RE: VERY slow NFS FC2 -> RH9

[Yang Xiao]

This maybe trivial, but try
http://nfs.sourceforge.net/nfs-howto/performance.html
> -----Original Message-----
> From: Gregory Gulik [mailto:[e-mail]] 
> Sent: Wednesday, June 30, 2004 1:27 PM
> To: For users of Fedora Core releases
> Subject: Re: VERY slow NFS FC2 -> RH9
>
> Ah, good point, but upon checking:
>
> Client:
> eth0: VIA VT6102 Rhine-II at 0xe8800000, 00:0c:6e:ec:87:0f, IRQ 10.
> eth0: MII PHY found at address 1, status 0x786d advertising 
> 01e1 Link 41e1.
> eth0: Setting full-duplex based on MII #1 link partner 
> capability of 41e1.
>
> Server:
> eth0: Intel(R) PRO/1000 Network Connection
> e1000: eth0 NIC Link is Up 100 Mbps Full Duplex
>
> I checked both switches and those links are both being indicated as 
> full-duplex.
>
> Here's another data point.  I used scp to copy the same 11MB 
> file that 
> that took 1.7 seconds.  That's really pointing at an NFS 
> problem rather 
> than a network problem.
>
> Yang Xiao wrote:
> > Hi,
> > Are you sure they are all running at 100/FULL? Try set both
>
> interfaces
> > to 100/FULL instead of AUTO. Yang
>
> -- 
> Greg Gulik                                 http://www.gulik.org/greg/
> greg @ gulik.org
>
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VERY slow NFS FC2 -> RH9

[Gregory Gulik]

Actually, I think I got it.  I removed the "sync" from the options and 
it sped up immediately.  The copy now took 2 seconds.

Hmm, I've been using that option for quite a while, probably at least 
since this client was on RH9 but only upon upgrading to FC2 did I find 
NFS performance to be this poor.

At least the problem is solved.  Thanks!

Yang Xiao wrote:
> This maybe trivial, but try
> http://nfs.sourceforge.net/nfs-howto/performance.html

VERY slow NFS FC2 -> RH9

[Tom Mitchell]

On Wed, Jun 30, 2004 at 12:47:07PM -0500, Gregory Gulik wrote:
> Date: Wed, 30 Jun 2004 12:47:07 -0500
> From: Gregory Gulik 
> To: For users of Fedora Core releases 
> Subject: Re: VERY slow NFS FC2 -> RH9
> Reply-To: For users of Fedora Core releases
>
> Actually, I think I got it.  I removed the "sync" from the options and 
> it sped up immediately.  The copy now took 2 seconds.
>
> Hmm, I've been using that option for quite a while, probably at least 
> since this client was on RH9 but only upon upgrading to FC2 did I find 
> NFS performance to be this poor.
>
> At least the problem is solved.  Thanks!

Well make sure to make a note in your system notebook about
turning off the sync option.

I have mixed opinions on the sync bit.  I have never found data
corruption issues that matter with modern uptimes but toggling this
bit is one of the classic benchmark tricks.  If specific data
integrity requirements justifies then you will want to set it back.
Some data base files need it.

Other tuning tricks have to do with matching read and write sizes to
the data chunkieness.  Also file locking...

I think you had a Rhine controller.  I have problems with my cheap
switch and this controller in full duplex.  Switching to half duplex
solved my packet loss and speeds then ran at 100BaseT(HD) speeds.  If
some of the NFS sync reply packets were getting lost then things slow
down a lot.  For me scp was ok, but rsync was not when I was running
in full duplex mode.

Anyhow when you see retransmit packets in tethereal or tcpdump output
between local systems switch from FD to HD and see if it helps.