[CentOS-virt] SATA vs RAID5 vs VMware

Fri Sep 25 14:36:28 UTC 2009
Benjamin Franz <jfranz at freerun.com>

Philip Gwyn wrote:
> Hello,
> I have strange behaviour on a server that I can't get a handle on.  I have a
> reasonably powerful server running VMware server 1.0.4-56528.  It has a RAID5
> build with mdadm on 5 SATA drives.  Masses of ram and 2 XEON CPUs.  But it stutters.  
This will double your memory usage. But it should fix your I/O.

Take a look at http://vmfaq.com/?View=entry&EntryID=25
In particular, putting your temporary directory in a ramdisk will 
improve your I/O profile immensely.

Edit /etc/vmware/config and add:

tmpDirectory = "/tmp/vmware"
mainMem.useNamedFile = "FALSE"
sched.mem.pshare.enable = "FALSE"
MemTrimRate = "0"
MemAllowAutoScaleDown = "FALSE"
prefvmx.useRecommendedLockedMemSize = "TRUE"
prefvmx.minVmMemPct = "100"

Edit /etc/fstab and add

tmpfs                   /tmp/vmware             tmpfs   
defaults,size=100% 0 0

and edit /tmp/cron.daily/tmpwatch and add '-x /tmp/vmware' to the 
tmpwatch command line for /tmp.

make your mount point for /tmp/vmware and mount /tmp/vmware

restart vmware.

That is how I run my systems.

Benjamin Franz