FreeBSD 9.0 and NFS async

[Peter Maloney]

On 12/13/2011 05:18 PM, 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.
>
That is interesting. I am doing the same thing (and settling for the
horrible 5-9MB/s writes right now with a decent ZIL that goes 65 MB/s
with any other NFS sync client). But without any NFS settings, I found I
can simply run:
    # zfs set sync=disabled tank/esxidatasetname
with the same file integrity sacrifice Rick mentions above.

I found that
    vfs.nfsd.async=1
doesn't actually do anything for me (8.2-STABLE Sept 29th).

> Are there other less dangerous things i can try to boost performance?
>
> regards,
> Johan Hendriks
>
>
>
>
>
>
>
> _______________________________________________
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> http://lists.freebsd.org/mailman/listinfo/freebsd-fs
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