With the 6.0 "upgrade", KVM is running significantly slower than XEN (SOLVED)

[pyrater]

I am hoping i missed a critical step. I have two VM's (windows 8.1) running on a single cache drive. Both VM's are significantly slower than when i used Xen. Disk usage hits 100% on both VM's nearly all the time. I am using the drivers from virtio-win-0.1.96.iso. Any tips? Thoughts?

 

[dlandon]

Did you convert Xen VMs or install new in KVM?  My experience is that VMs are faster in KVM.

[pyrater]

I tried to convert the XEN Vm's which did not work at all (windows freaked out due to a config change) Then i reinstalled fresh on a brand new image under kvm. I used the guide on the wiki, I may not be missing anything but i sure hope i did lol.

[pyrater]

I recommend we get the wiki changed.... Bad advice on there to set Bus type to IDE.

 

"IDE - Slow Write in the Guest System

SCSI - Faster Write(as IDE) in Guest System

VIRTIO - Fastest Write (more that SCSI and IDE) in the Guest System, but only with extra Drivers."

 

https://kparal.wordpress.com/2012/09/12/kvm-disk-performance-ide-vs-virtio/

 

VirtIO is substantially faster for disk I/O operations. If you don’t use it, you should definitely consider it. If you run a lot of installation tests or other heavy disk operations like I do, it can be a pretty significant difference in performance.

[pyrater]

It will not let me just swtich to virtio only IDE and SATA (which breaks windows).... eitherway looks like ANOTHER reinstall is headed my way... whew

[pyrater]

Happy to report that using the virtio option over the IDE option has given me huge performance increases and has fixed my problem. =)