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Date:      Tue, 19 Nov 2013 11:19:16 -0700
From:      Eric Browning <ericbrowning@skaggscatholiccenter.org>
To:        aurfalien <aurfalien@gmail.com>
Cc:        FreeBSD FS <freebsd-fs@freebsd.org>
Subject:   Re: Performance difference between UFS and ZFS with NFS
Message-ID:  <CAM=5oeAF2gfccrGNdbApUDpqRae4OQjZ7oaZZi4y1j%2BsF6PsTw@mail.gmail.com>
In-Reply-To: <9F76D61C-EFEB-44B3-9717-D0795789832D@gmail.com>
References:  <2103733116.16923158.1384866769683.JavaMail.root@uoguelph.ca> <9F76D61C-EFEB-44B3-9717-D0795789832D@gmail.com>

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Aurf,

I ran those two commands and it doesn't seem to have made a difference.
 Usage is still above 700% and it still takes 30s to list a directory.  The
time to list is proportional to the number of users logged in.  On UFS with
all students logged in and hammering away at their files there is no
noticeable speed decrease.


On Tue, Nov 19, 2013 at 11:12 AM, aurfalien <aurfalien@gmail.com> wrote:

>
> On Nov 19, 2013, at 5:12 AM, Rick Macklem wrote:
>
> > Eric Browning wrote:
> >> Some background:
> >> -Two identical servers, dual AMD Athlon 6220's 16 cores total @ 3Ghz,
> >> -64GB ram each server
> >> -Four Intel DC S3700 800GB SSDs for primary storage, each server.
> >> -FreeBSD 9 stable as of 902503
> >> -ZFS v28 and later updated to feature flags (v29?)
> >> -LSI 9200-8i controller
> >> -Intel I350T4 nic (only one port being used currently) using all four
> >> in
> >> LACP overtaxed the server's NFS queue from what we found out making
> >> the
> >> server basically unusable.
> >>
> >> There is definitely something going on between NFS and ZFS when used
> >> as a
> >> file server (random workload) for mac home directories.  They do not
> >> jive
> >> well at all and pretty much drag down these beefy servers and cause
> >> 20-30
> >> second delays when just attempting to list a directory on Mac 10.7,
> >> 10.8
> >> clients although throughput seems fast when copying files.
> >>
> >> This server's NFS was sitting north of 700% (7+ cores) all day long
> >> when
> >> using ZFSv28 raidz1. I have also tried stripe, compression on/off,
> >> sync
> >> enabled/disabled, and no dedup with 56GB of ram dedicated to ARC.
> >> I've
> >> tried just 100% stock settings in loader.conf and and some
> >> recommended
> >> tuning from various sources on the freebsd lists and other sites
> >> including
> >> the freebsd handbook.
> >>
> >> This is my mountpoint creation:
> >> zfs create -o mountpoint=/users -o sharenfs=on -o
> >> casesensitivity=insensitive -o aclmode=passthrough -o compression=lz4
> >> -o
> >> atime=off -o aclinherit=passthrough tank/users
> >>
> >> This last weekend I switched one of these servers over to a UFS raid
> >> 0
> >> setup and NFS now only eats about 36% of one core during the initial
> >> login
> >> phase of 150-ish users over about 10 minutes and sits under 1-3%
> >> during
> >> normal usage and directories all list instantly even when drilling
> >> down 10
> >> or so directories on the client's home files. The same NFS config on
> >> server
> >> and clients are still active.
> >>
> >> Right now I'm going to have to abandon ZFS until it works with NFS.
> >> I
> >> don't want to get into a finger pointing game, I'd just like to help
> >> get
> >> this fixed, I have one old i386 server I can try things out on if
> >> that
> >> helps and it's already on 9 stable and ZFS v28.
> >>
> > Btw, in previous discussions with Eric on this, he provided nfsstat
> > output that seemed to indicate most of his RPC load from the Macs
> > were Access and Getattr RPCs.
> >
> > I suspect the way ZFS handles VOP_ACCESSX() and VOP_GETATTR() is a
> > significant part of this issue. I know nothing about ZFS, but I believe
> > it does always have ACLs enabled and presumably needs to check the
> > ACL for each VOP_ACCESSX().
> >
> > Hopefully someone familiar with how ZFS handles VOP_ACCESSX() and
> > VOP_GETATTR() can look at these?
>
> Indeed.  However couldn't one simply disable ACL mode via;
>
> zfs set aclinherit=discard pool/dataset
> zfs set aclmode=discard pool/dataset
>
> Eric, mind setting these and see?
>
> Mid/late this week I'll be doing a rather large render farm test amongst
> our Mac fleet against ZFS.
>
> Will reply to this thread with outcome when I'm done.  Should be
> interesting.
>
> - aurf
>
> >
> > rick
> >
> >> Thanks,
> >> --
> >> 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"
> >>
> > _______________________________________________
> > 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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