Re: KVM qcow2 perfomance

Qcow2 does lazy allocation. Try to write big file inside VM with dd (say 10GB), erase it and try again. May be lazy allocation works bad for your raid5e. 5 авг. 2017 г. 23:29 пользователь "Rodrigo Baldasso" < rodr...@loophost.com.br> написал: > Yes.. mounting an lvm volume inside the host works

Re: KVM qcow2 perfomance

Wow great explanation! Thank you Eric! On Sat, 5 Aug 2017 at 14:59 Eric Green wrote: > qcow2 performance has been historically bad regardless of the underlying > storage (it is an absolutely terrible storage format), which is why most > OpenStack Kilo and later

Re: KVM qcow2 perfomance

Rodrigo what's a version and system nfs server? Network performance between host pod and storage it's ok? On Sat, 5 Aug 2017 at 14:03 Ivan Kudryavtsev wrote: > Qcow2 does lazy allocation. Try to write big file inside VM with dd (say > 10GB), erase it and try again. May

Re: KVM qcow2 perfomance

qcow2 performance has been historically bad regardless of the underlying storage (it is an absolutely terrible storage format), which is why most OpenStack Kilo and later installations instead usually use managed LVM and present LVM volumes as iSCSI volumes to QEMU, because using raw LVM

Re: KVM qcow2 perfomance

Yes.. mounting an lvm volume inside the host works great, ~500Mb/s write speed.. inside the guest i'm using ext4 but the speed is aroung 30mb/s. - - - - - - - - - - - - - - - - - - - Rodrigo Baldasso - LHOST (51) 9 8419-9861 - - - - - - - - - - - - - - - - - - - On 05/08/2017 13:26:00, Ivan

Re: KVM qcow2 perfomance

Hi Ivan, In fact i'm testing using local storage.. but on NFS I was getting similar results also. Thanks! - - - - - - - - - - - - - - - - - - - Rodrigo Baldasso - LHOST (51) 9 8419-9861 - - - - - - - - - - - - - - - - - - - On 05/08/2017 13:03:24, Ivan Kudryavtsev

Re: KVM qcow2 perfomance

Rodrigo, is your fio testing shows great results? What filesystem you are using? KVM is known to work very bad over BTRFS. 5 авг. 2017 г. 23:16 пользователь "Rodrigo Baldasso" < rodr...@loophost.com.br> написал: Hi Ivan, In fact i'm testing using local storage.. but on NFS I was getting similar

Re: KVM qcow2 perfomance

Hi, I think Eric's comments are too tough. E.g. I have 11xSSD 1TB with linux soft raid 5 and Ext4 and it works like a charm without special tunning. Qcow2 also not so bad. LVM2 does it better of course (if not being snapshotted). Our users have different workloads and nobody claims disk

KVM qcow2 perfomance

Hi everyone, I'm having trouble to archive a good I/O rate using cloudstack qcow2 with any type of caching (or even disabled). We have some RAID-5e SSD arrays which give us a very good rates directly on the node/host, but on the guest the speed is terrible. Does anyone knows a

Re: KVM qcow2 perfomance

Hi, Rodrigo. It looks strange. Check your NFSconfiguration and network errors, loss. It should work great. 5 авг. 2017 г. 22:22 пользователь "Rodrigo Baldasso" < rodr...@loophost.com.br> написал: Hi everyone, I'm having trouble to archive a good I/O rate using cloudstack qcow2 with any type of