Poor Disk Performance

[helin0x]

Any advice would be appreciated:

 

I'm running a 2k8r2 VM fresh install on a new EVO850 using unassigned devices. Device type is RAW, hyperv XML on there and using virtio drivers.

 

Built with mostly default options, but when in windows disk performance is terrible.. 100% usage with 1MB/s activity, this is causing no responding all over the place, average response on the system process 50'000ms!

 

I've followed the wiki suggestions and googled all afternoon to no avail.

 

Please advise: best FS for the host SSD, will have to be NTFS for guest OS?

 

I've built another 2008r2 vm on a slower SATAII SSD on different controller and same issues, locks and poor performance, same settings (smaller partition)

 

Host system: gigabyte ga-ex58-ud3r, xeon 5630L, 14*3TB reds, 1* evo 850 500GB, 1* agility 3 180GB, antex 1200

 

Cheers,

 

H

[dinoaus]

I was having the same issue with the windows locking up passing through a whole SSD. I changed the cache to 'none' and IO to 'native' which fixed the issue.

 

e.g.

 

<driver name='qemu' type='raw' cache='none' io='native' />

[helin0x]

That cache options I think is whats doing it.

 

Just made another 2k8r2 vm with cache none as you suggest (still disk raw) its now r/w @ 200MB/s instead of 1MB, with about 30ms disk latency instead of 50k!

 

Will install all windows updates and re-enable the cpu cores and addtional ram and get it identical to the the other VM and report back my findings about disk io

 

I've also reformatted the host SSD to xfs, stil using ntfs for the windows guest os