From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (ext-mx13.extmail.prod.ext.phx2.redhat.com [10.5.110.18]) by int-mx12.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id p55Clp8O011068 for ; Sun, 5 Jun 2011 08:47:51 -0400 Received: from mail-pw0-f46.google.com (mail-pw0-f46.google.com [209.85.160.46]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p55ClooT009194 for ; Sun, 5 Jun 2011 08:47:50 -0400 Received: by pwi15 with SMTP id 15so2243343pwi.33 for ; Sun, 05 Jun 2011 05:47:50 -0700 (PDT) MIME-Version: 1.0 From: Andreas Schild Date: Sun, 5 Jun 2011 14:47:30 +0200 Message-ID: Content-Type: multipart/alternative; boundary=000e0cd2965eff09d504a4f6649f Subject: [linux-lvm] LVM label lost / system does not boot Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: To: linux-lvm@redhat.com --000e0cd2965eff09d504a4f6649f Content-Type: text/plain; charset=UTF-8 Hi The first part might sound like I am in the wrong group, but bear with me... (I probably am, but I googled up and down RAID and LVM lists and I am still stuck): I have a software RAID 5 with 4 disks and LVM on top. I had one volume group with two logical volumes (for root and data). I wanted to upgrade capacity and started by failing a drive, replacing it with a bigger one and let the RAID resync. Worked fine for the first disk. The second disk apparently worked (resynced, all looked good), but after a reboot the system hung. After some back and forth with superblocks (on the devices, never on the array) I was able to re-assemble the array clean. The system still does not reboot though: "Volume group "cmain" not found". I booted a live cd, assembled the array and did a pvck on the array (/dev/md0): "Could not find LVM label on /dev/md0" pvdisplay /dev/md0 results in: No physical volume label read from /dev/md0 Failed to read physical volume "/dev/md0" I do not have a backup of my /etc/ and therefore no details regarding the configuration of the LVM setup (yes, I know...) All I have of the broken system is the /boot partition with its content Several questions arise: - Is it possible to "reconstitute" the LVM with what I have? - Is the RAID array really ok, or is it possibly corrupt to begin with (and the reason no LVM labels are around)? - Should I try to reconstruct with pvcreate/vgcreate? (I shied away from any *create commands to not make things worse.) - If all is lost, what did I do wrong and what would I need to backup for a next time? Any ideas on how I could get the data back would greatly be appreciated. I am in way over my head, so if somebody knowledgeable tells me: "you lost, move on" would be bad, but at least would save me some time... Thanks, Andreas --000e0cd2965eff09d504a4f6649f Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Hi
The first part might sound like I am in the wrong group, but bear wi= th me...
(I probably am, but I googled up and down RAID and LVM l= ists and I am still =C2=A0stuck):
I have a=C2=A0software RAID 5 w= ith 4 disks and LVM on top. I had one volume group with two logical volumes= (for root and data).
I wanted to upgrade capacity and started by failing a drive, replacing= it with a bigger one and let the RAID resync. Worked fine for the first di= sk. The second disk apparently worked (resynced, all looked good), but afte= r a reboot the system hung.
After some back and forth with superblocks (on the devices, never on t= he array) I was able to re-assemble the array clean.
The system s= till does not reboot though: "Volume group "cmain" not found= ".

I booted a live cd, assembled the array and did a pvck = on the array (/dev/md0):
"Could not find LVM label on /dev/m= d0"
pvdisplay /dev/md0 results in:
=C2=A0 No = physical volume label read from /dev/md0
=C2=A0 Failed to read physical volume "/dev/md0"
=

I do not have a backup of my /etc/ and therefore no det= ails regarding the configuration of the LVM setup (yes, I know...)
All I have of the broken system is the /boot partition with its content

Several questions arise:
- Is it possible t= o "reconstitute" the LVM with what I have?
- Is the RAI= D array really ok, or is it possibly corrupt to begin with (and the reason = no LVM labels are around)?
- Should I try to reconstruct with pvcreate/vgcreate? (I shied away fr= om any *create commands to not make things worse.)
- If all is lo= st, what did I do wrong and what would I need to backup for a next time?

Any ideas on how I could get the data back would greatl= y be appreciated. I am in way over my head, so if somebody knowledgeable te= lls me: "you lost, move on" would be bad, but at least would save= me some time...

Thanks,
Andreas

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