FreeBSD 9.0 and NFS async

[Rick Macklem]

Johan Hendriks wrote:
> Rick Macklem schreef:
> > Johan Hendriks wrote:
> >> Hello all.
> >>
> >> I used to use async on my 8.x nfs servers!
> >> On the FreeBSD 9.0 server i can not do it through the old 8.x
> >> sysctl.
> >>
> >> Is there an other way to set async on FreeBSD 9.x
> >>
> > You have two choices:
> > 1 - Apply this patch to your NFS server's kernel sources and then
> > set
> >      vfs.nfsd.async=1
> >      http://people.freebsd.org/~rmacklem/async.patch
> >
> > 2 - switch to using the old server by setting
> >      oldnfs_server_enable="YES"
> >      in your /etc/rc.conf and then setting the sysctl.
> >
> > I'll assume that you realize that doing this violates the NFS RFCs
> > because
> > it runs your server in a way where there is a risk of data loss
> > (that the
> > client won't know to re-write) when the server crashes.
> >
> > rick
> >> regards,
> >> Johan Hendriks
> >> _______________________________________________
> >> freebsd-fs at freebsd.org mailing list
> >> http://lists.freebsd.org/mailman/listinfo/freebsd-fs
> >> To unsubscribe, send any mail to
> >> "freebsd-fs-unsubscribe at freebsd.org"
> Yes i do know the risk.
> 
> The thing is we want a dataset shared to a ESXi client using NFS.
> I use NFS for my normal usage, (sharing ports tree and so on.) but now
> we want to use it to share a ZFS dataset for a ESXi client.
> We use iscsi now, but this way we miss some zfs goodies. like
> snapshots(not a zvol) and most important, we can reach the files
> directly.
> 
> But with a virtual machine shared over NFS i get horrible performance.
> If i copy a file to whatever virtual machine from a windows client
> shared with iscsi , i get arround 80Mb per second (in the windows copy
> window) almost at a steady pace. we are really pleased with that. !!
> If i copy a virtual machine to the NFS share, fire it up, and do a
> file
> copy, it never gets higher than 50 Mb and it sometimes drop to 1 Mb
> then
> goes to 20 back to 10 and so on.
> Also the machines feels sluggish in performance.
> 
> Are there other less dangerous things i can try to boost performance?
> 
I don't use ZFS, but others have reported using a dedicated SSD that has
good write performance for the ZIL log in order to get better write
performance for ZFS.

> regards,
> Johan Hendriks