vCenter Appliance Memory Tweaks

Posted on 11 December 2011

I’ve been playing around with the Virtual Center Server Appliance and a friend of mine pointed me to a post that has some memory tweaks that you can use to reduce the memory foot print of the appliance.

See the post on vCSA memory tweaks by Merijntje Tak here (and thanks to him for the information). In his post he describes a method to reduce the amount of RAM DB2 takes and also point to two other files that can be edited.

The following 3 files can be edited to allow you to reduce the RAM allocated to the vCSA.

/etc/vmware-vpx/tomcat-java-opts.cfg
/usr/lib/vmware-vsphere-client/server/bin/dmk.sh
Change the RAM allocated to DB2 as posted by Merijntje

/etc/vmware-vpx/tomcat-java-opts.cfg: Sets the heap size for the JVM (scratch memory)
Default: Xmx1024m MaxPermSize=256m. The Xmx=max heap size; MaxPermSize=permanent heap isn’t subject to garbage collection.
Tweaked: I had changed the Xmx to 512m but experienced stability issues so I’ve set it back to 1024m.

/usr/lib/vmware-vsphere-client/server/bin/dmk.sh: Startup script for vCenter Service.
Default: JAVA_OPTS=”$JAVA_OPTS -Xmx1024m -Xms512m -XX:PermSize-128m”. Xmx=max heap; Xms=starting heap.
Tweaked: JAVA_OPTS=”$JAVA_OPTS -Xmx512m -Xms512m -XX:PermSize-128m”. This has been stable.

DB2 Memory Tweak

Login to the vCenter linux box

Change to user db2inst1 (SU db2inst1)

Start the db2 utility (/opt/db2/current/bin/db2)

Issue the following statements (without quotes):
“connect to vcdb”
“select name, value from sysibmadm.dbmcfg where name = ‘instance_memory’”
“update dbm cfg using instance_memory 65536 immediate”. NOTE: I doubled my instance_memory to 131072

Category: Technology, Vmware

3 responses to vCenter Appliance Memory Tweaks

VMware VCenter Server Appliance (vCSA) | Squishnet says:

December 11, 2011 at 6:55 pm

[...] the vCSA more. It has been increasingly common during backups from VDR. I suspect some of the memory tweaks may be responsible for this [...]

Peter Dudley says:

January 13, 2012 at 9:42 pm

I’m getting the error
‘An error occurred while accessing the directory “/root”. I’m also a unix n00b. I guessing the account db2inst1 does not have the necessary rights on “/root”, but have no idea how I correct this. Can you provide any info?

PCD

Peter Dudley says:

January 13, 2012 at 9:50 pm

I guessed and found a solution.
do a ‘cd /opt/db2/current/bin’
then ‘db2′

No errors. Hopefully it will now use less memory.

Reply

Squishnet