Flexible Power Solutions from Starline

I came across this interesting flexible power solution from Starline - Busline Power Distribution. The track busway allows different types of customised power supplies and components to be planted on the track and it can be tapped instantly at any location along the track. It is interesting to know that we can put 3-phase and single-phase along the same track.

Do look at

1. Starline Videos 
2. Literature

Very need solution for flexible power deployment for DC.

Qsub and Interactive X Windows on CentOS

If you are using torque as a submission agent and wish to use interactive windows for your allocated node. You can use

Step 1:
Launch vncserver on the head node. For more information how to Using VNC Server on CentOS with Windows VNC Viewer

Step 2: Make sure you have configure the server allow ssh forwarding. At /etc/ssh/sshd_config

...
X11Forwarding yes
X11UseLocalhost yes
...

Restart the sshd services.

# service sshd restart

Step 3: Use the qsub command to launch interactive and. The "-X"

$ qsub -q myqueue -l nodes=1:ppn=8 -I -X

Total Reconfiguration of GPFS from scratch again

If you have messed things up in the configuration and wish to redo the entire setup again, you have to do the following. From our training at GPFS, there are 2 advisable ways. The first one is the recommended way. The latter one is the “nuclear” option.

For more information, see  Total Reconfiguration of GPFS from scratch again

Using Chage to manage password expiration and aging

As administrators, tools like chage to help manage the /etc/shadow information. /etc/shadow contains information such as

myuseid:$xxxxxxxxxeeerrrrr:15607:0:900:10:0::

Column	Description
1	UserID
2	Encrypted Password
3	Set the number of days since January 1st, 1970 when the password was last changed.
4	Minimum number of days between password changes to MIN_DAYS
5	Maximum number of days during which a password is valid
6	Set the number of days of warning before a password change is required
7	Set the number of days of inactivity after a password has expired before the account is locked
8	Set the date or number of days since January 1, 1970 on which the userid account will no longer be accessible. The date may also be expressed in the format YYYY-MM-DD

Best if you can use the command chage. For example, you can use the command

1. Listing of  password details

# chage --list  username

Last password change                                    : Feb 03, 2012
Password expires                                        : Jul 22, 2013
Password inactive                                       : Jul 22, 2013
Account expires                                         : never
Minimum number of days between password change          : 0
Maximum number of days between password change          : 60
Number of days of warning before password expires       : 10

2. Disable password aging for an user account

# chage -m 0 -M 99999 -I -1 -E -1 username

-m 0 (Min number of  days between password change to 0)
-M 99999 (Max Number of days between password change to 99999)
-I -1 (Set "Password Inactive" to never)
-E -1 (Set "Account expires" to never)

Last password change                                    : Feb 03, 2012
Password expires                                        : never
Password inactive                                       : never
Account expires                                         : never
Minimum number of days between password change          : 0
Maximum number of days between password change          : 99999
Number of days of warning before password expires       : 10

For more complete information, see

1.  6.6. Linux Password & Shadow File Formats
2. 7 Examples to Manage Linux Password Expiration and Aging Using chage

Basic Installation and Configuration of GPFS

I have written a few short basic tutorials on Installing and Configuring of IBM General Parallel File System (GPFS)

1. Basic Installing and Configuring of GPFS Cluster (Part 1)
2. Basic Installing and Configuring of GPFS Cluster (Part 2)
3. Basic Installing and Configuring of GPFS Cluster (Part 3)
4. Basic Installing and Configuring of GPFS Cluster (Part 4)

 Happy reading.