Wesley, Try to disable compression on zfs fs On 07/28/2018 11:01 AM, Wesley Stewart wrote: Windows reportes about 500-600 MB/s over a 4GB file. However I believe I found the issue. My NFS backend is ZFS which is apparently notorious for horrible sync writes. https://forums.freenas.org/index.php?threads/sync-writes-or-why-is-my-esx... I will try an iSCSI target and see how that goes. On Sat, Jul 28, 2018, 1:49 PM Karli Sjöberg <karli@inparadise.se<mailto:karli@inparadise.se>> wrote: On Jul 28, 2018 19:30, Wesley Stewart <wstewart3@gmail.com<mailto:wstewart3@gmail.com>> wrote: I have added the "async" option to the "additional mount options" section. Transferring from my raided SSD mirrors is QUITE fast now. However, this might be confusing, but if I read/write to the nfs share at the same time performance plummits. So if I grab something from the SMB share over 10gb network and write this to my VM being hosted on the NFS share. Bad performance. Or If I copy and paste ISO from the VM to itself, horrible performance. If I grab a file from a VM on my raised SSD storage and copy it to my VM on the NFS Share, it has great performance (400+ MB/s) Not quite sure what's going on! However if I grab something from the 1gbps network everything seems okay. Or if I change the NFS Mount to the 1 gbps everything is okay. Any ideas? Let's start with expectations, shall we? 10Gb ~ 1 GB/s. So you read a file over SMB and write that to a VM hosted on NFS, so remote to remote. The absolute max for that transfer would be ~ 500 MB/s. What do you get? /K On Sat, Jul 28, 2018 at 3:02 AM Karli Sjöberg <karli@inparadise.se<mailto:karli@inparadise.se>> wrote: On Jul 28, 2018 01:01, Wesley Stewart <wstewart3@gmail.com<mailto:wstewart3@gmail.com>> wrote: I currently have a NFS server with decent speeds. I get about 200MB/s write and 400+ MB/s read. My single node oVirt host has a mirrored SSD store for my Windows 10 VM, and I have about 3-5 VMs running on the NFS data store. However, VM/s on the NFS datastore are SLOW. They can write to their own disk around 10-50 MB/s. However a VM on the mirrored SSD drives can get 150-250 MB/s transfer speed from the same NFS storage (Through NFS mounts). Does anyone have any suggestions on what I could try to speed up the NFS storage for the VMs? My single node ovirt box has a 1ft Cat6 crossover cable plugged directly into my NFS servers 10GB port. Thanks! _______________________________________________ Users mailing list -- users@ovirt.org<mailto:users@ovirt.org> To unsubscribe send an email to users-leave@ovirt.org<mailto:users-leave@ovirt.org> Privacy Statement: https://www.ovirt.org/site/privacy-policy/<https://eur01.safelinks.pro... oVirt Code of Conduct: https://www.ovirt.org/community/about/community-guidelines/<https://eu... List Archives: https://lists.ovirt.org/archives/list/users@ovirt.org/message/OFTRL5QWQS5... It may be because of how oVirt mounts them, much more carefully, than Linux does by default. If I am not mistaken, oVirt mounts the NFS shares with 'sync', whereas a standard 'mount' with no options gets you 'async'. The difference in performance is huge, but for a reason; it's unsafe in case of a power failure. That may explain things. /K _______________________________________________ Users mailing list -- users@ovirt.org<mailto:users@ovirt.org> To unsubscribe send an email to users-leave@ovirt.org<mailto:users-leave@ovirt.org> Privacy Statement: https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.ovi... oVirt Code of Conduct: https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.ovi... List Archives: https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.o...