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-esxi-nfs-so-slow-and-why-is-iscsi-faster.12506/ I will try an iSCSI target and see how that goes. On Sat, Jul 28, 2018, 1:49 PM Karli Sjöberg <ka...@inparadise.se> wrote: > > > On Jul 28, 2018 19:30, Wesley Stewart <wstewa...@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 <ka...@inparadise.se> wrote: > > > > On Jul 28, 2018 01:01, Wesley Stewart <wstewa...@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 > To unsubscribe send an email to users-le...@ovirt.org > Privacy Statement: https://www.ovirt.org/site/privacy-policy/ > oVirt Code of Conduct: > https://www.ovirt.org/community/about/community-guidelines/ > List Archives: > https://lists.ovirt.org/archives/list/users@ovirt.org/message/OFTRL5QWQS5SVL23YFZ5KBFBN3F6THQ3/ > > > 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 > > > >
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