On Sun, 2011-09-11 at 01:18 +0200, Hans van Kranenburg wrote: > On 09/08/2011 07:12 PM, Hans van Kranenburg wrote: > > > > When putting disk/network load on one of our office servers, Xen/dom0 > > crashes. Triple ctrl-a does not react any more on serial console. > > > > We did not encounter this earlier on this particular piece of hardware, > > having tortured it some more in the past. A few days ago we set up drbd > > on this host [...] > > I've been searching some more, using snippets from the stacktrace. This > seems to be a known issue [1], [2] when using DRBD in combination with Xen. > > A workaround should be to set the option disable_sendpage when loading > the drbd module [3], [4].
Sounds similar to the NFS issue[0] which caused me to begin working on the SKB paged fragment destructor patches[1]. I just gave a talk about this problem at LPC last week[2] They are still a WIP but I hope to have them ready for Linux 3.3. I will include DRDB in my list of subsystems to consider. In the meantime disabling sendpage sounds like the best workaround. [0] http://marc.info/?l=linux-nfs&m=122424132729720&w=2 [1] http://marc.info/?l=linux-netdev&m=131072801125521&w=2 [2] http://linuxplumbersconf.org/2011/ocw/proposals/129 Ian. > > I remember reading about this some months ago. I've set this option on > both of the Xen/DRBD hosts at the office... > echo 1 > /sys/module/drbd/parameters/disable_sendpage > ... and added the "options drbd disable_sendpage=1" into > /etc/modprobe.d/drbd.conf > > Next week we'll see what happens when we put some stress on it. > > [1] http://www.gossamer-threads.com/lists/drbd/users/16962 > [2] > http://www.mentby.com/Group/drbd-user/kernel-panic-in-skbcopybits-squeeze.html > [3] http://www.gossamer-threads.com/lists/drbd/users/19980 > [4] http://www.drbd.org/users-guide/s-xen-drbd-mod-params.html > > -- > Hans van Kranenburg - System / Network Engineer > T +31 (0)10 2760434 | hans.van.kranenb...@mendix.com | www.mendix.com > > > -- Ian Campbell A hacker does for love what others would not do for money.
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