Slow Backup Performance on OES2 Sp1 Linux Virtual Machines

  • 7005707
  • 08-Apr-2010
  • 27-Apr-2012


Novell Open Enterprise Server 2 (OES 2) Linux Support Pack 1


The OES2 Sp1 Linux host was running as a virtual machine on a xen host box. This VM was backing up a couple of iscsi sans over the wire. Backup performance was extremely slow, around 1.7 megabits per second. File copies from this VM were very fast as far as users were concerned. Tsatest also showed this loss of performance. Backups or file copies that were not dependent on SMS were much faster.  The particular file system being backed up was not an issue. The same slowness occurred on any file system that SMS accessed.


There is a bug in SMS that is manifested if the VM has 4 gig of ram or any multiple thereof assigned to it such as 8, 16, 32, etc. The workaround is to assign an amount of ram to the VM that is not a multiple of 4. There is also a patch on the channel that contains a fix for this. This is found in the November 2009 release. If you are fully patched from the channel then this fix should be there.