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Date:      Thu, 18 Oct 2012 18:37:40 +0200
From:      "Ronald Klop" <ronald-freebsd8@klop.yi.org>
To:        freebsd-fs@freebsd.org
Subject:   Re: Poor throughput using new NFS client (9.0) vs. old (8.2/9.0)
Message-ID:  <op.wmdu42x88527sy@ronaldradial.versatec.local>
In-Reply-To: <CAFevjsthqegWv_GXVXceabwYf9urKZ7kEW2qQw7DSQpC7Hv0BA@mail.gmail.com>
References:  <CAFevjsthqegWv_GXVXceabwYf9urKZ7kEW2qQw7DSQpC7Hv0BA@mail.gmail.com>

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On Thu, 18 Oct 2012 18:16:16 +0200, Thomas Johnson <tom@claimlynx.com>  
wrote:

> We recently upgraded a number of hosts from FreeBSD 8.2 to 9.0. Almost
> immediately, we received reports from users of poor performance. The
> upgraded hosts are PXE-booted, with an NFS-mounted root. Additionally,  
> they
> mount a number of other NFS shares, which is where our users work from.
> After a week of tweaking rsize/wsize/readahead parameters (per guidance),
> it finally occurred to me that 9.0 defaults to the new NFS client and
> server. I remounted the user shares using the oldnfs file type, and users
> reported that performance returned to its expected level.
>
> This is obviously a workaround, rather than a solution. We would prefer  
> to
> get our hosts using the newnfs client, since presumably oldnfs will be
> deprecated at some point in the future. Is there some change that we  
> should
> have made to our NFS configuration with the upgrade to 9.0, or is it
> possible that our workload is exposing some deficiency with newnfs? We  
> tend
> to deal with a huge number of tiny files (several KB in size). The NFS
> server has been running 9.0 for some time (prior to the client upgrade)
> without any issue. NFS is served from a zpool, backed by a Dell MD3000,
> populated with 15k SAS disks. Clients and server are connected with Gig-E
> links. The general hardware configuration has not changed in nearly 3  
> years.
>
> As an example of the performance difference, here is some of the testing  
> I
> did while troubleshooting. Given a directory containing 5671 zip files,
> with an average size of 15KB. I append all files to an existing zip file.
> Using the newnfs mount, I found that this operation generally takes ~30
> seconds (wall time). Switching the mount to oldnfs resulted in the same
> operation taking ~10 seconds.
>
> tom@test-1:/test-> ls 53*zip | wc -l
>     5671
> tom@test-1:/test-> ll -h BIG*
> -rw-rw-r--  1 tom      claimlynx   8.9M Oct 17 14:06 BIGGER_PILE_1.zip
> tom@test-1:/test-> time zip BIGGER_PILE_1.zip 53*.zip
> 0.646u 0.826s 0:51.01 2.8%    199+2227k 0+2769io 0pf+0w
> ...reset and repeat...
> 0.501u 0.629s 0:30.49 3.6%    208+2319k 0+2772io 0pf+0w
> ...reset and repeat...
> 0.601u 0.522s 0:32.37 3.4%    220+2406k 0+2771io 0pf+0w
>
> tom@test-1:/-> cd /
> tom@test-1:/-> sudo umount /test
> tom@test-1:/-> sudo mount -t oldnfs -o rw server:/array/test /test
> tom@test-1:/-> mount | grep test
> server:/array/test on /test (oldnfs)
> tom@test-1:/-> cd /test
> ...reset and repeat...
> 0.470u 0.903s 0:13.09 10.4%    203+2229k 0+5107io 0pf+0w
> ...reset and repeat...
> 0.547u 0.640s 0:08.65 13.6%    231+2493k 0+5086io 0pf+0w
> tom@test-1:/test-> ll -h BIG*
> -rw-rw-r--  1 tom      claimlynx    92M Oct 17 14:14 BIGGER_PILE_1.zip
>
> Thanks!
>


You might find this thread from today interesting.
http://lists.freebsd.org/pipermail/freebsd-fs/2012-October/015441.html

Ronald.



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