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* RE: starting domain when block device already mounted
@ 2005-01-16 22:49 James Harper
  2005-01-16 23:07 ` Anthony Liguori
  0 siblings, 1 reply; 8+ messages in thread
From: James Harper @ 2005-01-16 22:49 UTC (permalink / raw)
  To: Ian Pratt, xen-devel

My disks line is:

disk = [ 'phy:vg00/mail,0301,w', 'phy:vg00/mail-swap,0302,w' ]

The unpriv domain is up and running again, although I don't know what
damage has been done. /etc/passwd was missing though which is not a good
sign. I found it in /lost+found, but who knows what else is missing!

Thanks

James

> -----Original Message-----
> From: Ian Pratt [mailto:m+Ian.Pratt@cl.cam.ac.uk]
> Sent: Monday, 17 January 2005 09:34
> To: James Harper; xen-devel@lists.sourceforge.net
> Subject: RE: [Xen-devel] starting domain when block device already
mounted
> 
> > I just had a filesystem hosed in an unpriv domain (ext3
> > errors all over
> > the place), and then when I went to do a fsck on the block device it
> > told me it was already mounted, and sure enough, dom0 already had
the
> > device mounted. Would that cause a filesystem crash, or at
> > least errors?
> > Dom0 wasn't doing anything to the filesystem, and the unpriv
> > domain had
> > been up for a few weeks before this occurred.
> 
> Mounting an ext3 file system writeable in two domains is almost
certain
> to destroy it.
> 
> The tools try and prevent this. Was it a 'file:' vbd? There's
currently
> no safety checks for those, but there should be for physical partition
> and LVM volumes.
> 
> Ian
> 
> > Anyway, I've done this a few times before by mistake - made a few
> > changes to the unpriv domain's filesystem from dom0 and forgot to
> > unmount it before starting the domain. Is there any easy way
> > to get 'xm
> > create' to check before starting that none of the block devices it
is
> > about to export are in use? Such a thing would probably save me
> > countless headaches in the future! (or maybe it's been done
> > already? I'm
> > running 2.0.1)
> >
> > Thanks
> >
> > James
> >
> >
> > -------------------------------------------------------
> > The SF.Net email is sponsored by: Beat the post-holiday blues
> > Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek.
> > It's fun and FREE -- well,
almost....http://www.thinkgeek.com/sfshirt
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/xen-devel
> >



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^ permalink raw reply	[flat|nested] 8+ messages in thread
* RE: starting domain when block device already mounted
@ 2005-01-16 23:09 James Harper
  0 siblings, 0 replies; 8+ messages in thread
From: James Harper @ 2005-01-16 23:09 UTC (permalink / raw)
  To: James Harper, Ian Pratt, xen-devel

Oops. This machine is actually using something pre-2.0, so please ignore
everything I've said :) I'll complain again if it doesn't work when I
upgrade this machine.

Sorry about that.

James

> -----Original Message-----
> From: xen-devel-admin@lists.sourceforge.net [mailto:xen-devel-
> admin@lists.sourceforge.net] On Behalf Of James Harper
> Sent: Monday, 17 January 2005 09:49
> To: Ian Pratt; xen-devel@lists.sourceforge.net
> Subject: RE: [Xen-devel] starting domain when block device already
mounted
> 
> My disks line is:
> 
> disk = [ 'phy:vg00/mail,0301,w', 'phy:vg00/mail-swap,0302,w' ]
> 
> The unpriv domain is up and running again, although I don't know what
> damage has been done. /etc/passwd was missing though which is not a
good
> sign. I found it in /lost+found, but who knows what else is missing!
> 
> Thanks
> 
> James
> 
> > -----Original Message-----
> > From: Ian Pratt [mailto:m+Ian.Pratt@cl.cam.ac.uk]
> > Sent: Monday, 17 January 2005 09:34
> > To: James Harper; xen-devel@lists.sourceforge.net
> > Subject: RE: [Xen-devel] starting domain when block device already
> mounted
> >
> > > I just had a filesystem hosed in an unpriv domain (ext3
> > > errors all over
> > > the place), and then when I went to do a fsck on the block device
it
> > > told me it was already mounted, and sure enough, dom0 already had
> the
> > > device mounted. Would that cause a filesystem crash, or at
> > > least errors?
> > > Dom0 wasn't doing anything to the filesystem, and the unpriv
> > > domain had
> > > been up for a few weeks before this occurred.
> >
> > Mounting an ext3 file system writeable in two domains is almost
> certain
> > to destroy it.
> >
> > The tools try and prevent this. Was it a 'file:' vbd? There's
> currently
> > no safety checks for those, but there should be for physical
partition
> > and LVM volumes.
> >
> > Ian
> >
> > > Anyway, I've done this a few times before by mistake - made a few
> > > changes to the unpriv domain's filesystem from dom0 and forgot to
> > > unmount it before starting the domain. Is there any easy way
> > > to get 'xm
> > > create' to check before starting that none of the block devices it
> is
> > > about to export are in use? Such a thing would probably save me
> > > countless headaches in the future! (or maybe it's been done
> > > already? I'm
> > > running 2.0.1)
> > >
> > > Thanks
> > >
> > > James
> > >
> > >
> > > -------------------------------------------------------
> > > The SF.Net email is sponsored by: Beat the post-holiday blues
> > > Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek.
> > > It's fun and FREE -- well,
> almost....http://www.thinkgeek.com/sfshirt
> > > _______________________________________________
> > > Xen-devel mailing list
> > > Xen-devel@lists.sourceforge.net
> > > https://lists.sourceforge.net/lists/listinfo/xen-devel
> > >
> 
> 
> 
> -------------------------------------------------------
> The SF.Net email is sponsored by: Beat the post-holiday blues
> Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek.
> It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/xen-devel



-------------------------------------------------------
The SF.Net email is sponsored by: Beat the post-holiday blues
Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek.
It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt

^ permalink raw reply	[flat|nested] 8+ messages in thread
* RE: starting domain when block device already mounted
@ 2005-01-16 23:06 James Harper
  0 siblings, 0 replies; 8+ messages in thread
From: James Harper @ 2005-01-16 23:06 UTC (permalink / raw)
  To: Ian Pratt, xen-devel

Is it even present in 2.0.1? I can't see any reference to check_mounted
in xend/server/blkif.py, or any .py files there.

Thanks

James

> -----Original Message-----
> From: Ian Pratt [mailto:m+Ian.Pratt@cl.cam.ac.uk]
> Sent: Monday, 17 January 2005 10:01
> To: James Harper; xen-devel@lists.sourceforge.net
> Subject: RE: [Xen-devel] starting domain when block device already
mounted
> 
> > My disks line is:
> >
> > disk = [ 'phy:vg00/mail,0301,w', 'phy:vg00/mail-swap,0302,w' ]
> 
> The double-mount protection might need tweaking to work with LVM
volumes
> - I doubt its been tested.
> 
> Could you add some debugging to check_mounted in xend/server/blkif.py
?
> 
> Thanks,
> Ian



-------------------------------------------------------
The SF.Net email is sponsored by: Beat the post-holiday blues
Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek.
It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt

^ permalink raw reply	[flat|nested] 8+ messages in thread
* RE: starting domain when block device already mounted
@ 2005-01-16 23:00 Ian Pratt
  0 siblings, 0 replies; 8+ messages in thread
From: Ian Pratt @ 2005-01-16 23:00 UTC (permalink / raw)
  To: James Harper, xen-devel

> My disks line is:
> 
> disk = [ 'phy:vg00/mail,0301,w', 'phy:vg00/mail-swap,0302,w' ]

The double-mount protection might need tweaking to work with LVM volumes
- I doubt its been tested.

Could you add some debugging to check_mounted in xend/server/blkif.py ?

Thanks,
Ian


-------------------------------------------------------
The SF.Net email is sponsored by: Beat the post-holiday blues
Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek.
It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt

^ permalink raw reply	[flat|nested] 8+ messages in thread
* RE: starting domain when block device already mounted
@ 2005-01-16 22:34 Ian Pratt
  0 siblings, 0 replies; 8+ messages in thread
From: Ian Pratt @ 2005-01-16 22:34 UTC (permalink / raw)
  To: James Harper, xen-devel

> I just had a filesystem hosed in an unpriv domain (ext3 
> errors all over
> the place), and then when I went to do a fsck on the block device it
> told me it was already mounted, and sure enough, dom0 already had the
> device mounted. Would that cause a filesystem crash, or at 
> least errors?
> Dom0 wasn't doing anything to the filesystem, and the unpriv 
> domain had
> been up for a few weeks before this occurred.

Mounting an ext3 file system writeable in two domains is almost certain
to destroy it.

The tools try and prevent this. Was it a 'file:' vbd? There's currently
no safety checks for those, but there should be for physical partition
and LVM volumes.

Ian

> Anyway, I've done this a few times before by mistake - made a few
> changes to the unpriv domain's filesystem from dom0 and forgot to
> unmount it before starting the domain. Is there any easy way 
> to get 'xm
> create' to check before starting that none of the block devices it is
> about to export are in use? Such a thing would probably save me
> countless headaches in the future! (or maybe it's been done 
> already? I'm
> running 2.0.1)
> 
> Thanks
> 
> James
> 
> 
> -------------------------------------------------------
> The SF.Net email is sponsored by: Beat the post-holiday blues
> Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek.
> It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/xen-devel
> 


-------------------------------------------------------
The SF.Net email is sponsored by: Beat the post-holiday blues
Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek.
It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt

^ permalink raw reply	[flat|nested] 8+ messages in thread
* starting domain when block device already mounted
@ 2005-01-16 22:22 James Harper
  0 siblings, 0 replies; 8+ messages in thread
From: James Harper @ 2005-01-16 22:22 UTC (permalink / raw)
  To: xen-devel

I just had a filesystem hosed in an unpriv domain (ext3 errors all over
the place), and then when I went to do a fsck on the block device it
told me it was already mounted, and sure enough, dom0 already had the
device mounted. Would that cause a filesystem crash, or at least errors?
Dom0 wasn't doing anything to the filesystem, and the unpriv domain had
been up for a few weeks before this occurred.

Anyway, I've done this a few times before by mistake - made a few
changes to the unpriv domain's filesystem from dom0 and forgot to
unmount it before starting the domain. Is there any easy way to get 'xm
create' to check before starting that none of the block devices it is
about to export are in use? Such a thing would probably save me
countless headaches in the future! (or maybe it's been done already? I'm
running 2.0.1)

Thanks

James


-------------------------------------------------------
The SF.Net email is sponsored by: Beat the post-holiday blues
Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek.
It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt

^ permalink raw reply	[flat|nested] 8+ messages in thread
end of thread, other threads:[~2005-01-17  0:54 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2005-01-16 22:49 starting domain when block device already mounted James Harper
2005-01-16 23:07 ` Anthony Liguori
2005-01-17  0:54   ` Mark Williamson
  -- strict thread matches above, loose matches on Subject: below --
2005-01-16 23:09 James Harper
2005-01-16 23:06 James Harper
2005-01-16 23:00 Ian Pratt
2005-01-16 22:34 Ian Pratt
2005-01-16 22:22 James Harper

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