A couple of quick suggestions:
1.) Turn on jumbo frames on the switch and the servers
2.) Turn atime off on the receiving (writing) end - the nfs server
Also, so I understand correctly, you've got 3 machines:
- data writer
- desktop
- nfs server
The desktop mounts an nfs volume. The data writer sends data to the
desktop, which writes it to the nfs volume.
If that's correct, then:
1.) Why not write directly to the nfs server and cut out the middle
man? This could be a matter of bad drivers on the desktop or whatever
else. You could accomplish this by having the data writing box send
data straight to the nfs server, or by mounting that nfs mount on the
data writer and having it write "locally" to that mount. You could
still mount that on the desktop for reading/ access/ editing.
2.) If you can't do that, why not write to local disk on the desktop
and then do an async move/ copy to the nfs volume?
I've always found NFS performance on linux to be lackluster, although
your numbers seem unusually bad.
Nicholas
On Thu, Sep 23, 2010 at 9:47 PM, Patrick Cable <p...@pcable.net> wrote:
> I have a device that sends out information at 4.7 Megabytes a second.
> I have a desktop that receives the data from this device that runs Red
> Hat Enterprise Linux 5.5. They are on the same switch, a 24-port
> Juniper EX2200.
>
> When I write the data to the desktop on the local filesystem, there's
> no dropped information. When I write the data to an NFS share, the
> device reports dropped packets.
>
> I have tried playing with the rsize/wsize NFS parameters (8192K seems
> to be the best value), and values in
> /proc/sys/net/core/{r,w}mem_{default,max} and increasing the NFS
> daemon count, as suggested by
> http://nfs.sourceforge.net/nfs-howto/ar01s05.html. Very similar
> results across the board.
>
> The NFS server also runs RHEL5.5. It's got 11 600gb 15k SAS drives in
> a hardware RAID6 array. Running 'iftop' on the machine during the data
> gathering operations, I'll see bursty traffic... that is to say,
> workstation -> NFS server traffic will be in the high 40mb/sec rate,
> then slow down, and once it slows down the device I refer to complains
> of dropped information then it'll speed up again.
>
> I find it hard to believe that a machine on the same (recent, gigabit)
> switch can't write out 4.7MB/sec. Am I wrong?
>
> Does anyone have any NFS or TCP tuning recommendations that may be a
> little more up to date than the NFS howto that was last updated in
> 2006? I'm really at a loss here.
>
> Thank you, more than a lot, in advance..
>
> - Pat
> _______________________________________________
> Tech mailing list
> Tech@lopsa.org
> http://lopsa.org/cgi-bin/mailman/listinfo/tech
> This list provided by the League of Professional System Administrators
> http://lopsa.org/
>
_______________________________________________
Tech mailing list
Tech@lopsa.org
http://lopsa.org/cgi-bin/mailman/listinfo/tech
This list provided by the League of Professional System Administrators
http://lopsa.org/
