Setting Up IP over IB

We have 1 dual port HCA card installed. Assuming port 2 (ib1) is up and port 1 (ib0) is down.

Step 1

In /etc/sysconfig/network-scripts, create:

$ cat ifcfg-ib1
DEVICE=ib1
#HWADDR=80:00:00:49:FE:80:00:00:00:00:00:00:00:02:C9:03:00:0F:D8:5E
TYPE=InfiniBand
UUID=48c746a0-5536-408f-ae8f-c36be67c66c7
ONBOOT=yes
NM_CONTROLLED=no
BOOTPROTO=static
IPADDR=192.168.11.1
NETMASK=255.255.255.0

Step 2

$ /etc/init.d/openibd restart
$ /etc/init.d/network restart

Step 3

Verify the connectivity:

$ ifconfig
# Check if ib1 is up and has IP assigned

$ ibdev2netdev

Set up another node but with different IP, e.g. 192.168.11.2. From this new node you can ping the older node by
$ ping 192.168.11.1

Vi Tricks

http://stackoverflow.com/questions/235839/indent-multiple-lines-quickly-in-vi

Installing Google Chrome on CentOS 7.0 / 6.x

Create /etc/yum.repos.d/google-chrome.repo

Check if latest version of Chrome available from Google's repository by
# yum info google-chrome-stable

# yum install google-chrome-stable
This will fail.

Sadly, the Google Chrome browser no longer supports the most famous commercial distribution RHEL 6.x and its free clones such as CentOS and Scientific Linux.

However, there's this script by Richard Lloyd that

automatically download and install latest Google Chrome browser by picking libraries from a more recent released distro and put those libraries in (/opt/google/chrome/lib) directory and then you can able to run Google Chrome on RHEL/CentOS 6.x versions.

# wget http://chrome.richardlloyd.org.uk/install_chrome.sh

# chmod u+x install_chrome.sh

# ./install_chrome.sh


References
http://www.tecmint.com/install-google-chrome-on-redhat-centos-fedora-linux/

Cloning Compute Nodes

Assuming:

master is in sda

target is in sdb

dd if=/dev/sda of=/dev/sdb bs=32M

comment out entries in /etc/udev/rules.d/70-persistent-net.rules

Change hostname and IP of the master into the desired one.

Comment out HWADDR and UUID. 

Move sda to the new compute node.

Move sdb to sda of the original compute node. 

Data Transfer using Tar

Most common way of doing data transfer is scp and rsync. However, data transfer with tar is also possible.

An example using tar with pbzip2.

pbzip2 is a parallel compression utility.

From /opt/intel on host machine to /opt on a remote server called fuji103.

tar -cpf - --use-compress-prog=/apps/pbzip2/116/pbzip2 /opt/intel | ssh fuji103 "(source ~kevins/.bashrc; cd /opt/; tar --use-compress-prog=/apps/pbzip2/1.1.12/pbzip2 -xpf -)"

From NFS directory called /usr/local/opt/intel to local directory /opt.

tar -cpf - --use-compress-prog=/apps/pbzip2/116/pbzip2 /usr/local/opt/intel | tar --use-compress-prog=/apps/pbzip2/1.1.12/pbzip2 -xpf -

How to Check the Status of a License Server

On a remote server requiring the license:

#See some help messages
$ lmstat -h

See everything
$ lmstat -a

On the license server:

#Grab the port number
$ cat /usr/local/lsf/conf/license.dat

You can try to telnet to that port by
$ telnet localhost port_number

On the remote server:

#This will check the status of the license server on the remote server
$ lmstat -a -c port_number@license_server_address

Troubleshooting LDAP

Healthy:

slapd should be running

If not:

Check /var/log/ldap.log

If database corrupted, use db_recover -h <path-to-database>

<path-to-database> can be /var/lib/ldap, can be found on /etc/openldap/slapd.conf

A sample extract from /etc/openldap/slapd.conf
# The database directory MUST exist prior to running slapd AND
# should only be accessible by the slapd and slap tools.
# Mode 700 recommended.
directory       /var/lib/ldap

Make sure to:
$ chown -R ldap /var/lib/ldap && chgrp -R ldap /var/lib/ldap

If it does not work, check the backup (for instance /var/lib/ldap/backup) against the current database directory