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Showing posts from March, 2014

Configure DNS using resolvconf in Ubuntu 12.04 (Precise Pangolin)

Is /etc/resolv.conf useless in Ubuntu 12.04 LTS ? I say so, because when I configured the /etc/resolv.conf file and rebooted the VM, all the settings were overwritten.
piyush@co109044:~$ cat /etc/resolvconf/resolv.conf.d/tail
search romelab.it.ibm.com ibm.com
nameserver 9.168.127.100
namserver 9.168.96.100

piyush@co109044:~$ cat /etc/resolv.conf
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
search romelab.it.ibm.com ibm.com
nameserver 9.168.127.100
namserver 9.168.96.100

piyush@co109044:~$ reboot

Last login: Mon Mar 31 08:48:50 2014 from 9.77.94.202
piyush@co109044:~$ cat /etc/resolv.conf
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN

After rebooting the VM, all the settings of /etc/resolv.conf were overwritten.
After reading the release notes of Ubuntu, figured out that "r…

Understanding some conditional expressions for the Korn shell or POSIX shell

Read more about POSIX shell on wikipedia. Below are the set of commands to understand some of the expressions for writing portable shell scripts. Empty cells in the "Example" column is for you to practice.

Exit Status for the "test" command:
0 - The Expression parameter is true.
1 - The Expression parameter is false or missing.
>1 - An error occurred.
SyntaxDescriptionExample-a FileTrue, if the specified file is a symbolic link that points to another file that does exist.# touch file1
# ln -s file1 linktofile1
# ls -al linktofile1
# test -a linktofile1
# echo $?
0
# rm -f file1
# test -a linktofile1
# echo $?
1 -b FileTrue, if the specified file exists and is a block special file.All files in /dev are special files... they represent devices of the computer. (http://www.lanana.org/docs/device-list/devices-2.6+.txt)
# test -b /dev/ram0
# echo $?
0-c FileTrue, if the specified file exists and is a character special file.All files in /dev are special …

TSAM selects a host for resource allocation when its in maintaince mode ?

Typically some hosts from a resource pool can be in maintenance mode. In such situations customers can't wait till these hosts are out from the maintenance mode, neither can they stop new SRs ... However TSAM's bluecloud reservation is not aware that some hosts need to be skipped when trying to fit reservations.

In such cases, SRs will continue to fail for sitting on those hosts. Inorder to indicate to Bluecloud that a particular host must be skipped, set the "ignored-by-resource-broker" property to "true" for that host. This can be set from Maximo UI. Goto -> Service Automation -> Cloud Server Pool Administration. Select the required pool. From the Resource Pool Configuration tab, Goto the Resource Pool. Here you will be able to see the hosts included in this pool. For ever host to be ignored, check the "Is Failed" flag.


Also published at: http://www.cubicrace.com/2014/03/why-tsam-continues-to-select-host-for.html