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Re: [Xen-devel] domU oom -> xvda1 read-only without any notice?

To: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Subject: Re: [Xen-devel] domU oom -> xvda1 read-only without any notice?
From: Josip Rodin <joy@xxxxxxxxxxxxxx>
Date: Wed, 31 Mar 2010 09:49:50 +0200
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On Wed, Mar 31, 2010 at 08:43:07AM +0100, Keir Fraser wrote:
> On 31/03/2010 08:33, "Josip Rodin" <joy@xxxxxxxxxxxxxx> wrote:
> > % sudo mount -o remount,rw /
> > mount: block device /dev/xvda1 is write-protected, mounting read-only
> > 
> > There are no messages in the kernel log on either the .32 domU or the .26
> > dom0. What do I do, other than shutdown and re-create? How does one manually
> > 'talk' to blkback to see what's up?
> Blkback communicates this kind of info to blkfront via a node in xenstore
> named 'info'. Bit 2 of this numeric field indicates if a virtual disc is
> read-only. I think it's more likely that the domU has internally confused
> itself, rather than being told to mount read-only by dom0 -- the flags get
> probed when the virtual disc first appears, and I don't think would get
> probed again after that anyway without a full disc hot-unplug/replug.

OK, thanks, so is there any way I could examine xen-blkfront then? :)
I looked around and only found funny bits like:

% cat /sys/module/xen_blkfront/drivers/xen:vbd/vbd-51713/block/xvda1/ro

     2. That which causes joy or happiness.

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