Re: [vfio-users] vm lags/pauses when IO overloaded on host

2016-07-25 Thread Jiri 'Ghormoon' Novak
Hi, it still sound to me like some qemu misconfiguration, it doesn't seem normal that the VM pauses and then fast-forwards the paused time. (eg. if you watch spinning circle that does 1spin/s, when doing IO heavy stuff, it will hang the machine completely for eg. 10s, you can't even move mouse or

Re: [vfio-users] vm lags/pauses when IO overloaded on host

2016-07-20 Thread Samuel Holland
On 07/20/2016 02:41 AM, Marcin Falkiewicz wrote: ZFS's zvol is really bad for virtual disk backend when you have only few HDDs (or even SSDs) - I had a lot problems with latency and throughput on my 2-disk mirrored testbench. Hard to tell if it's ZFS itself, ZoL or just not enough disks and slow

Re: [vfio-users] vm lags/pauses when IO overloaded on host

2016-07-20 Thread Marcin Falkiewicz
ZFS's zvol is really bad for virtual disk backend when you have only few HDDs (or even SSDs) - I had a lot problems with latency and throughput on my 2-disk mirrored testbench. Hard to tell if it's ZFS itself, ZoL or just not enough disks and slow controller. On the other hand, LVM runs great o

[vfio-users] vm lags/pauses when IO overloaded on host

2016-07-19 Thread Jiri 'Ghormoon' Novak
Hi, for quite long time, I've got an issue with my drives configuration on my VMs that do vga passthrough (but I think it's unrelated to passthrough as they would lag without passthrough too). the config is -drive file=/dev/something,if=none,id=drive-virtio-disk0,format=raw,cache=none,aio=native