Customer is experinacing slow I/O performance on Groupwise post office server.

Customer is experiencing slow performance with Groupwise  post office.

Customer is running in a vmware virtualized environment.
Virtual machine is on a shared LUN
PostOffice is stored on /media/nss/MAIL
Customer is running Symantec and Microsoft Anti-virus scanners.

TSATEST effective MB/min was 60-100,  Avg. Open Time, 100-200us, Avg Close Time, 100-200us Avg. Read Time was 4700us

Customer moved LUN to faster storage.
TSATEST effective MB/min improved to 2000+ Avg. Open Time, 000us, Avg Close Time, 000us Avg. Read Time was 1400us

GroupWise is I/O intensive.  It requires the ability to read and write many small files with out any delays. Faster hardware was need to meet the needs of GroupWise.

Best Practices:

• 1 LUN per Virtual Machine
• When a LUN is share between multiple VM's, I/O will be compromised.
  
• Remove snapshots
• When running in VMware environment, change SLES kernel scheduler to noop
• Exclude virus scanning from the following:
• ._NETWARE
• /_admin
• /admin
• /media/nss/MAIL*
  *where MAIL is then name of the nss pool hosting the post office files.
  
• Disable the virus scanner if i/o performance is slow as a troubleshooting tool.
• When using NSS, there may be a small performance increase with the following nsscon commands:
• nss /NoATime=MAIL*
• nss /ReadAheadBlks=MAIL*:2 
  *where MAIL is then name of the nss pool hosting the post office files.