Having throughput problems only on 1 VM

G

greengolftee87

Limp Gawd
Joined
Oct 15, 2008
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Im going crazy trying to figure out whats causing this. I have a 500 GB Hdd that has 2 vms on it. A server2003 vm which performs very well and an XP vm which performs terribly. The following are HDtune measurements. The host OS is WIN7 using virtualbox. The server 03 vm was brought over from a retired esxi 3.1 box and the xp vm was created by Vbox. Both are *.vmkd format.

HDD tested from host OS. No VM's running
CMpdFoK.png


tested from Server2003 VM. XP vm off
gB3G0T2.png


tested from XP vm. Server2003 vm off
dOClPue.png


I dont expect blazing performance from either one nor do I need it. However the XP vm is nearly unuseable. I'm at a loss of what to do.

EDIT: I should add that I have tried attaching the XP vmkd though both the ide and sata controll. It did not make a difference.
 
You've got some strange caching issues going on there.

The Server 2003 install looks a little high on the performance end almost like some advanced caching is working properly.

The XP side results are 100% false. You're HD isn't capable of 220MB reads. It looks like the virtual hard disk caching is going crazy on the XP VM.
 
Mackintire said:
You've got some strange caching issues going on there.

The Server 2003 install looks a little high on the performance end almost like some advanced caching is working properly.

The XP side results are 100% false. You're HD isn't capable of 220MB reads. It looks like the virtual hard disk caching is going crazy on the XP VM.
Click to expand...

agreed. Its like it builds up and then reads in bursts. is caching adjustable? Is it handled by the hypervisor or the vm filesystem?
 
SpaceHonkey said:
Does not matter - XP and 2003 by default do not align the first sector of the partition properly.

Have a look here -

http://blogs.vmware.com/vsphere/2011/08/guest-os-partition-alignment.html
Click to expand...

It seems like there are many tools out there for aligning a VM through vcenter but since Im no longer using that I may have to do a reinstall. However I checked both the xp and sever03 vms and they are identically misaligned so why would the xp vm perform so much worse?
 
Is vm tools installed in the 2003 vm and not the xp box? Perhaps driver performance issue?
 
Is vm tools installed in the 2003 vm and not the xp box? Perhaps driver performance issue?
Click to expand...

To add on to this, what controller are you using for the XP machine?
 
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