Practical notes about WPARs

WPARs (Workload PARtitions) are the Big Blue's answer to Solaris zones or Linux containers.
Wpars were born in Aix 6.1 and they simply are "isolated" instances of AIX ;they are built
from the LPAR that host them , known as the global environment.
Two types of WPARs exist : System wpars and Application wpars.


Wpars allow us to run separate instances of applications or databases with a guaranteed
level of isolation even on the same LPAR.
Anyway these solutions are not recomendedfor all scenarios , for example wpars are
not the perfect choice when we have performance needs , because of the LPAR resources
sharing and contention with other wpars.
Another aspect that must to be considered is that it's true , wpars are isolated one with
each other but the Global Environment can see and interact with the wpars'processes
and resources; so , if security is a must for our solution wpars are not suitable.
There are other aspects that may tell us to not choose thes kind of partition, for example
it must be clear that a global environment shutdown impacts on all the wpars hosted by
that lpar.


Here follows some of the most common wpar-related  operations and commands.


- First , to create a system wpar by command line :
mkwpar -c -l -D rootvg=yes devname=hdisk3 -n syswpar -N address=11.22.33.44


It's not necessary to explain the command syntax as it is very simple ,we are passing
the disk name as the global environemnt names it , the wpar name and the ip address
it will use.
- To list a wpar details :
lswpar
lswpar -N – adds network related informations
lswpar -L – long listing , very detailed output
- To edit a wpar details :
chwpar -A syswpar – for example in this case we set the wpar to autostart at the global environment boot.


Obviously , as usual there is also the fast path smitty wpar.




Work in progress...