Date: Tue, 15 Oct 2013 21:00:23 -0600 From: Eric Browning <ericbrowning@skaggscatholiccenter.org> To: Rick Macklem <rmacklem@uoguelph.ca> Cc: FreeBSD FS <freebsd-fs@freebsd.org> Subject: Re: What is the NFS max thread limit Message-ID: <CAM=5oeCpiu=zG2PhNLu2Wf=xi7r8dUJNFqHOw48iRmzt7_aF7Q@mail.gmail.com> In-Reply-To: <744364739.41705471.1381876907892.JavaMail.root@uoguelph.ca> References: <CAM=5oeBt8o=4zshi46_H-s0TOnP2bnWq1N%2BdLmdQtb5c3HHx7w@mail.gmail.com> <744364739.41705471.1381876907892.JavaMail.root@uoguelph.ca>
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Here is the nfsstat -c output for one mac client for one day from one of my
busy workers. Are these numbers unreasonable? There are only 14 retries
which doesn't seem high so I think the network is ok. Any thoughts on
client side optimizations to reduce RPC load?
Client Info:
RPC Counts:
Getattr Setattr Lookup Readlink Read
Write
72725986 7586 56972 63 17082
22317
Create Remove Rename Link Symlink
Mkdir
4583 2041 3108 0 5
45
Rmdir Readdir RdirPlus Access Mknod
Fsstat
140 0 1106 49382068 0
26197
Fsinfo PathConf Commit
1 1 3650
RPC Info:
TimedOut Invalid X Replies Retries Requests
0 0 0 14 122252951
Cache Info:
Attr Hits Misses Lkup Hits Misses BioR Hits
Misses
761115632 3278207 110222766 53251 132864002
16282
BioW Hits Misses BioRLHits Misses BioD Hits
Misses
185211 22316 16004 63 12257339
5883
DirE Hits Misses
2990343 23
On Tue, Oct 15, 2013 at 4:41 PM, Rick Macklem <rmacklem@uoguelph.ca> wrote:
> Eric Browning wrote:
> > I'm currently still debugging slow NFS performance on mac clients.
> > Running
> > 9 stable with a mix of 200 Mac OS X 10.8, 10.7 and 10.6 clients.
> >
> > Periodically I get this error on the mac side:
> > automountd[1766]: set_and_fake_mapent_mntlevel: subdir=/Contents
> > error:
> > Contents not found in map=-fstab
> >
> > I'm wondering with 200 clients with five nfsiod threads (~1000 nfsiod
> > threads total) am I oversubscribing the nfs server? I can't seem to
> > configure any more than 256 threads (nfs_server_flags="-t -n 256").
> > When I
> > configure above 256 I get an error about it resetting to 4:
> >
> > Starting nfsd.
> > nfsd: nfsd count 512; reset to 4
> >
> > Tomorrow when all the mac clients have restarted I have changed their
> > nfsiod threads down to 1 each to see if this is indeed the issue.
> >
> Well, normally not all clients would be actively reading/writing files
> concurrently, so I wouldn't expect your load to need more than 256 nfsd
> threads. I also recall that you had a very large Access RPC load and
> Access RPCs are not done by nfsiod threads. (nfsiod threads only do
> readaheads and write behinds for buffer cache blocks of files.)
>
> However, if you do want to try more than 256 nfsd threads, you will
> need to edit nfsd.c and increase MAXNFSDCNT and then rebuild the nfsd
> daemon from these modified sources.
>
> I have no idea what causes the Mac OS X error, but you could try
> posting on one of the Apple mailing lists like
> darwin-kernel@lists.apple.com.
>
> rick
> ps: The nfsd.c in head/current/10.0 also has a "--maxthreads" option
> that I don't think is limited to MAXNFSDCNT from a glance at the code.
>
> > Thanks in advance,
> > --
> > Eric Browning
> > Systems Administrator
> > 801-984-7623
> >
> > Skaggs Catholic Center
> > Juan Diego Catholic High School
> > Saint John the Baptist Middle
> > Saint John the Baptist Elementary
> > _______________________________________________
> > freebsd-fs@freebsd.org mailing list
> > http://lists.freebsd.org/mailman/listinfo/freebsd-fs
> > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org"
> >
>
--
Eric Browning
Systems Administrator
801-984-7623
Skaggs Catholic Center
Juan Diego Catholic High School
Saint John the Baptist Middle
Saint John the Baptist Elementary
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