From: Alan Post <adp@prgmr.com>
To: Benjamin Coddington <bcodding@redhat.com>
Cc: linux-nfs <linux-nfs@vger.kernel.org>
Subject: Re: User process NFS write hang in wait_on_commit with kworker
Date: Tue, 18 Jun 2019 18:07:46 -0600 [thread overview]
Message-ID: <20190619000746.GT4158@turtle.email> (raw)
In-Reply-To: <6DE07E49-D450-4BF7-BC61-0973A14CD81B@redhat.com>
On Tue, Jun 18, 2019 at 11:29:16AM -0400, Benjamin Coddington wrote:
> I think that your transport or NFS server is dropping the response to an
> RPC. The NFS client will not retransmit on an established connection.
>
> What server are you using? Any middle boxes on the network that could be
> transparently dropping transmissions (less likely, but I have seen them)?
>
I've found 8 separate NFS client hangs of the sort I reported here,
and in all cases the same NFS server was involved: an Ubuntu Trusty
system running 4.4.0. I've been upgrading all of these NFS servers,
haven't done this one yet--the complicity of NFS hangs I've been
seeing have slowed me down.
Of the 8 NFS clients with a hang to this server, about half are in
the same computer room where packets only transit rack switches, with
the other half also going through a computer room router.
I see positive dropped and overrun packet counts on the NFS server
interface, along with a similar magnitude of pause counts on the
switch port for the NFS server. Given the occurences of this issue
only this rack switch and a redundant pair of top-of-rack switches in
the rack with the NFS server are in-common between all 8 NFS clients
with write hangs.
-A
--
Alan Post | Xen VPS hosting for the technically adept
PO Box 61688 | Sunnyvale, CA 94088-1681 | https://prgmr.com/
email: adp@prgmr.com
next prev parent reply other threads:[~2019-06-19 0:06 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-18 0:06 User process NFS write hang in wait_on_commit with kworker Alan Post
2019-06-18 15:29 ` Benjamin Coddington
2019-06-19 0:07 ` Alan Post [this message]
2019-06-19 12:38 ` Benjamin Coddington
2019-06-21 20:47 ` Alan Post
2019-06-28 18:33 ` Alan Post
2019-07-02 9:55 ` Benjamin Coddington
2019-07-03 21:32 ` Alan Post
2019-07-05 23:53 ` Tom Talpey
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