NFS on ZFS pure SSD pool

[Rick Macklem]

Sam Fourman Jr. wrote:
[lots of stuff snipped for brevity]
> root at students:/users # nfsstat -e -s
>
> Server Info:
>   Getattr   Setattr    Lookup  Readlink      Read     Write    Create
>  Remove
> 106273793   1417764  19593633     12021   2497674   7927757   1047249
>  772450
>    Rename      Link   Symlink     Mkdir     Rmdir   Readdir  RdirPlus
>  Access
>    319284       924     13813     63500     20980    526257         0
> 677005862
I didn't spot this when it first was posted, because of the wrap around.

That's a *lot* of Access operations, imho. Maybe tweaking the Mac OS X client
could reduce these?

I see there are a couple of options in their nfs.conf(5) file that might help?
nfs.client.access_cache_timeout
nfs.client.access_for_getattr

You could also look at their mount_nfs man page to see if there are other
settings for access related stuff.

As well, I'm wondering if the Macs may be doing Access ops like crazy because
they see that ACLs are enabled.
I think ZFS always have ACLs enabled, but you can change the line in
sys/fs/nfs/nfs_commonsubs.c
    int nfsrv_useacl = 1;
to
    int nfsrv_useacl = 0;
and then build/boot a new kernel on the server to disable them. (It isn't
a sysctl, because it normally depends on the server file system to say if
they are supported.)

Also, pull up a terminal window and do an "ls -l" on some directory, to make
sure everything isn;t owned by "nobody". If it is, the name/uid mapping for
NFSv4 isn;t working correctly.

Good luck with it, rick