Versioned WPAR on AIX 7.1

Hello everyone today i am going to share knowledge on how we can create versioned WPAR on AIX 7.1.

For creating versioned WPAR you need to pay some cost to IBM for versioned WPAR fileset .Version WPAR are supported on AIX 7.1 only.

So question is why we need version WPAR ??

Generally versioned WPAR is AIX 5.3 and AIX 5.2 instance running on AIX 7.1 .When client application or database having operating system version dependency then version WPAR come in picture.

 

Minimum OS requirement for creating versioned WPAR 

Global LPAR OS version :AIX 7.1 TL01 SP05 recommended .

Minimum AIX 7.1 TL01 SP04.

WPAR extention OS version :AIX 5.3 TL12 SP 05(minimum) and AIX 5.2 TL10 SP08(minimum).

Lets see step by step procedure how to create versioned WPAR on AIX 7.1 TL03 SP04.we going to create AIX 5.3 versioned WPAR on AIX 7.1

Hardware : IBM POWER8

Step 1:

First create fresh MKSYSB backup of  client LPAR OS (AIX 5.3 TL12 SP05).

Step 2: Create target AIX 7.1 TL03 SP04 LPAR and then install following licensed fileset on that GLOBAL LPAR.

licensed fileset for versioned WPAR.

vwpar.images.53            1.1.2.0  COMMITTED  Versioned WPAR 5.3 Support

vwpar.images.base          1.1.2.0  COMMITTED  Versioned WPAR Base Support

vwpar.sysmgt               1.1.2.0  COMMITTED  Versioned WPAR Management

bos.wpars                 7.1.3.30  COMMITTED  AIX Workload Partition

copy required versioned wpar fileset(IBM Licensed fileset)  on /tmp/wpar_5.3 path,which you purchased from IBM for creating versioned WPAR.

Step 3:Then

#cd  /tmp/wpar_5.3

#inutoc .

use smit install to install all fileset in path for supporting versioned WPAR of AIX 5.3.

Step 4:

After versioned wpar fileset installation completed check installed fileset using command.

#lslpp -l |grep -i wpar

Step 5:

Copy AIX 5.3  MKSYSB using NFS share to GLOBAL LPAR in file system /mksysb_AIX_LPAR/image/ path.

/mksysb_AIX_LPAR/image/lparb.mksysb

Step 6:

Assign 70 GB SAN disk on Global AIX 7.1 LPAR for WPAR install.

cd to path /mksysb_AIX_LPAR/image

Execute mkwpar command with following flag

# mkwpar -D rootvg=yes devname=hdisk1 -n wparb -h wparb -N interface=en0 netmask=255.255.255.0 address=XX.XX.XX.XX -r -C -B lparb.mksysb –l

Flag 

D  configure device from global LPAR to WPAR when system start

devname  device name to allocate to the versioned WPAR

rootvg=yes   use specified device as rootvg.

h   hostname

n   wpar name

N  interface name for IP configuration

r  Duplicate network configuration file from global LPAR

C Create versioned WPAR

B workload partition backup image (mksysb image)

l   Creates private and writable versions of the /usr and /opt file systems

Above command will take around 20-25 minutes

Once command completes it will show versioned wpar has been created successfully.

  

Step 7:Check versioned WPAR is active or not by following command

Following are the state of WPAR.

A  Active

D defined

Step 8:

#startwpar  wparb      

above command will start WPARB.for accessing wparb it must be in ACTIVE state.

Once wpar started login to WPAR using  command

#clogin  wparb

It will show AIX 5.3 versioned WPAR console

Thanks !!!

Fork function failed on AIX versioned WPAR.

Hello everyone today i am going to share knowledge about the error "fork function failed".
I faced this issue on AIX 5.3  versioned WPAR on AIX 7.1 TL03 SP4.

fork function - "it create new process"

On IBM POWER8 we had created versioned WPAR of AIX 5.3.so here you must be thinking that why this guy didn't install directly AIX 5.3 on POWER8 BOX ??
so answer to this query is ,we cant directly install AIX 5.3 on POWER8,so first we need to install AIX 7.1 TL03 and SP4 and on that need to create AIX 5.3 versioned WPAR by using AIX 5.3 MKSYSB image,also because of database dependency ,we not able to install latest version of AIX on POWER8.

Let me answer why we created Versioned WPAR 5.3 on AIX 7.1
1st reason is that we cant directly install 5.3 on POWER 8
2nd ,we need IBM support for versioned WPAR in case of any critical issue and IBM support AIX 5.3 Versioned WPAR on AIX 7.1.

Overall setup was like below.

BASE OS
AIX 7.1 TL03 SP4.
on top of this we created AIX 5.3 versioned WPAR which hosting oracle 9i database for critical application.After restoration of database on AIX versioned WPAR oracle team started database and
after 30-40 minutes ,oracle team was complaining ,when they trying to login oracle account they are getting error :

"The fork function failed. Too many processes already exist"

after doing analysis of this error we increased memory of AIX LPAR and again asked DBA team to start database again and check whether error is sorted out or not.but no success getting same error again.
so what next ??

from OS end our thinking was like if we restore OS MKSYSB then no need to change any OS tuning parameter,but when we started checking parameter for "MAXUPROC" ,we found culprit which was causing this error."MAXUPROC" wasn't correctly set on AIX global LPAR and versioned WPAR  and which causing fork function failed error.on source AIX  server it was 2048 and on target it was 128 on both BASE OS and versioned WPAR.

MAXUPROC = maximum number of oracle/application process a user can able run on AIX OS.
so because of wrong setting at target after migration database throwing error of reaching maximum limit 128 process on versioned WPAR.

our solution to this was like ,first change maxuproc on AIX 7.1 GLOBAL LPAR and then do changes on AIX 5.3 versioned WPAR. Here note one thing that if AIX admin didn't set maxuproc for WPAR then non-root user inherits maximum process limit from global AIX 7.1 LPAR.

Command to change "MAXUPROC"

# chdev -l sys0 -a maxuproc=2048 
and then reboot AIX 7.1 global LPAR
and after reboot change "totalProcessess" on wpar by command,
#chwpar -R totalProcessess=2048 wparname.
then stopwpar and startwpar once .

after setting correct MAXUPROC limit we sorted out fork function failed error .

at last we can say that maxuproc limit changes according  to database and application requirement,so 
its always wise decision to refer database and application tuning document for performance related issue.

Thanks !!!!