Monday, December 31, 2007

Comparing AIX 6.1 WPAR to the global AIX

Lets take a look around a WPAR and compare it to the global AIX
What can we find out from the global AIX about the WPARs we already have?
List the WPARs with lswpar

WPARs called wp03 and wp05 are active system Workload Partiotion but wp09 is only defined it can be made Active by running the "startwpar wp09" command.


State A=active
State D=defined
State B=broken
State T=transitory i.e. changing state
Type A=Application WPAR
Type S=System WPAR
In this example all my WPAR are have simple names starting with "wp" and then two digits. This is, or course, not mandatory.

What is in /wpars ?
This is a new directory specifically for WPAR use in this we find:

One sub-directory for each WPAR and in this sub-directory we find:

If you have used AIX much you will recognize this as the regular files and directories of AIX because that is pretty much what you get with an WPAR.

When I check the disk space use of a WPAR on the NFS server I find a basic just installed WPAR is using:

I make that around 25MB in size - this is a very small overhead. Remember by default the big filesystems like /usr and /opt are shared with the global AIX. If you really need a writable /usr, for example, this is possible but then you need to find the extra disk space too. If you have an application that is normally, installed in these filesystems (generally regarded as a poor application) then you can install it in the global AIX and every sharing WPAR can access the files - this can reduce the workload of installing applications a great deal.

List the mount points
The global AIX has its own mount point and the mount points for the WPARs it is hosting:

Here we see the regular mount points of AIX: /, /usr, /var, /tmp, /home, /opt
and then for each of the active WPAR there are additional mounts as below

NFS mount for the read/write private filesystem: /, /home. /tmp and /var
remounts to make them read-only of: /opt and /user
More WPAR details with lswpar -L
This "lswpar -L " list all the attributes of the WPAR


General section - has the basic information and where the WPAR data can be found
Network section - has the IP address etc.
Filesystems - note some local read-only filesystems nd some read-write and private over NFS in this case
Resources like Workload Manager (WLM) which has been part of AIX for years and years - see for details of how these are used as the WPAR resource control is built on top of WLM. When a WPAR is started a WLM Class is automatically created.
Operation - this WPAR has not been moved
Security based on Role Based Access Control (RBAC) - not covered here see the AIX Security Redbook for more details
Export devices are various items that the WPAR has which are distinct form the global AIX for security and performance
In the global AIX we can find the following out about the network:

See the network aliases ( and 113) that are used to "piggy back" the real network card in the global AIX with IP address The top line with the IP Address is the IP Address that the global AIX uses the lines below are the network aliases used by the WPAR - one each. This also highlights that the global AIX and WPAR needs to be in the same sub-net

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