100 /var/log/messages ### look at messages logged by ipmievd
  • (CentOS7) install and enable IPMI software:
yum install "OpenIPMI*" ipmitool
systemctl start ipmi
ipmitool sensor ### to confirm IPMI is present. If output is blank, do not go further.
systemctl list-unit-files | grep -i ipmi
systemctl enable ipmi
systemctl restart ipmi
systemctl status ipmi
systemctl enable ipmievd
systemctl restart ipmievd
systemctl status ipmievd
tail -100 /var/log/messages ### look at messages logged by ipmievd
  • if ipmievd complains about SEL buffer overflow, clear it manually:
ipmitool sel list ### show ipmi messages in raw format
ipmitool sel elist ### show ipmi messages in useful format
ipmitool sel elist > file ### save ipmi messages into a file
ipmitool sel clear  ### clear all accumulated ipmi messages
  • useful ipmi commands:
    • ipmitool sensor -- read hardware sensors
    • ipmitool sel elist -- report all accumulated messages

Configure ECC memory

  • check that machine has ECC memory: dmidecode --type memory | grep -i ecc

Configure mcelog (machine check exception)

  • yum install mcelog
  • check that mcelog is running: ps -efw | grep mcelog
  • (el6) chkconfig mcelogd on; service mcelogd restart
  • (el7) systemctl status mcelog.service; systemctl enable mcelog.service; systemctl restart mcelog.service

Check for MCE (machine check exception) messages:

  • mcelog --client
  • grep -i mce /var/log/messages*
  • grep -i ecc /var/log/messages*

Configure EDAC

yum install edac-utils
edac-ctl --mainboard
edac-ctl --status
lsmod | grep edac
modprobe ie31200_edac ### driver for Intel E3-1200 series ECC memory

[root@grsmid00 ~]# ls -l /sys/devices/system/edac/mc/
... empty

[root@alpha00 ~]# ls -l /sys/devices/system/edac/mc/
drwxr-xr-x. 15 root root    0 Oct 25 16:40 mc0
[root@alpha00 ~]# ls -l /sys/devices/system/edac/mc/mc0
total 0
-r--r--r--. 1 root root 4096 Oct 25 16:40 ce_count
-r--r--r--. 1 root root 4096 Oct 25 16:40 ce_noinfo_count
drwxr-xr-x. 3 root root    0 Oct 25 16:40 csrow0
drwxr-xr-x. 3 root root    0 Oct 25 16:40 csrow1
drwxr-xr-x. 3 root root    0 Oct 25 16:40 csrow2
drwxr-xr-x. 3 root root    0 Oct 25 16:40 csrow3
-r--r--r--. 1 root root 4096 Oct 25 16:40 max_location
-r--r--r--. 1 root root 4096 Oct 25 16:40 mc_name
drwxr-xr-x. 2 root root    0 Oct 25 16:40 power
drwxr-xr-x. 3 root root    0 Oct 25 16:40 rank0
drwxr-xr-x. 3 root root    0 Oct 25 16:40 rank1
drwxr-xr-x. 3 root root    0 Oct 25 16:40 rank2
drwxr-xr-x. 3 root root    0 Oct 25 16:40 rank3
drwxr-xr-x. 3 root root    0 Oct 25 16:40 rank4
drwxr-xr-x. 3 root root    0 Oct 25 16:40 rank5
drwxr-xr-x. 3 root root    0 Oct 25 16:40 rank6
drwxr-xr-x. 3 root root    0 Oct 25 16:40 rank7
--w-------. 1 root root 4096 Oct 25 16:40 reset_counters
-r--r--r--. 1 root root 4096 Oct 25 16:40 seconds_since_reset
-r--r--r--. 1 root root 4096 Oct 25 16:40 size_mb
lrwxrwxrwx. 1 root root    0 Oct  2 12:02 subsystem -> ../../../../../bus/mc0
-r--r--r--. 1 root root 4096 Oct 25 16:40 ue_count
-r--r--r--. 1 root root 4096 Oct 25 16:40 ue_noinfo_count
-rw-r--r--. 1 root root 4096 Oct 25 16:40 uevent
[root@alpha00 ~]# 

[root@alpha00 ~]# edac-ctl --status
edac-ctl: drivers are loaded.

[root@alpha00 ~]# edac-util 
edac-util: No errors to report.

[root@alpha00 ~]# edac-util -s
edac-util: EDAC drivers are loaded. 1 MC detected

Configure SMARTD (CentOS7)

Default el7 smartd config files send deficient email notices about disk failures. Overwrite.

/bin/cp ~/git/scripts/etc/smartd.conf /etc/smartmontools/
/bin/cp ~/git/scripts/etc/ /etc/smartmontools/
systemctl enable smartd
systemctl restart smartd
systemctl status smartd

Enable User Disk Quotas (OPTIONAL)


[root@isdaq00 home1]# grep quota /etc/fstab
UUID=5a2aefbd-45db-475e-841e-12ec89220fbd /home1 ext4 defaults,grpquota,usrquota 1 2
  • cd /; umount /home1; mount /home1
  • quotacheck -cug /home1
  • quotacheck -avug
  • quotaon -av
  • quota system is now active
  • increase the soft quota time limit from default 7days to 30 or 60 days: edquota -t
  • set quotas for all users (see below)
  • setup warnquota:
    • create warnquota config file: emacs -nw /etc/warnquota.conf
# values can be quoted:
MAIL_CMD        = "/usr/sbin/sendmail -t"
FROM            = root
SUBJECT         = User %i@%h exceeded allocated disk quota
CC_TO           = "root"
# If you set this variable CC will be used only when user has less than
# specified grace time left (examples of possible times: 5 seconds, 1 minute,
# 12 hours, 5 days)
# CC_BEFORE = 2 days
SUPPORT         = "root"
# Text in the beginning of the mail (if not specified, default text is used)
# This way text can be split to more lines
# Line breaks are done by '|' character
# The expressions %i, %h, %d, and %% are substituted for user/group name,
# host name, domain name, and '%' respectively. For backward compatibility
# %s behaves as %i but is deprecated.
MESSAGE         = User "%i" on "%h" has exceeded the allocated disk quota.||Please delete any unnecessary files on following filesystems or|contact the system administrato
r to increase your quota allocation:|
SIGNATURE       = --|automated email from warnquota
    • note that %i@%h in the SUBJECT line do not seem to work
    • create cron job: emacs -nw /etc/cron.daily/warnquota
    • chmod a+x /etc/cron.daily/warnquota
    • touch /etc/crontab

Useful commands for managing quotas:

  • repquota -a | sort -n -k3 ### show quota of all users sorted by disk usage
  • edquota -u username ### open "vi" editor to change user quotas
  • repquote -a | grep username ### report quota for given user
  • setquota -u username 0 0 0 0 /home1 ### disable quotas for given user
  • setquota -u username 50000000 100000000 0 0 /home1 ### set quotas for 50GB soft and 100GB hard
  • edquota -t ### change user quota time limits
  • edquote -tg ### change group quota time limits

Enable NFS V4 server (CentOS7)

  • create /etc/exports. example: (fsid numbers should be unique and increase 1,2,3,...)
/home1  @home_export(rw,no_root_squash,async,fsid=1)
/data1  @data_export(rw,no_root_squash,async,fsid=2)
  • check the netgroup file
    • if using NIS: check NIS netgroup: ypcat -k netgroup
    • if no NIS, create /etc/netgroup: @daqmachines (deap00,,) (deap01,,) (deap02,,)
    • if no NIS, edit /etc/nsswitch.conf, make the netgrooup line read: "netgroup: files"
  • enable things, start them:
firewall-cmd --get-services
firewall-cmd --permanent --add-service=nfs
firewall-cmd --permanent --add-service=rpc-bind ### needed for ubuntu automounter
firewall-cmd --reload
firewall-cmd --list-all
systemctl enable nfs-server
systemctl start nfs-server
systemctl status nfs

Enable NFS V3 server (CentOS7)

ps -efw | grep rpc.mountd # should be running!
firewall-cmd --get-services
firewall-cmd --permanent --add-service=mountd
firewall-cmd --permanent --add-service=rpc-bind
firewall-cmd --reload
firewall-cmd --list-all

Enable NFS V3 server

  • edit /etc/hosts.allow, add or uncomment "mountd:"
  • create /etc/exports. example:
/home1  @home_export(rw,no_root_squash,async)
/data1  @data_export(rw,no_root_squash,async)
  • check the netgroup file
    • if using NIS: check NIS netgroup: ypcat -k netgroup
    • if no NIS, create /etc/netgroup: @daqmachines (deap00,,) (deap01,,) (deap02,,)
    • if no NIS, edit /etc/nsswitch.conf, make the netgrooup line read: "netgroup: files"
  • chkconfig nfs on
  • chkconfig nfslock on
  • service nfs restart

Then on ladd00 need to do

  • ssh to root@ladd00
  • edit /etc/auto.daq to add new machine...
  • make -C /var/yp

Enable NFS V4 SERVER (SL6)

  • if used with NIS, same as NFSv3
  • if used as standalone, need to edit idmapd.conf - set the "Domain" name to the same value on NFS server and NFS slave (default automagically determined value does not always work). More TBW.

Enable AMANDA backups

AMANDA backups are already enabled by TRIUMF kickstart installs. For non-kickstart installation, follow instructions at [http://amanda/~amanda], or look at "/triumfcs/trshare/olchansk/linux/amanda/amanda-enable.perl". As final step, use [] to contact TRIUMF CS to add this new machine to the amanda backup list.

  • yum install triumf-amanda

Enable AMANDA backups (CentOS7)

yum install amanda-client
systemctl list-unit-files | grep -i amanda
#systemctl enable amanda
systemctl enable amanda.socket
systemctl enable amanda-udp.socket
systemctl restart amanda.socket
systemctl restart amanda-udp.socket
firewall-cmd --get-services
firewall-cmd --permanent --add-service=amanda-client
firewall-cmd --reload
firewall-cmd --list-all
echo amanda amdump >> /var/lib/amanda/.amandahosts

On amanda server, add new machine to the disklist, then:

amcheck -c daily titan00


DAQ dcache server is mounted as


For Centos-7 machines, you need to adjust the firewall rules in order to be able to communicate with the trdata machines; this is only necessary if you are copying data to trdata. The firewall changes are

firewall-cmd --permanent --add-rich-rule="rule family="ipv4" source address="" port protocol="tcp" port="0-65535" accept"
firewall-cmd --permanent --add-rich-rule="rule family="ipv4" source address="" port protocol="tcp" port="0-65535" accept"
firewall-cmd --permanent --add-rich-rule="rule family="ipv4" source address="" port protocol="tcp" port="0-65535" accept"
firewall-cmd --reload
firewall-cmd --list-all

This instructions are unnecessary

  • # mkdir -p /pnfs
  • # edit /etc/rc.local, add to the end of file: "mount -o intr,rw,noac,hard,nfsvers=3 trdata00:/pnfs /pnfs &"
  • # . /etc/rc.local

For more information on, see TrdataDcache dcache page.

Configure Ganglia (Centos7)

CentOS7 Ganglia instructions (EPEL7 ganglia-3.7.2)

/bin/rm /etc/gmond.conf
yum -y install "ganglia-gmond*"
/bin/cp -v /dev/null /etc/ganglia/conf.d/multicpu.conf   # collects useless data
/bin/cp -v /dev/null /etc/ganglia/conf.d/netstats.pyconf # spews errors into syslog
/bin/cp -v /dev/null /etc/ganglia/conf.d/diskstat.pyconf # collects useless data
/bin/cp -v /dev/null /etc/ganglia/conf.d/procstat.pyconf # do not create /tmp/gmond.conf
yum erase -y ganglia-vmstat ganglia-sensors ganglia-top ganglia-smart ganglia-cpumhz
cd ~/git/scripts
git pull
/bin/cp etc/gmond.conf /etc/ganglia/gmond.conf
systemctl enable gmond
systemctl restart gmond
systemctl status gmond
cd ganglia
make install
cd ~

Configure Ganglia (Centos8)

CentOS8 Ganglia instructions (EPEL8 ganglia-3.7.2)

/bin/rm /etc/gmond.conf
yum -y install "ganglia-gmond*"
/bin/cp ~/git/scripts/etc/gmond.conf /etc/ganglia/gmond.conf
systemctl enable gmond
systemctl restart gmond
systemctl status gmond
cd ~/git/scripts/ganglia
git pull
make install

Configure TRIUMF DAQ packages


cd /etc/yum.repos.d

Install Konstantin's packages


yum --disablerepo=\* --enablerepo=triumf-daq --skip-broken install diskscrub emailonreboot monitor_nfs

Install memtest and PXE boot


cd /boot

emacs -nw /boot/grub/grub.conf
title memtest86+-5.01
      root (hd0,0)
      kernel /boot/memtest86+-5.01.bin.gz
title memtest86+-4.20
      root (hd0,0)
      kernel /boot/memtest86+-4.20.bin.gz
title memtest86+-4.10
      root (hd0,0)
      kernel /boot/memtest86+-4.10
title pxeboot
      root (hd0,0)
      kernel /boot/gpxe-1.0.1+-gpxe.lkrn

Install node monitoring



yum --disablerepo=\* --enablerepo=triumf-daq --skip-broken install triumf_nodeinfo
/usr/sbin/sendnodeinfo.perl --config
emacs -nw /etc/nodeinfo

Install gonodeinfo node monitoring

(+Ubuntu, +CentOS7, +CentOS8)

go to follow instructions:

yum -y install golang
mkdir ~/git
cd ~/git
git clone
# or git clone
cd gonodeinfo
git pull
make install # install gonodeinfo agent
cd ~ # this is important
  • emacs -nw /etc/gonodeinfo.conf
  • change "Description", "Location", "User" and "Administrator" as appropriate (or delete them)
  • change "Servers" to read: Servers:
  • run gonodeinfo -e
  • if error is "connection refused". go to the nodeinfo server to add this client to the access control list:
  • on the gonodeinfo server: run /opt/gonodeinfo/gonodereceive.exe -a daq13
  • try gonodeinfo again, there should be no error
  • on the gonodeinfo server: run gonodereport, look at the web pages, the new machine should be listed now

Install latest system updates


yum update -y

Configure TRIUMF Printers (CentOS7)

systemctl stop cups
systemctl disable cups
echo "ServerName" > /etc/cups/client.conf
lpstat -a

Disable syslog spam (CentOS7)

Default el7 config is spamming the syslog with useless messages "systemd: Starting Session", etc. Disable this:

echo auditctl -e 0 >> /etc/rc.local
echo /usr/bin/systemd-analyze set-log-level notice >> /etc/rc.local

Install basic system packages (CentOS7)

(if starting from minimal system, basic system packages required:)

yum install -y which psmisc redhat-lsb-core xorg-x11-xauth xterm emacs-nox rsync tcpdump strace nfs-utils sysstat iftop tcsh
yum install -y gcc gcc-c++ gdb glibc-static libstdc++-static zlib zlib-devel openssl-devel httpd-tools

Install packages needed for QUARTUS, ROOT, EPICS and MIDAS DAQ


yum install --skip-broken giflib.x86_64 sysstat "libusb-devel*" "libusbx-devel*" unixODBC-devel postgresql-devel libxml2-devel libXpm-devel libgfortran git compat-readline43 "graphviz*" dcap "tigervnc*" telnet glibc"*" strace "fftw*" libpng "freetype*" xpdf "xemacs*" tkcvs xterm mutt "*-g77*" joe "libXmu*" dcap-devel gsl-devel pcre-devel h5py gd-devel xorg-x11-fonts"*" minicom xfig"*" perl-BSD-Resource "net-snmp-*" readline-static git-all nasm imake tcl-devel gv xorg-x11-twm expat-devel screen compat-readline5 ImageMagick ImageMagick-devel wget alacarte scipy numpy sympy nedit gnuplot php-cli php-domxml-php4-php5 php-gd php-fpdf php-cli kdebase cmake tcpdump sqlite sqlite-devel kdegraphics gdisk lsof gconf-editor iftop tk-devel mcelog kdm blt itcl lz4 bzip2 pbzip2 apr-devel apr-util-devel net-tools golang"*" --exclude golang-cover"*"hg"*" --exclude golang"*"hg"*" --exclude golang-pkg"*" --exclude golang-github"*" --exclude golang"*"git"*" mesa"*" xerces-c"*" diffuse clang i2c-tools texlive-revtex texlive-revtex4 kile kbibtex xrdp glibc.i686 gimp gimp-data-extras perl-GD"*" perl-Math"*" perl-Statistics-Basic cmake3 cmake3-gui extra-cmake-modules python2-pip mariadb-devel glibc-devel.i686 libzstd zlib-devel.i686

Install optional packages


(do not install boost on 32-bit machines)

yum install --skip-broken "boost-*"

(packages for 32-bit software compilation on 64-bit machines. this is optional)

yum install --skip-broken giflib.i386 giflib.i686 compat-libf2c-34.i386 compat-libf2c-34.i686 mysql-devel.i686 openssl-devel.i686 unixODBC-devel.i686 libstdc++-devel.i386 libstdc++-devel.i686 "zlib-*.i686" "libXext-*.i686" "libXtst-*.i686" glibc-static.i686 freetype.i686 fontconfig.i686 libpng.i686 libXrender.i686 glibc-devel.i686 libX11-devel.i686 libXpm-devel.i686 libXft-devel.i686 mysql-devel.i686 dcap-devel.i686 gsl-devel.i686 pcre-devel.i686 fontconfig-devel.i686 freetype-devel.i686 libpng-devel.i686 libjpeg-devel.i686 libgfortran.i686 libxml2-devel.i686 gd-devel.i686 readline-devel.i686 ncurses-devel.i686 libXdmcp.i686 readline-static.i686 compat-readline5.i686

yum install boost-devel.i686

(separately install these packages - they collide with the big bunch above)

yum install rdesktop

yum reinstall urw-fonts

Install libraries for PHYSICA (CentOS7)

To run physica built on el6 from git sources on el7, do this:

(building physica on el7 is nort supported at this time)

(see more

yum -y install libX11.i686 gd.i686 libpng12.i686 readline.i686 compat-libf2c-34.i686

Install additional desktop environements (CentOS7)

# LXQT (from EPEL)
# NOT COMPATIBLE WITH el7.7 # yum -y install "lxqt*"
# Cinnamon desktop (from EPEL)
yum -y install cinnamon
# KDE5 not available yet
# MATE (from epel)
yum -y groupinstall "MATE Desktop"
yum -y install mate-common mate-icon-theme-faenza mate-netspeed mate-sensors-applet mate-themes-extras mate-utils
yum -y erase ModemManager abrt abrt-libs abrt-gui-libs
# XFCE4 (from EPEL)
yum -y groupinstall xfce
yum -y install "xfce*plugin" xfce4-about --exclude xfce4-hamster-plugin
yum -y erase bash-completion
  • make the MATE desktop as default
cd ~root/git/scripts/
git pull
/bin/cp -v etc/lightdm_default_mate.conf /etc/lightdm/lightdm.conf.d/
  • lighdm login manager (from EPEL)
yum install lightdm lightdm-kde lightdm-qt lightdm-qt5
  • and switch from gdm to lighdm
systemctl disable gdm.service
systemctl enable lightdm.service
(systemctl stop gdm; systemctl restart lightdm) &

Install SMART scripts


ln -sf ~/git/scripts/smart-status/smart-status.perl ~/

Install NTFS drivers

yum install ntfs-3g ntfsprogs (from EPEL)

Install HFS and HFS+ drivers (CentOS7)

yum --disablerepo=\* --enablerepo=elrepo install kmod-hfs kmod-hfsplus

Install Google Chrome web browser (64-bit CentOS7)

DOES NOT WORK AS OF google-chrome-stable-114 because google uses signature incompatible with CentOS-7, see

automatic updates will fail with signature check error, to defeat it lock old version of google-chrome:

yum versionlock google-chrome-stable


/bin/cp ~/git/scripts/etc/google-chrome-64.repo /etc/yum.repos.d/
yum install google-chrome-stable

Enable monitoring of HTTPS certificates

On SL6, CentOS7:

yum install crypto-utils
strace -f /etc/cron.daily/certwatch  |& grep open  | grep crt

Enable 100dpi fonts for EPICS


ln -s /usr/share/X11/fonts/100dpi /etc/X11/fontpath.d/

Enable crontab @reboot for MIDAS (CentOS7)

el7 has a bug - cron @reboot entries for normal users can run before autofs is ready, so if the home directory is on autofs/NFS, it cannot be accessed and the cron job fails. If MIDAS is supposed to be started by cron @reboot, it will not start (there *will* be an error message in /var/log/cron).

mkdir /etc/systemd/system/crond.service.d
echo -e "[Unit]\nAfter=ypbind.service autofs.service\n" > /etc/systemd/system/crond.service.d/local.conf
systemctl daemon-reload
systemctl cat crond.service

el7 has a second bug, sometimes it thinks the network is running when it is not, specifically, DNS is not working and autofs mount of user home directory fails. So not only cron has to wait for ypbind and autofs to be ready, we also have to wait for DNS to be ready:

cd ~/git/scripts
git pull
cp etc/wait-for-dns.service /etc/systemd/system/
systemctl daemon-reload
systemctl enable wait-for-dns
systemctl restart wait-for-dns # should return immediately. if there is a 30 second time, script is broken, disable it
systemctl status wait-for-dns # to see what went wrong.

Explore the systemd dependacy tree using "systemctl list-dependencies" maybe with "--all".

Visualize the exact boot sequence from previous boot: "systemd-analyze plot > xxx.svg", look at the svg file using a web browser.

Enable firewall for MIDAS (CentOS7)

Default el7 configuration prevents all access to servers running on the local machine, including access to MIDAS mhttpd (tcp port 8443) and mserver (all tcp ports).

To enable access to mhttpd:

firewall-cmd --add-port=8443/tcp --permanent
firewall-cmd --reload
firewall-cmd --list-all

To enable access to the mserver from a specific host: (replace with the IP address of the permitted host)

firewall-cmd --permanent --add-rich-rule="rule family="ipv4" source address="" port protocol="tcp" port="0-65535" accept"
firewall-cmd --reload
firewall-cmd --list-all

To enable access from the private network (replace "" with your private network number):

firewall-cmd --permanent --add-rich-rule="rule family="ipv4" source address="" port protocol="tcp" port="0-65535" accept"
firewall-cmd --reload
firewall-cmd --list-all

Enable firewall for EPICS (CentOS7)

To enable access to TRIUMF EPICS servers, do this:

firewall-cmd --permanent --add-rich-rule="rule family="ipv4" source address="" accept"
firewall-cmd --reload
firewall-cmd --list-all

For UCN the controls people seem to have EPICS setup on a different server; this might be true for CMMS as well. In this case the firewall rule change should be

firewall-cmd --permanent --add-rich-rule="rule family="ipv4" source address="" accept"
firewall-cmd --reload
firewall-cmd --list-all

Disable gdm and X11 (OPTIONAL)

initctl stop prefdm
echo "start on never" > /etc/init/prefdm.override
echo "start on never" > /etc/init/splash-manager.override
initctl reload-configuration

then enable login on default console:

echo "plymouth quit" >> /etc/rc.local
echo "X_TTY=xxx/dev/tty1" >> /etc/sysconfig/init


  • to run Java "web start" jnlp files (EVO, SEEVOGH, etc): javaws Downloads/spider.jnlp
  • install javaws:
  • yum install icedtea-web icedtea-web-javadoc

Install firefox java plugin (OPTIONAL, DO NOT DO THIS)

This installs the Oracle Java plugin:

  • rpm -vh --install ~deap/jdk-7u15-linux-x64.rpm
  • ls -l /usr/lib64/mozilla/plugins/
  • ln -s /usr/java/jdk1.7.0_15/jre/lib/amd64/ /usr/lib64/mozilla/plugins/
  • start firefox, go edit->preferences->general->manage add-ons->plugins
  • "java plugin 1.7.0_15" should be listed

Configure USB device permissions


Configure USB device permissions for user access to USB-serial devices, Altera USB Blaster, etc.

  • create file /etc/udev/rules.d/99-usb-chmod.rules with this contents:
emacs -nw /etc/udev/rules.d/99-usb-chmod.rules
ACTION=="add", SUBSYSTEM=="usbmisc", RUN+="/bin/chmod a+wr $env{DEVNAME}" 
ACTION=="add", SUBSYSTEM=="usb_device", RUN+="/bin/chmod a+wr /dev/%c"
ACTION=="add", SUBSYSTEM=="usb_device", RUN+="/bin/chmod a+wr /proc/%c"
ACTION=="add", ENV{DEVTYPE}=="usb_device", RUN+="/bin/chmod a+wr $env{DEVNAME}"
ACTION=="add", ENV{DEVTYPE}=="usb_device", RUN+="/bin/chmod a+wr $env{DEVICE}"
ACTION=="add", ENV{PHYSDEVBUS}=="usb-serial", RUN+="/bin/chmod a+wr $env{DEVNAME}"
ACTION=="add", ENV{DEVPATH}=="/class/tty/ttyS*", RUN+="/bin/chmod a+wr $env{DEVNAME}"
ACTION=="add", SUBSYSTEM=="tty", DEVPATH=="*ttyUSB*", RUN+="/bin/chmod a+rw $env{DEVNAME}"
ACTION=="add", SUBSYSTEM=="tty", DEVPATH=="*ttyACM*", RUN+="/bin/chmod a+rw $env{DEVNAME}"
ACTION=="add", SUBSYSTEM=="tty", DEVPATH=="*ttyS*", RUN+="/bin/chmod a+rw $env{DEVNAME}"
ACTION=="add", DEVPATH=="*video*", RUN+="/bin/chmod a+rw $env{DEVNAME}"
  • reload udev rules: udevadm control --reload-rules
  • apply new permissions: udevadm trigger --action=add
  • watch udev activity: udevadm monitor -p

Disable modem-manager

The modem-manager will try to talk to any serial devices attached to USB serial ports. It assumes that those devices are modems and will send out modem-specific commands. if the devices are not modems and do not understand or do not like modem commands, well that's too bad. modem-manager is installed by the ModemManager package required by the NetworkManager package, and there is no configuration setting to turn modem-manager off.

One way to disable it is: chmod a= /usr/sbin/modem-manager

Another way to disable it is by forced uninstall: rpm --erase --nodeps ModemManager

Remember to kill the running copy: killall -KILL modem-manager

Caveat: it is not clear if modem-manager would not be resurrected by an update to the NetworkManager or ModemManager packages.

Configure Altera jtagd

(if needed)

mkdir /etc/jtagd
echo 'Password = "123";' > /etc/jtagd/jtagd.conf
cp -pv  /daq/daqshare/olchansk/altera/11.0/quartus/linux/pgm_parts.txt /etc/jtagd/jtagd.pgm_parts
  • start local jtagd: /daq/daqshare/olchansk/altera/11.0/quartus/bin/jtagd
  • test local connection: /daq/daqshare/olchansk/altera/11.0/quartus/bin/jtagconfig
  • test remote connection (add this machine to your .jtag.conf, run jtagconfig

For more information, go to Quartus

Install EOS

Instructions from here:

rpm -vh --install
yum-config-manager --disable eos-citrine # disable auto-update because all packages are not signed
yum-config-manager --disable eos-dep # disable auto-update because all packages are not signed.
yum install eos-client eos-fuse --enablerepo=eos-citrine

Install fix for the el7 systemd dbus boot hang

Around early Summer 2018 el7 started showing a boot problem. In the nutshell, there is a problem with the dbus connection between dbus and systemd that prevents polkit, firewalld, etc from starting. The system eventually boots enough that one can ssh into it, but most things do not work. Notably, polkit is not running, firewalld is not running, ssh login takes about 15-30 second.

Solution is to add a special systemd service to check that dbus started correctly. It that runs after dbus is started, but before it is used, and it restarts dbus in a loop with a delay until dbus starts correctly. In testing, dbus always starts correctly after the first retry.

cd ~root/git/scripts/etc
git pull
/bin/cp -vf systemd-check-dbus.perl /usr/bin/
/bin/cp -vf systemd-check-dbus.service /etc/systemd/system/
systemctl daemon-reload
systemctl enable systemd-check-dbus
systemctl start systemd-check-dbus
systemctl status systemd-check-dbus

After linux boots, if everything was okey, the script will report this:

[root@iris01 ~]# systemctl status systemd-check-dbus
Feb 08 17:15:49 systemd[1]: Starting Check that systemd is registered with dbus...
Feb 08 17:15:49 sh[4283]: Starting check for systemd dbus connection
Feb 08 17:15:50 sh[4283]: List:       string "org.freedesktop.DBus"
Feb 08 17:15:50 sh[4283]: List:       string "org.freedesktop.systemd1"
Feb 08 17:15:50 sh[4283]: systemd1 dbus service exists, success!
Feb 08 17:15:50 sh[4283]: Finished check for systemd dbus connection
Feb 08 17:15:50 systemd[1]: Started Check that systemd is registered with dbus.

If the boot problem happened, the script will report about restarting dbus.

Note: the systemd service file adjusts the start order of other services, this adjustment seems to reduce the probability of the problem.

Configure GRUB boot loader (CentOS7, CentOS8)

  • emacs -nw /etc/default/grub, remove "rhgb" and "quiet" from GRUB_CMDLINE_LINUX
  • grub2-mkconfig -o /boot/grub2/grub.cfg
  • grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg
  • grub2-editenv list # show contents of boot environement file
  • /bin/rm /boot/grub2/grubenv # remove stale settings, make grub2 boot from first entry in config file

Install memtest86+ (CentOS7, CentOS8)

yum -y install memtest86+
/bin/cp -vf /usr/share/memtest86+/20_memtest86+ /etc/grub.d/
/bin/chmod a+x /etc/grub.d/20_memtest86+ 
grub2-mkconfig -o /boot/grub2/grub.cfg

Disable ELREPO

sed 's/enabled=.*/enabled=0/' -i /etc/yum.repos.d/elrepo_triumf.repo
sed 's/enabled=.*/enabled=0/' -i /etc/yum.repos.d/elrepo.repo

Reduce install size (optional)

This is optional. Only do this if reducing the size of the OS image is very important.

Do this for VME processors.

yum erase "texlive*" "java*" "boost*" libreoffice"*"
#yum erase "xemacs*"
yum erase "libstdc++-docs"
yum erase firefox google-chrome"*"
yum clean all
/bin/rm -rf /usr/share/help
/bin/rm -rf /usr/share/doc

Update from el7.6 to el7.7

yum-config-manager --disable zfs
yum-config-manager --disable zfs-kmod
yum-config-manager --disable zfs-testing-kmod
yum versionlock delete zfs
yum versionlock delete kernel
yum -y update "yum*" "rpm*"
yum -y erase libqtxdg lxqt-qtplugin ### LXQT is not compatible
yum update
after rebooting into el7.7, follow instructions for updating ZFS from version 0.7 to 0.8.

Update ZFS

Switch from LADD-NIS to DAQ-NIS

domainname DAQ-NIS
/usr/lib64/yp/ypinit -s daq00
ls -l /var/yp
sed -i s/LADD-NIS/DAQ-NIS/ /etc/yp.conf
sed -i s/LADD-NIS/DAQ-NIS/ /etc/sysconfig/network
systemctl restart ypserv
systemctl restart ypbind
ypwhich -m

Finish installation


Special hardware settings

ASUS Crosshair mobo

  • use BIOS version 1207 or newer
  • (before CentOS7) sensors need these drivers from ELREPO: yum install --noplugins kmod-it87 kmod-k10temp; sensors-detect; service lm_sensors restart; sensors
  • CentOS7: installs correct drivers automatically

ASUS Crosshair-II mobo

  • use BIOS version 2607 or newer
  • for the onboard IDE to work, add "all-generic-ide" to kernel boot options in grub.conf
  • sensors need these drivers from ELREPO: yum install --noplugins kmod-it87 kmod-k10temp; sensors-detect; service lm_sensors restart; sensors

ASUS P7P55D EVO mobo

  • use BIOS version 2004 or newer
  • SL6 - install special driver for on board PCIe GigE network port and disable on board PCI GigE network port:
    • yum --enablerepo elrepo install kmod-r8168 kmod-r8169
    • # do not do this: sed 's/^blacklist/#blacklist/' -i /etc/modprobe.d/blacklist-r8169.conf
    • reboot
    • verify that correct drivers are loaded: ethtool -i eth0; ethtool -i eth1
    • note: there will be no eth1 - r8169 driver is disabled.

ASUS P6X58-E-WS mobo

  • BIOS settings
    • F1 or DEL to enter BIOS setup, F8 boot menu
    • go to POWER->HW mon, confirm CPU temperature is around 30C. (heatsink is installed correctly. Bad heatsink temperature quickly goes up to 50-70C).
    • Main menu: Storage config - SATA change IDE->AHCI
    • System information: confirm BIOS version 301, CPU type, memory size
    • AI Tweak: set DRAM frequency - AUTO->DDR3-1333
    • Advanced->Onboard devices: LAN BOOT: enabled
    • Power->HW monitor: CPU Q-FAN: enabled
    • Boot->Settings: Quick boot: enabled; Full screen logo: disabled; Wait for F1: disabled
    • Save and exit

ASUS E35M1-M PRO mobo

  • use BIOS version 1002 or newer
  • for CPU temperature: install kmod-k10temp from ELREPO (kmod-k10temp-0.0-4.el6.elrepo.x86_64.rpm)
  • for Sensors: yum --enablerepo elrepo install kmod-w83627ehf; modprobe w83627ehf; sensors
  • for Graphics: yum --enablerepo elrepo install kmod-fglrx fglrx-x11-drv
  • to enable booting from USB3, edit /etc/dracut.conf, change line "add_drivers" to read: add_drivers+="xhci-hcd"
  • to use multiple monitors, run "aticonfig --initial --heads=2 --adapter=1 --xinerama=on", to change screen layout, edit /etc/X11/xorg.conf. Only dual monitors DVI+HDMI seem to work. Tripple monitors does not seem to work.

Sensors instructions below are obolete (use driver from ELREPO)

cd ~root
echo "modprobe hwmon; modprobe hwmon-vid; modprobe k10temp; rmmod w83627ehf; insmod /root/w83627ehf.ko" >> /etc/rc.local

ASUS E45M1-M PRO mobo


  • use BIOS version 4901. Older versions seem to be ok: 3101, 3401, 4701, 4802 or newer. If BIOS is 1305 or older, install P9X79-WS-CAP-Converter.ROM (BIOS 2902/3101), then the new BIOS.
  • (not needed for CentOS7) for CPU temperature, install coretemp
  • (not needed for CentOS7) for sensors, install driver for NCT6776F chip same as E35M1-M above.
  • BIOS Settings:
    • enter "Advanced mode"
    • Ai Tweaker -> Ai Overclock Tuner -> Set to "XMP" - this enables DDR3-1600 RAM speed vs DDR3-1333 by default
    • ### NOT THIS: Monitor -> CPU fan speed low limit -> Set to "200 RPM" - we are using high efficiency slow turning CPU coolers and the default 600 RPM is right on the edge of firing false warnings
    • Monitor -> disable Q-fan on for all fans - let all fans always run at maximum RPMs
    • Boot -> Full screen logo -> Set to "disabled"
    • Wait for F1 -> Set to "disabled"


  • use BIOS version 6103 or newer
  • for CPU temperature, install coretemp
  • for sensors, install driver for NCT6776F chip same as E35M1-M above.


  • yum install kmod-w83627ehf.x86_64 coretemp
  • xemacs -nw /etc/rc.local, add:
modprobe coretemp
modprobe w83627ehf


cd ~root
echo modprobe hwmon-vid >> /etc/rc.local
echo insmod /root/nct6775.ko >> /etc/rc.local


the nct6775 driver does not work because of conflict with ACPI.


  • use bios 3801
  • set XMP mode (DDR4-2400)
  • Advanced->On board devices: set sata mode to "M2", set PCIe slot 3 to "x4"
  • boot: disable f1, disable logo, disable numlock


  • use BIOS 602 or later
  • SL6.5 installer cannot use USB2 ports and the network. Use USB3 ports (blue colour) to boot USB installer (memtest, rescue, etc)
  • SL6.5 kernels require boot option "iommu=soft" or USB2 and network do not work. (USB3 - blue ports - seems okey)
  • install ATI/AMD video drivers from ELREPO (see below)
  • sensors chip is ITE IT8623E, for SL6, use standalone driver from lm_sensors. (2 fans rpm, 2 temperatures):
cd ~root
echo modprobe hwmon_vid >> /etc/rc.local
echo insmod /root/it87.ko >> /etc/rc.local
. /etc/rc.local
  • for el7 use it87.ko driver:
cd ~root
echo modprobe hwmon_vid >> /etc/rc.local
echo insmod /root/it87.ko >> /etc/rc.local
. /etc/rc.local
  • sensors output:
[root@midemma02 ~]# sensors
Adapter: PCI adapter
temp1:        +22.0°C  (crit = +120.0°C, hyst = +90.0°C)

Adapter: PCI adapter
power1:           N/A  (crit =  25.00 W)

Adapter: PCI adapter
temp1:        +22.2°C  (high = +70.0°C)
                       (crit = +70.0°C, hyst = +69.0°C)

Adapter: ISA adapter
in0:          +0.96 V  (min =  +2.50 V, max =  +2.95 V)  ALARM
in1:          +2.23 V  (min =  +0.94 V, max =  +1.22 V)  ALARM
in2:          +2.03 V  (min =  +0.74 V, max =  +0.77 V)  ALARM
in3:          +2.00 V  (min =  +1.26 V, max =  +0.13 V)  ALARM
in4:          +2.23 V  (min =  +2.95 V, max =  +2.15 V)  ALARM
3VSB:         +3.36 V  (min =  +6.00 V, max =  +2.50 V)  ALARM
Vbat:         +3.22 V  
+3.3V:        +3.36 V  
fan1:         611 RPM  (min =  200 RPM)
fan2:         707 RPM  (min =  600 RPM)  ALARM
temp1:        +38.0°C  (low  = +122.0°C, high = +122.0°C)  sensor = thermistor
temp2:        +22.0°C  (low  = +119.0°C, high = -35.0°C)  ALARM  sensor = thermistor
temp3:       -128.0°C  (low  = +16.0°C, high = +93.0°C)  sensor = thermistor
intrusion0:  ALARM

[root@midemma02 ~]# 
  • AMD "Athlon(tm) 5350 APU" graphics supports 2 monitors maximum (mobo has 3 video outputs, only 2 can be used together)

Intel SE7230NH1

  • front panel header connector pinout is like this:
PWR LED | 1  2|
        | 3  4|
PWR LED | 5  6|
HDD LED | 7  8|
HDD LED | 9 10|
PWR SW  |11 12| NIC1 LED
PWR SW  |13 14| NIC1 LED
RST SW  |15 16|
RST SW  |17 18|
        |19 20|
NMI SW  |21 22| NIC2 LED
NMI SW  |23 24| NIC2 LED
...     |...  |
        |33 34|

ASUS H110M-A/M.2

  • use BIOS 2003 or later
  • dmidecode | grep -i nct reports: Nuvoton NCT5539D
  • sensors chip is "NCT6793D or compatible chip", for el7, use this driver:
cd ~root
echo modprobe hwmon-vid >> /etc/rc.local
echo insmod /root/nct6775.ko >> /etc/rc.local
  • sensors output:
[root@daq03 ~]# sensors
Adapter: Virtual device
temp1:        +27.8°C  (crit = +119.0°C)
temp2:        +29.8°C  (crit = +119.0°C)

Adapter: ISA adapter
in0:                       +0.34 V  (min =  +0.00 V, max =  +1.74 V)
in1:                       +1.02 V  (min =  +0.00 V, max =  +0.00 V)  ALARM
in2:                       +3.39 V  (min =  +0.00 V, max =  +0.00 V)  ALARM
in3:                       +3.39 V  (min =  +0.00 V, max =  +0.00 V)  ALARM
in4:                       +1.02 V  (min =  +0.00 V, max =  +0.00 V)  ALARM
in5:                       +0.15 V  (min =  +0.00 V, max =  +0.00 V)  ALARM
in6:                       +0.97 V  (min =  +0.00 V, max =  +0.00 V)  ALARM
in7:                       +3.38 V  (min =  +0.00 V, max =  +0.00 V)  ALARM
in8:                       +3.12 V  (min =  +0.00 V, max =  +0.00 V)  ALARM
in9:                       +1.00 V  (min =  +0.00 V, max =  +0.00 V)  ALARM
in10:                      +0.14 V  (min =  +0.00 V, max =  +0.00 V)  ALARM
in11:                      +0.12 V  (min =  +0.00 V, max =  +0.00 V)  ALARM
in12:                      +0.14 V  (min =  +0.00 V, max =  +0.00 V)  ALARM
in13:                      +0.12 V  (min =  +0.00 V, max =  +0.00 V)  ALARM
in14:                      +0.13 V  (min =  +0.00 V, max =  +0.00 V)  ALARM
fan1:                     1041 RPM  (min =    0 RPM)
fan2:                     1020 RPM  (min =    0 RPM)
fan5:                        0 RPM  (min =    0 RPM)
fan6:                        0 RPM
SYSTIN:                   +119.0°C  (high = +98.0°C, hyst = +95.0°C)  sensor = thermistor
CPUTIN:                    +26.5°C  (high = +80.0°C, hyst = +75.0°C)  sensor = thermistor
AUXTIN0:                   +27.5°C    sensor = thermistor
AUXTIN1:                  +112.0°C    sensor = thermistor
AUXTIN2:                  +111.0°C    sensor = thermistor
AUXTIN3:                  +111.0°C    sensor = thermistor
PECI Agent 0:              +28.0°C  (high = +98.0°C, hyst = +95.0°C)
                                    (crit = +100.0°C)
PECI Agent 0 Calibration:  +25.5°C  
PCH_CHIP_CPU_MAX_TEMP:      +0.0°C  
PCH_CHIP_TEMP:              +0.0°C  
intrusion0:               ALARM
intrusion1:               ALARM
beep_enable:              disabled

Adapter: ISA adapter
Physical id 0:  +31.0°C  (high = +80.0°C, crit = +100.0°C)
Core 0:         +31.0°C  (high = +80.0°C, crit = +100.0°C)
Core 1:         +28.0°C  (high = +80.0°C, crit = +100.0°C)

[root@daq03 ~]# 

Supermicro X11SSH-F

[root@alpha00 ~]# more /etc/modprobe.d/blacklist.conf
blacklist mei
blacklist mei_me
[root@alpha00 ~]# 
  • mobo requires M.2 PCIe SSD (M.2 SATA SSD would not work. SATA SATA SSD ok)
  • boot from M.2 PCIe SSD requires UEFI boot (from an MSDOS partition on the SSD)


  • BIOS 2417 is okey, upgrade to this if older
  • do not set XMP memory mode
  • in the BIOS, enable the boot compatibility support module mode: BIOS (press DEL) -> Advanced mode -> BOOT -> CSM Module -> Enable CSM "yes".
  • for SL6, install e1000e driver from ELREPO:
yum install --enablerepo=elrepo kmod-e1000e
  • sensors chip appears to be "Nuvoton NCT6798D" not clear what driver to use
  • dmidecode | grep -i nct reports: Nuvoton NCT6798D
  • kmod-nct6775-0.0-5.el7_7.elrepo.x86_64.rpm from ELrepo finds the chip but bombs because of conflict with ACPI


Configure X11 graphics

Special settings for DAQ

  • add the following at the end of /etc/X11/xorg.conf. The enables Ctrl-Alt-KP-/ and Ctrl-Alt-KP-* to unlock the keyboard after Altera Quartus crash:
Section "ServerFlags"
        Option "AllowDeactivateGrabs" "true"
        Option "AllowClosedownGrabs" "true"

Install NVIDIA drivers

  • yum --enablerepo=elrepo install nvidia-detect
  • run: nvidia-detect
  • as instructed by nvidia-detect, install correct driver:
    • yum --enablerepo=elrepo install kmod-nvidia
    • yum --enablerepo=elrepo install kmod-nvidia-304xx
    • yum --enablerepo=elrepo install kmod-nvidia-173xx
  • (before SL6.x: if it fails due to conflict with module-init-tools, run "yum --disablerepo \* --enablerepo elrepo update module-init-tools")
  • yum erase xorg-x11-glamor ### see (search for glamor)
  • mv /etc/X11/xorg.conf /etc/X11/xorg.conf-xxx
  • nvidia-xconfig
  • (SL6) reboot
  • (SL5) /dev/MAKEDEV nvidia
  • (SL5) restart the X11 server (Ctrl-Alt-Backspace or "killall Xorg gdm-binary")
  • observe that X11 server restarts using the NVIDIA driver (big NVIDIA logo on startup)
  • if needed, login as root and run "nvidia-settings" to setup dual-screen configuration, etc

Install legacy NVIDIA drivers

For old NVIDIA cards:

  • GeForce FX 5500
sh ./
  • GeForce 6200 - NVIDIA Corporation NV44A [GeForce 6200]
yum install nvidia-x11-drv-304xx-304.121 --enablerepo=elrepo
rmmod nvidia
killall gdm-binary
login as root
nvidia-settings to setup multiple displays

Install ATI/AMD drivers

  • yum --enablerepo elrepo install kmod-fglrx fglrx-x11-drv
  • check that /etc/X11/xorg.conf section "Device" entry "Driver" says "fglrx"
  • run "aticonfig --initial" to create xorg.conf if existing one is not good
  • run "amdcccle" as root to configure dual-screens, etc
 Note: 'amdcccle' is a GUI, so you must run this command from within a running X session
  • killall Xorg

Install ATI/AMD drivers (CentOS7)

NOTE: if both drivers - radeon and fglrx are loaded, boot will hang. the radeon driver is supposed to be blacklisted through grub rdblacklist=radeon entry which is installed by running grub2-mkconfig.

Install Intel drivers for HD4600/Z87

SL6.5 has the required drivers for the socket 1150 machines with Intel HD4600 graphics and Z87 chipset.

ASUS Z87 WS motherboard has these video connections with corresponding Intel video port assignements, as reported by "xrandr":

  • DisplayPort - DP1/HDMI1
  • MiniDisplayPort - DP2/HDMI2
  • HDMI - HDMI3

Due to hardware limitations, 3 HDMI monitors using 2 passive DP-HDMI adapters (and 1 straight HDMI) cannot be used.

To use 3 monitors do this:

  • 1st monitor: DisplayPort - DP-to-HDMI-passive-adapter - HDMI monitor (not tried: DP-to-DP-cable - DisplayPort monitor).
  • 2nd monitor: MiniDisplayPort - MiniDP-to-DP-cable - DisplayPort monitor
  • 3rd monitor: HDMI - HDMI-cable - HDMI monitor

With the monitors I have (Dell 1920x1200 VGA-HDMI-DP), the software thinks that there are 4 monitors: somehow both DP2 and HDMI2 see 1 minitor each, but the hardware cannot drive 4 monitors, so everything goes blank. To fix, disable HDMI2 (xrandr -display :0 --output HDMI2 --off) and enable DP2 (xrandr -display :0 --output DP2 --auto).

How to make this configuration permanent and how to assign monitor locations (left-right, etc), you figure it out.

Manual selection of monitor, video mode and resolution

Automatic selection of monitor and video mode usually works. When it does not, configure it manualls:

  • physically go to the computer
  • login as root
  • run "nvidia-settings" on machines using the NVIDIA driver
  • run "aticonfig" on machines with the ATI/AMD driver (use "aticonfig --initial" for initial setup, and good luck with anything more complicated)
  • run "system-config-display".
    • In the "hardware" tab, select monitor type: "generic LCD 1280x1024" or "generic LCD 1600x1200".
    • In the "settings" tab, select "1280x1024" or "1600x1200" and "Thousands of colors".
    • Press "ok", the display settings application should close.
  • Logout, the new login window should use the new settings.

Disable screen saver

If machine is booted without any monitor connected, current video cards to not enable any video outputs. If a monitor is connected later, there is no video image and there is no easy way to get a video image.

This can be solved by configuring X11 to always enable some video output. Because the monitor type is not known when X11 starts, one has to select some standard video mode (i.e. VESA 1280x1024) on some video output (VGA, DVI or HDMI).

Only NVIDIA cards with the NVIDIA driver (from EPEL) is supported by these instructions.

  • create default xorg.conf: nvidia-xconfig
  • edit /etc/X11/xorg.conf
  • add monitor section for the fake monitor:
Section "Monitor"
    Identifier     "Monitor0"
    VendorName     "Unknown"
    ModelName      "Unknown"
    HorizSync       31.0 - 83.0
    VertRefresh     59.0 - 61.0
    Option         "DPMS" "off"
    ModeLine "1280x1024"   108.00   1280 1328 1440 1688   1024 1025 1028 1066 +hsync +vsync
  • add output selection in the "Device" section:
Section "Device"
    Identifier     "Device0"
    Driver         "nvidia"
    VendorName     "NVIDIA Corporation"
    BoardName      "GeForce 210"
    #Option "ConnectedMonitor" "DFP"
    #Option "ConnectedMonitor" "CRT"
    Option "ConnectedMonitor" "CRT-1"
    Option "UseEDID" "no"
  • add fake video mode to the "Screen" section:
Section "Screen"
    Identifier     "Screen0"
    Device         "Device0"
    Monitor        "Monitor0"
    DefaultDepth    24
    SubSection     "Display"
        Depth       24
        Modes       "1280x1024"
  • disable screen saver and DPMS power off in the "ServerLayout" or "ServerFlags" section:
Section "ServerLayout"
    Identifier     "Layout0"
    Screen      0  "Screen0" 0 0
    InputDevice    "Keyboard0" "CoreKeyboard"
    InputDevice    "Mouse0" "CorePointer"
    Option         "Xinerama" "0"
    Option         "BlankTime" "0"
    Option         "StandbyTime" "0"
    Option         "SuspendTime" "0"
    Option         "OffTime" "0"

Section "ServerFlags" 
    Option         "BlankTime" "0" 
    Option         "StandbyTime" "0" 
    Option         "SuspendTime" "0" 
    Option         "OffTime" "0" 

Finish installation

  • logout and reboot the computer to have all the changes to take effect

Configure HTTPS server (CentOS7)

This will configure the HTTPS/SSL certificate using "certbot" and "letsencrypt" and configure an HTTPS web server using apache httpd.

First, configure apache httpd:

  • execute these commands:
yum install -y mod_ssl certwatch crypto-utils
cd /etc/httpd/conf.d/
mv ssl.conf ssl.conf-not-used ### remove the stock ssl.conf which refers to the localhost certificate that will expire in 1 year
touch ssl.conf ### create a blank file to prevent automatic updates from installing a stock ssl.conf file
# this is done later: rm /etc/pki/tls/certs/localhost.crt
  • create new file ssl-daq12.conf # use actual hostname instead of daq12
Listen 443 https
#SSLPassPhraseDialog exec:/usr/libexec/httpd-ssl-pass-dialog
SSLSessionCache         shmcb:/run/httpd/sslcache(512000)
SSLSessionCacheTimeout  300
SSLRandomSeed startup file:/dev/urandom  256
SSLRandomSeed connect builtin
SSLCryptoDevice builtin

<VirtualHost *:443>
DocumentRoot /var/www/html
ErrorLog /var/log/httpd/daq12.log
SSLEngine on
# note SSLProtocol, SSLCipherSuite and some other settings are overwritten by /etc/letsencrypt/options-ssl-apache.conf
# new SSL settings: K.O. Jan 2020, SSLlabs rating "A+"
SSLProtocol all -SSLv2 -SSLv3 -TLSv1 -TLSv1.1
SSLHonorCipherOrder on
# pervious SSL settings:
#SSLProtocol all -SSLv2 -SSLv3
SSLCertificateFile /etc/pki/tls/certs/localhost.crt
SSLCertificateKeyFile /etc/pki/tls/private/localhost.key
#SSLCertificateChainFile /etc/pki/tls/certs/server-chain.crt
#ProxyPass /elog/ http://localhost:8082/ retry=1
#ProxyPass /      http://localhost:8080/ retry=1
Header always set Strict-Transport-Security "max-age=31536000; includeSubDomains"
<Location />
AuthType Basic
AuthName "DAQ password protected site"
Require valid-user
# create password file: touch /etc/httpd/htpasswd
# to add new user or change password: htpasswd /etc/httpd/htpasswd username
AuthUserFile /etc/httpd/htpasswd
  • stop httpd from listening on port 80: edit /etc/httpd/conf/httpd.conf, comment-out the line "Listen 80"
  • enable and start httpd:
systemctl enable httpd
systemctl restart httpd
systemctl status httpd
  • try to access
    • you should see a complaint about self-signed certificate
    • you should see a request for password (do not login yet)
    • if you get "connection refused", HTTPS port 443 may need to be enabled in the local firewall, then try again:
firewall-cmd --add-port=443/tcp --permanent
firewall-cmd --reload
firewall-cmd --list-all

Second, configure certbot:

(Note: as of 2018-01-18 certbot requires use of http port 80 to get the initial https certificate, renewal can continue to use the https port 443)

(Note: as of 2019-01-?? certbot requires use of port 80 for renewals)

  • check that port 80 is not used by anything:
  • netstat -an | grep LISTEN | grep ^tcp | grep 80
  • lsof -P | grep -i tcp | grep LISTEN | grep 80
  • if lsof reports that httpd is listening on port 80, follow the httpd instructions above (remove "listen 80" from httpd.conf
  • install certbot and open tcp port 80 in the firewall:
yum install -y certbot python2-certbot-apache # (from EPEL)
firewall-cmd --add-port=80/tcp --permanent
firewall-cmd --reload
firewall-cmd --list-all
  • certbot certonly --standalone --installer apache # then answer questions:
  • "activate HTTPS for" - say ok
  • "enter email address" - enter your own email address
  • "please read terms..." - read the terms and say "agree"
  • it will take a few moments...
  • "please choose..." - say "easy" (http access is disabled (a) by firewall, (b) by local configuration
  • "congratulations..." - say ok.
  • certbot install --apache --cert-name # then answer questions:
  • "choose redirect..." - say "1" (no redirect)
  • look inside ssl-daq12.conf to see that SSLCertificateFile & co point to certbot certificates in /etc/letsencrypt/live/
  • remove self-signed localhost certificate, it will expire in 1 year and cause warnings and complaints: rm /etc/pki/tls/certs/localhost.crt
  • enable automatic renewal
systemctl enable certbot-renew.timer
systemctl start certbot-renew.timer
systemctl list-timers --all
  • to check corrent renewal and to update the certbot config file in /etc/letsencrypt/renewal, run this:
certbot renew --standalone --installer apache --force-renewal

NOTE: this certificate will expire in 3 months, automatic renewal should work starting with certbot-0.12.0-4.el7.noarch. Certificate expiration should be automatically detected by "certwatch" and email will be sent to local root user, to be forwarded to an actual person by ~root/.forward.

Third, activate password protection:

  • as shown in the config file above, create password file and initial user: (replace "midas" with specific username)
touch /etc/httpd/htpasswd
htpasswd /etc/httpd/htpasswd midas

Final test:

From here:

  • Configure selinux to allow proxying
 setsebool -P httpd_can_network_connect 1
 systemctl restart httpd
  • enable proxy for MIDAS mhttpd - uncomment redirect in the config file above
  • enable proxy for ELOG - ditto

NOTE: if certbot fails with errors about 'module' object has no attribute 'pyopenssl', try this: pip install requests==2.6.0

Configure large RAID6 arrays

  • connect the disks
  • check the disks health
    • run smart-status.perl
  • partition the disks
    • yum install gdisk
    • gdisk /dev/sdX
    • delete all partitions: o
    • create new partition: n, enter, enter, enter, fd00 (default sizes, partition type fd00)
    • write and exit: w
  • check presence of all partitions:
    • /bin/ls -l /dev/sd*1
  • prepare to use an external bitmap file
    • touch /md6bitmap
    • edit /etc/fstab, change entry for root filesystem from: "defaults 1 1" to "defaults 0 0"
    • edit /boot/grub/grub.conf, change entry "kernel ... ro ..." to "kernel ... rw ..."
  • create raid array:
    • mdadm --create /dev/md6 --level=6 --bitmap=/md6bitmap --raid-devices=10 /dev/sd[b-k]1
    • mdadm -Ds >> /etc/mdadm.conf
    • cleanup /etc/mdadm.conf
    • echo "echo 16384 > /sys/block/md6/md/stripe_cache_size" >> /etc/rc.local
    • echo "echo 1 > /sys/block/md6/md/sync_speed_min" >> /etc/rc.local
    • source /etc/rc.local
  • observe raid array rebuild:
    • watch -d -n1 "cat /proc/mdstat"

Configure ZFS

Install ZFS

(from here:

Follow the instructions for "kABI-tracking kmod" - dkms modules seem to always mess up the system when upgrading to next release of zfs.

#rpm -vh --install
#yum install
#yum install
#yum install
#yum install
#yum install
#yum install
yum install
yum-config-manager --disable zfs
yum-config-manager --disable zfs-kmod
yum --enablerepo=zfs-kmod clean all
yum --enablerepo=zfs-kmod install zfs
#sed 's/^SELINUX=.*/SELINUX=disabled/' -i /etc/selinux/config
echo USE_DISK_BY_ID=\'yes\' >> /etc/default/zfs
#systemctl enable zfs-import-cache
#systemctl enable zfs-mount
#systemctl enable zfs-share
#systemctl enable zfs-zed
#shutdown -r now # required to load the zfs kernel modules and to disable selinux
modprobe zfs # should work
zpool status # should report no pools available
  1. Note: zfs and selinux and not compatible: with selinux enabled, files on zfs cannot be deleted (files are gone, but "df" does not go down, zfs-, see #

If ZFS kernel module does not load automatically at boot time, add this to load it manually:

ls -l /etc/sysconfig/modules/
cat > /etc/sysconfig/modules/zfs.modules <<EOF
if [ ! -e /sys/module/zfs ] ; then
  modprobe zfs;
chmod +x /etc/sysconfig/modules/zfs.modules

Update ZFS (CentOS-7.9)

  • update CentOS-7.x to latest point release
  • reboot to latest kernel
  • check that currently installed ZFS is 0.8.x (not 0.7 or older)
  • then update ZFS:
[root@daq16 ~]# zfs version
[root@daq16 ~]# yum --enablerepo=kmod-zfs update
[root@daq16 ~]# zfs version ### observe mismatched version numbers: 0.8.5 userspace vs 0.8.4 kernel module
  • reboot to activate the updated kernel module
  • zfs version again
[root@daq16 ~]# zpool version
  • zpool status in case some ZFS volume needs to be updated
[root@daq16 ~]# zpool status
  pool: z12tb
 state: ONLINE

Update ZFS 0.7 to 0.8

How to identify zfs 0.7: "zfs version" does not work, also "rpm -q zfs"

zfs 0.7 is obsolete.

To opdate to zfs 0.8 or newer, remove 0.7, then install new version per instructions above.

  • remove zfs 0.7
yum versionlock delete zfs ### versionlock not needed anymore
yum versionlock delete kernel ### versionlock not needed anymore
rm /etc/yum.repos.d/zfs.repo* ### delete old repo files
yum erase zfs spl
  • reboot
  • install new zfs per instructions above
  • zpool import -as
  • zpool status ### check if any pool needs to be upgraded
  • zpool upgrade zssd ### upgrade zfs pool features

Lock kernel and zfs packages


yum versionlock kernel
yum versionlock zfs
yum-config-manager --disable zfs
yum-config-manager --disable zfs-kmod

Follow generic ZFS instructions

Here: ZFS

performance notes

Go here: disk_benchmarks

Configure UEFI boot

Some mobo can boot from NVME (PCIe) SSDs only via UEFI boot. Do this:

  • partition the NVME SSD using gdisk (must be GPT partition table, must have MSDOS EFI partition size 512MiB)
[root@alpha00 ~]# gdisk -l /dev/nvme0n1
GPT fdisk (gdisk) version 0.8.6 ...
Found valid GPT with protective MBR; using GPT.
Disk /dev/nvme0n1: 500118192 sectors, 238.5 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): 1A82CC87-2757-44ED-980F-C78E3681D9D3
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 500118158
Partitions will be aligned on 2048-sector boundaries
Total free space is 2014 sectors (1007.0 KiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1            2048         1050623   512.0 MiB   EF00  EFI System
   2         1050624       500118158   238.0 GiB   8300  Linux filesystem
[root@alpha00 ~]# 
  • create filesystems
mkfs.msdos /dev/nvme0n1p1
mkfs.xfs /dev/nvme0n1p2
  • prepare EFI partition
mkdir /mnt/efi
mount /dev/nvme0n1p1 /mnt/efi
mkdir -p /mnt/efi/efi/boot
cd /mnt/efi/efi/boot
# with Ubuntu LTS 20.04
cp /boot/vmlinuz vmlinuz # copy the desired linux kernel
#cp /boot/initramfs initramfs.img # copy the matching initramfs file
cp /boot/initrd.img initrd.img # copy the matching initrd file
#from /home/olchansk/sysadm/syslinux/syslinux-6.03 copy
cp /home/olchansk/sysadm/syslinux/syslinux-6.03/efi64/efi/syslinux.efi .
cp /home/olchansk/sysadm/syslinux/syslinux-6.03/efi64/com32/elflink/ldlinux/ldlinux.e64 .
cp syslinux.efi bootx64.efi
  • create syslinux config file: syslinux.cfg
default linux
label linux
kernel vmlinuz
append ro root=/dev/nvme0n1p2 nomodeset initrd=initrd.img
  • prepare system partition
mkdir /mnt/tmp
mount /dev/nvme0n1p2 /mnt/tmp
rsync -avx / /mnt/tmp
cd /mnt/tmp
#edit etc/fstab
#edit etc/syslinux/selinux # set selinux to permissive mode because rsync did not copy the selinux labels
  • unmount and reboot
  • restore selinux labels after first boot
#login as root
cd /
restorecon -R / # can also add "-v" to see progress, but runs much slower
#edit /etc/sysconfig/selinux # enable selinux
#shutdown -r now # reboot with selinux enabled

Configure UEFI secure boot

The above instructions do not quite work if "secure boot" is enabled.

These modifications are needed:

  • ls -l /boot/efi/EFI/bootko/
total 140116
-rwxr-xr-x 1 root root      108 Feb 24 15:47 BOOTX64.CSV
-rwxr-xr-x 1 root root  1334816 Feb 24 16:16 bootx64.efi
-rwxr-xr-x 1 root root   217495 Feb 24 16:16 config-4.15.0-74-generic
-rwxr-xr-x 1 root root      105 Feb 24 15:47 grub.cfg
-rwxr-xr-x 1 root root   199952 Feb 24 16:16 grubx64.efi
-rwxr-xr-x 1 root root 58986147 Feb 24 16:16 initramfs.img
-rwxr-xr-x 1 root root 58986147 Feb 24 16:16 initrd.img-4.15.0-74-generic
-rwxr-xr-x 1 root root   139968 Feb 24 16:16 ldlinux.e64
-rwxr-xr-x 1 root root  1269496 Feb 24 15:47 mmx64.efi
-rwxr-xr-x 1 root root  1334816 Feb 24 16:16 shimx64.efi
-rwxr-xr-x 1 root root      171 Feb 24 16:16 syslinux.cfg
-rwxr-xr-x 1 root root      102 Feb 24 16:16 syslinux.cfg~
-rwxr-xr-x 1 root root   199952 Feb 24 16:16 syslinux.efi
-rwxr-xr-x 1 root root  4068355 Feb 24 16:16
-rwxr-xr-x 1 root root  8367768 Feb 24 16:16 vmlinuz
-rwxr-xr-x 1 root root  8367768 Feb 24 16:16 vmlinuz-4.15.0-74-generic
    • shmix64.efi is a copy from /boot/efi/EFI/ubuntu
    • bootx64.efi is a copy of shimx64.efi (maybe not needed?)
    • grubx64.efi is a copy of syslinux.efi
  • efibootmgr -c -d /dev/nvme0n1 -p 2 -w -L bootko -l '\EFI\bootko\shimx64.efi'
  • efibootmgr -v
root@daqubuntu:~# efibootmgr -v
BootCurrent: 0000
Timeout: 1 seconds
BootOrder: 0000,0001,0002
Boot0000* bootko        HD(2,GPT,5d1cac95-29dd-4d8a-a56e-a8f414dd4047,0x800,0x100000)/File(\EFI\BOOTKO\SHIMX64.EFI)
Boot0001* Hard Drive    BBS(HD,,0x0)..GO..NO........y.I.N.T.E.L. .S.S.D.P.E.K.K.W.1.2.8.G.7....................A.......................................<..Gd-.;.A..MQ..L.I.N.T.E.L. .S.S.D.P.E.K.K.W.1.2.8.G.7........BO
Boot0002* ubuntu        HD(2,GPT,5d1cac95-29dd-4d8a-a56e-a8f414dd4047,0x800,0x100000)/File(\EFI\UBUNTU\SHIMX64.EFI)..BO
  • NOTE: if, after running "efibootmgr -c", the UUID is zero, then it probably did not take and the entry will vanish after reboot. In my case the mistake was to use "-p 1" instead of "-p 2".

Boot sequence is this:

  • shmix64.efi - Microsoft-signed boot loader is accepted by secure boot, loads and runs
  • shimx64.efi loads and runs grubx64.efi, this file name is hardwired into the signed shim, cannot be changed
  • grubx64.efi is syslinux.efi (could be anything)
  • syslinux.efi runs, loads syslinux.cfg, loads the linux kernel, loads the initrd, runs the linux kernel with specified flags (ro root=...).

UEFI syslinux kernel update

To update the linux kernel booted by UEFI syslinux, use this script:

  • ~root/git/scripts/etc/update_efi.perl

Update SL6 ssh

Stock SL6 ssh is now very old and by default, cannot connect to current Ubuntu and MacOS sshd. In reverse their ssh cannot connect to SL6 sshd.

Workaround is to manually enable SL6-compatible settings.

root@daq00:~# ssh -oHostKeyAlgorithms=+ssh-rsa -oPubKeyAcceptedAlgorithms=+ssh-rsa ladd00

Solution is to install newer ssh on affected SL6 machines.

ssh root@sl6-machine
cd /opt
git clone
/bin/cp -pv /etc/ssh/*key* /opt/openssh/etc/ ### copy old ssh host keys
/opt/openssh/bin/ssh-keygen -A ### generate any missing ssh host keys
# test sshd /opt/openssh/sbin/sshd -p 2222 -d
/bin/mv /usr/sbin/sshd /usr/sbin/sshd-SL6
/bin/ln -s /opt/openssh/sbin/sshd /usr/sbin/
/bin/mv /usr/bin/ssh /usr/bin/ssh-SL6
/bin/ln -s /opt/openssh/bin/ssh /usr/bin/
service sshd restart

Build openssh:

ssh sl6-machine
cd git
git clone git://
cd openssh
xemacs -nw ./configure ### fix syntax error: line 28124 empty "if/then/else" block bombs out, fill it with "AAA=aaa"
./configure --prefix=/opt/openssh
make -j

Install openssh:

ssh root@sl6-machine
cd .../git/openssh
make install ### copies stuff to /opt/openssh
/opt/openssh/sbin/sshd -p 2222 -d ### test sshd
/opt/openssh/bin/ssh -v sl6-machine ### test ssh