..and the client is a RHEL 4 linux revision...

(sorry for any confusion)

On 5/5/06, Joe Little <jmlittle at gmail.com> wrote:
> Well, I used the dtrace script used here. The NFS implementation
> (server) is Solaris 11 B38, and the client and the RHEL linux
> revision, which doesn't have this problem going through other
> SAN-based NAS (NetApp, EMC, etc.. even iSCSI). I previously setup a
> Linux box as an iscsi initiator, XFS, and Linux's less than stellar
> kNFS server revision, and did not see this interaction. Thus, if there
> are any thread issues, its likely on Solaris' end or there is
> particularly bad interaction with linux clients if and only if the
> solaris backend is iSCSI. That latter doesn't make sense.
>
>
> On 5/5/06, Bart Smaalders <bart.smaalders at sun.com> wrote:
> > Joe Little wrote:
> > > Perhaps I'm finding bugs in the iscsi initiator.
> > >
> > > I can give the full dtrace reports (should I attach them?) but for now
> > > I'll give the three top segments. I did a mixed directory of only 1000
> > > items of around 3GB as a first test. The NFS->UFS test and the
> > > NFS->ZFS (local) were relatively fast, but the NFS->ZFS (over iscsi)
> > > was dog slow vs what that ZFS/iscsi link normally does.
> > >
> >
> > Could it be that your NFS implementation is single threaded on synch.
> > operations?
> >
> > In other words, the NFS implementation (or benchmark) is forcing lots
> > of synchronous IO operations that are single threaded.  If you're always
> > waiting for data to end up on the platter before issuing the next IO
> > request, this would kill performance.
> >
> > Perhaps a DTrace script to check workload concurrency is in order...
> >
> > - Bart
> >
> >
> >
> > --
> > Bart Smaalders                  Solaris Kernel Performance
> > barts at cyber.eng.sun.com         http://blogs.sun.com/barts
> >
>

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