[Pkg-xen-devel] Bug#674161: Bug#674161: xcp-xapi: 'the device disappeared from xenstore' message during vbd-plug (vm-start)

[Mike McClurg]

Hi George, thanks for testing XCP on Debian!

On Wed, May 23, 2012 at 3:07 PM, George Shuklin
<george.shuklin at gmail.com> wrote:
> Package: xcp-xapi
> Version: 1.3.2-6
> Severity: normal
> Tags: upstream
>
> vbd plug to PV domain cause following error:
>
> The server failed to handle your request, due to an internal error.  The given message may give details useful for debugging the problem.
> message: the device disappeared from xenstore (frontend (domid=4 | kind=vbd | devid=51760); backend (domid=0 | kind=vbd | devid=51760))

<snip>

> # xe sr-create type=file name-label=fileSR device-config:location=/mnt
> 319f3eaa-d1ba-a81d-acb3-493ecbdaab17

Here's the problem. The SR type "file" doesn't work the way you'd want
it to. It's actually the base class for the ext and NFS backends, and
isn't meant to be accessed directly. This class doesn't actually have
the create methods required to actually create the appropriate
directories necessary for a file-based SR.

Could you please try to reproduce this bug with a different backend?
NFS would probably be easiest. If the VBD plug happens on a different
SR type, then I'll consider this a bug.

Mike

PS: As an aside, it should be possible to manually create an SR of
this type yourself (or so the storage team leads me to believe). If
you create a fresh uuid using uuidgen, you can then create a directory
called /var/run/sm/<new uuid>, and then call 'xe sr-introduce
type=file uuid=<new uuid> name-label=name'. I haven't tried this yet,
but I'm about to.