This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


[Xen-users] Xen/Gentoo/NFS=really slow & nfs timeout

To: xen-users@xxxxxxxxxxxxxxxxxxx
Subject: [Xen-users] Xen/Gentoo/NFS=really slow & nfs timeout
From: Adam Carheden <adam.carheden@xxxxxxxxx>
Date: Fri, 23 Dec 2005 18:08:30 -0700
Delivery-date: Sat, 24 Dec 2005 01:11:57 +0000
Domainkey-signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition; b=MGjs3alcVGKTgYlUhXbgs0DSjsk5TsRWfXgf/NQ1wA6xzVmx62GkcsLYnBuoq5Fwx3P8WjAB6YpH1FcSoFqR31e8qI1lzfmP4+IeRNv9TboocZezS38+OVGa8QP9Fipn5l5JQBGFuarvTC3rlfzOXRzU2VtZ0eUaVaUr6DXBOL4=
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
List-help: <mailto:xen-users-request@lists.xensource.com?subject=help>
List-id: Xen user discussion <xen-users.lists.xensource.com>
List-post: <mailto:xen-users@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=unsubscribe>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
I've got Gentoo Linux running as both DOM0 and DOMU on a few Xen
boxes, but the NFS client with this configuration is really slow
because it keeps timeing out. The following is true:

Gentoo (No Xen) = FAST
SuSE (No Xen) = FAST
Gentoo (DOM0) = SLOW
Gentoo (DOMU) = SLOW (Gentoo is DOM0)
SuSE (DOMU) = FAST (Gentoo is DOM0)

I've tried all configurations with both a Gentoo and SuSE NFS server
(No XEN) with the same results. I can speed things up by setting rsize
and wsize to 16384, but it's still much slower than SuSE DOMU or
non-xen (Gentoo or SuSE).

Gentoo (No Xen): 231.7 MB/s (95 MB file)
SuSE DOMU (Gentoo DOM0): 339 MB/s (95 MB file)
Gentoo DOM0: .035 MB/s (1MB file, rsize/wsize=16384)

What's more, I get slower speeds on SuSE DOMU when Gentoo DOM0 is
accessing NFS, so I'm guessing it's generating network traffic to slow
stuff down.

And the answers to the obvious questions...
- I can duplicate the problem on two differen Gentoo/Xen boxes (one is
pentium$, the other is AMD64).
- Other other network operations work about the same on various
configurations, though SCP only gives me about 10MB/s on SuSE or
Gentoo uner Xen while it gives me about 22MB/s on Gentoo without Xen.
- I'm using bridging to share the network connection.
- I get "nfs: server <my-nfs-server> not responding, timed out" in
dmesg in Gentoo under Xen, but not on SuSE/Xen or Gentoo/No Xen.

Any ideas why nfs is timeing out under xen and/or how to fix it?

Adam Carheden

Xen-users mailing list

<Prev in Thread] Current Thread [Next in Thread>
  • [Xen-users] Xen/Gentoo/NFS=really slow & nfs timeout, Adam Carheden <=