Re: Using disk image from NFS crashes kernel

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Mon, Oct 24, 2011 at 02:46:47PM +0200, Roger Pau Monné wrote:
> Hello,
> 
> I'm trying to use shared Xen disk images, over a NFS server. But when
> starting a guest that has the hard drive on an NFS share I get the
> following kernel crash:
> 
> balloon0 at xenbus0 id 0: Xen Balloon driver
> balloon0: current reservation: 524288 KiB
> balloon0: current reservation: 131072 pages => target: 131072 pages
> xbd backend: attach device vnd0d (size 10240000) for domain 2
> mapping kernel into physical memory
> about to get started...
> panic: kernel diagnostic assertion "pg != NULL" failed: file
> "/usr/src/sys/uvm/uvm_pager.c", line 489
> cpu0: Begin traceback...
> copyright() at ffffffff8097ceed
> uvm_pageratop() at netbsd:uvm_pageratop+0x7e
> nfs_doio() at netbsd:nfs_doio+0x1f9
> nfssvc_iod() at netbsd:nfssvc_iod+0x17b
> cpu0: End traceback...

please set ddb.onpanic to 1 and get a stack trace from here.
The traceback from panic doesn't look very reliable ...

> My kernel version is 5.99.52, and I'm running xen-unstable (although I
> think this bug is not related to xen itself).

It's probably not related to Xen, but I'd recommend trying a newer
-current kernel.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--