RE: Problem Growing Raid 5 Array - Help Needed!

["Jeremy Leigh" <jeremy.leigh@gmail.com>]

Hi David, you are right, thankyou!
I have now:

[root@FileServer ~]#pvresize /dev/md0

And then from system-config-lvm I have selected 'Use Remaining' space on the
logical volume.

All done. Good thing LVM keeps a lock on the device ;) 

No doubt someone thought there would be users like me :D


-----Original Message-----
From: David Greaves [mailto:david@dgreaves.com] 
Sent: Wednesday, 4 June 2008 2:51 AM
To: Jeremy Leigh
Cc: linux-raid@vger.kernel.org
Subject: Re: Problem Growing Raid 5 Array - Help Needed!

Jeremy Leigh wrote:
> Hi David,
> Mount works fine for the LVM volume sitting on /dev/md0
> [root@FileServer ~]# mount /dev/LVMRAID/LV0 /home

Ah...

lvm is holding /dev/md0 open.

lvm is layered on top of, and uses, md - just like md uses your hard disks.

Try:
  /etc/init.d/lvm2 stop

That should do it.


> Finally, I can give you output of mdadm --detail, but to be honest, I
don't
> know what else I can do... This is really frustrating.
It would be nice if something told you what was holding the lock.
I occasionally forget on the server that uses lvm.

> These commands are being run from root.
>
> [root@FileServer ~]# fsck /dev/md0
Yeah - that's a bad idea!!!
your filesystem lives on /dev/LVMRAID/LV0
  fsck /dev/LVMRAID/LV0

If you had been really unlucky, fsck could have found a superblock and
started
scribbling all over your filesystem with potentially devastating results!
Always run filesystem tools on the device holding the filesystem, rather
than
some random component ;)

and similartly
> [root@FileServer ~]# resize2fs /dev/md0
resize2fs /dev/LVMRAID/LV0

HTH

David