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<p dir="auto">Regarding your last question. The boot error mostly happen when the disk has been modified (let's say power outage or shared-disk disconnect) while it was running, messing with the boot sectors.<br>
You can use the nova repair command to repair an instance, or you make snapshots regularly. Other option is to plug a recovery disk into the domain (using </p>
<blockquote>
<p dir="auto">virsh disk-attach</p>
</blockquote>
<p dir="auto">You can use the appropriate recovery systems depending on your images (GParted, DART, Ubuntu in recovery mode, etc...)</p>
<p dir="auto">On 12 Nov 2013, at 0:41, Razique Mahroua wrote:</p>
<blockquote>
<p dir="auto">Ok,<br>
in that case, use kpartx from the host against the disk image to discover partitions:<br>
kpartx -lv /var/lib/nova/[…]/disk<br>
to see if you find any partition</p>
<p dir="auto">You can as well try to recover it by using a live-cd.<br>
Can you show me the xml file of the domain?</p>
<p dir="auto">On 11 Nov 2013, at 23:59, Narayanan, Krishnaprasad <a href="mailto:narayana@uni-mainz.de">narayana@uni-mainz.de</a> wrote:</p>
<blockquote>
<p dir="auto">It’s a snapshot and the VM is trying to boot from the snapshot. It’s a linux image.<br>
From: Razique Mahroua [mailto:<a href="mailto:razique.mahroua@gmail.com">razique.mahroua@gmail.com</a>]<br>
Sent: Dienstag, 12. November 2013 08:53<br>
To: Narayanan, Krishnaprasad<br>
Cc: <a href="mailto:openstack@lists.openstack.org">openstack@lists.openstack.org</a><br>
Subject: Re: [Openstack] Recovering VMs in OPenStack ESSEX</p>
<p dir="auto">Is it a Linux or a W$ image?</p>
<p dir="auto">On 11 Nov 2013, at 23:29, Narayanan, Krishnaprasad <a href="mailto:narayana@uni-mainz.de">narayana@uni-mainz.de</a> wrote:</p>
<p dir="auto">It returned “No errors were found on the image”.</p>
<p dir="auto">From: Razique Mahroua [mailto:<a href="mailto:razique.mahroua@gmail.com">razique.mahroua@gmail.com</a>]<br>
Sent: Dienstag, 12. November 2013 08:22<br>
To: Narayanan, Krishnaprasad<br>
Cc: openstack<br>
Subject: Re: [Openstack] Recovering VMs in OPenStack ESSEX</p>
<p dir="auto">it’s a different problem now.<br>
Can you run :<br>
qemu-img check /var/lib/nova/[…]/disk</p>
<p dir="auto">thanks !</p>
<p dir="auto">On 11 Nov 2013, at 23:14, Narayanan, Krishnaprasad <a href="mailto:narayana@uni-mainz.de">narayana@uni-mainz.de</a> wrote:</p>
<p dir="auto">In the virsh list, I could see the instance status “running”. The GUI seems to be synchronized with the data from virsh. I don’t see an error now. In the VNC I could see an error message “Booting from floppy. Boot failed:could not read the boot disk. No bootable device”.<br>
From: Razique Mahroua [mailto:<a href="mailto:razique.mahroua@gmail.com">razique.mahroua@gmail.com</a>]<br>
Sent: Dienstag, 12. November 2013 08:12<br>
To: Narayanan, Krishnaprasad<br>
Cc: openstack<br>
Subject: Re: [Openstack] Recovering VMs in OPenStack ESSEX</p>
<p dir="auto">if you run:<br>
virsh list from the node, is the instance started?</p>
<p dir="auto">On 11 Nov 2013, at 22:56, Narayanan, Krishnaprasad <a href="mailto:narayana@uni-mainz.de">narayana@uni-mainz.de</a> wrote:</p>
<p dir="auto">I am able to start the VM in virsh. I got a new entry in the GUI but it said Error Spawning.<br>
From: Razique Mahroua [mailto:<a href="mailto:razique.mahroua@gmail.com">razique.mahroua@gmail.com</a>]<br>
Sent: Dienstag, 12. November 2013 07:31<br>
To: Narayanan, Krishnaprasad<br>
Cc: openstack<br>
Subject: Re: [Openstack] Recovering VMs in OPenStack ESSEX</p>
<p dir="auto">Yes, give the files to the nova.nova user:<br>
chown nova: /var/lib/nova/etc…</p>
<p dir="auto">On 11 Nov 2013, at 22:30, Narayanan, Krishnaprasad <a href="mailto:narayana@uni-mainz.de">narayana@uni-mainz.de</a> wrote:</p>
<p dir="auto">Do I have to change the ownership of these two files?</p>
<p dir="auto">From: Razique Mahroua [mailto:<a href="mailto:razique.mahroua@gmail.com">razique.mahroua@gmail.com</a>]<br>
Sent: Dienstag, 12. November 2013 07:29<br>
To: Narayanan, Krishnaprasad<br>
Cc: openstack<br>
Subject: Re: [Openstack] Recovering VMs in OPenStack ESSEX</p>
<p dir="auto">yup, should be good :</p>
<h1>root > qemu-img create -f qcow2 /var/lib/nova/instances/<em>base/fc1ff06266a986df09d4293a0be3dbb18884dc1d</em>0_None 0G</h1>
<p dir="auto">On 11 Nov 2013, at 22:28, Narayanan, Krishnaprasad <a href="mailto:narayana@uni-mainz.de">narayana@uni-mainz.de</a> wrote:</p>
<p dir="auto">I created the base image using the command below. I got a new error “Unable to allow access for disk path /var/lib/nova/instances/<em>base/ephemeral</em>0<em>20</em>None: No such file or directory”.</p>
<p dir="auto">Can I use a similar command to create the ephemeral disk?</p>
<p dir="auto">From: Razique Mahroua [mailto:<a href="mailto:razique.mahroua@gmail.com">razique.mahroua@gmail.com</a>]<br>
Sent: Dienstag, 12. November 2013 07:22<br>
To: Narayanan, Krishnaprasad<br>
Cc: openstack<br>
Subject: Re: [Openstack] Recovering VMs in OPenStack ESSEX</p>
<p dir="auto">it’s only an empty file provisioned according to your flavour.<br>
run this as root:</p>
<h1>root > qemu-img create -f qcow2 /var/lib/nova/instances/<em>base/fc1ff06266a986df09d4293a0be3dbb18884dc1d</em>20 20G</h1>
<p dir="auto">(pay attention to the last characters, I added the size “20G”)</p>
<p dir="auto">Razique</p>
<p dir="auto">On 11 Nov 2013, at 22:02, Narayanan, Krishnaprasad <a href="mailto:narayana@uni-mainz.de">narayana@uni-mainz.de</a> wrote:</p>
<p dir="auto">Oh I am sorry. I found the disk. You can ignore my previous email.</p>
<p dir="auto">I see a new error now<br>
“error: Failed to start domain instance-0000041c<br>
error: Unable to allow access for disk path /var/lib/nova/instances/<em>base/fc1ff06266a986df09d4293a0be3dbb18884dc1d</em>20: No such file or directory”</p>
<p dir="auto">This means that the base image is missing. Can I know is it possible to get this file fc1ff06266a986df09d4293a0be3dbb18884dc1d_20?<br>
From: Razique Mahroua [mailto:<a href="mailto:razique.mahroua@gmail.com">razique.mahroua@gmail.com</a>]<br>
Sent: Dienstag, 12. November 2013 06:49<br>
To: Narayanan, Krishnaprasad<br>
Cc: openstack<br>
Subject: Re: [Openstack] Recovering VMs in OPenStack ESSEX</p>
<p dir="auto">The _base directory contains only the base (or backing files) images, from which qemu-kvm creates the instance images.<br>
Everytime you spawn an instance, OpenStack creates a copy (not exactly a copy) of the image. It puts the base image inside _base (if it doesn’t exist) and create a light image that inherits the changes (the instance) inside /var/lib/nova/instance/instance-UUID/disk</p>
<p dir="auto">the disk is linked to that backing file.</p>
<p dir="auto">If you haven’t terminated it though, the file “disk” should be there. Is it an instance you’ve been able to use or a new one (meaning you never used it)?</p>
<p dir="auto">On 11 Nov 2013, at 21:45, Narayanan, Krishnaprasad <a href="mailto:narayana@uni-mainz.de">narayana@uni-mainz.de</a> wrote:</p>
<p dir="auto">I only rebooted the instance using the GUI. The instance was never terminated. Can I know what is present inside the _base folder in /var/lib/nova/instances?</p>
<p dir="auto">From: Razique Mahroua [mailto:<a href="mailto:razique.mahroua@gmail.com">razique.mahroua@gmail.com</a>]<br>
Sent: Dienstag, 12. November 2013 06:40<br>
To: Narayanan, Krishnaprasad<br>
Cc: openstack<br>
Subject: Re: [Openstack] Recovering VMs in OPenStack ESSEX</p>
<p dir="auto">That means the disk no longer exists. Did you terminated the instance?<br>
if so, then you won’t be able to retrieve it. Maybe you have backups?</p>
<p dir="auto">On 11 Nov 2013, at 21:38, Narayanan, Krishnaprasad <a href="mailto:narayana@uni-mainz.de">narayana@uni-mainz.de</a> wrote:</p>
<p dir="auto">I did as what you had suggested. I see an different error message now.</p>
<p dir="auto">“error: Failed to start domain instance-UUID<br>
error: Unable to allow access for disk path /var/lib/nova/instances/instance-UUID/disk: No such file or directory”</p>
<p dir="auto">This means that the disk is missing. Is it possible to create a disk?</p>
<p dir="auto">From: Razique Mahroua [mailto:<a href="mailto:razique.mahroua@gmail.com">razique.mahroua@gmail.com</a>]<br>
Sent: Dienstag, 12. November 2013 05:24<br>
To: Narayanan, Krishnaprasad<br>
Subject: Re: [Openstack] Recovering VMs in OPenStack ESSEX</p>
<p dir="auto">No,<br>
if you only need the file, create it manually using the prompt:<br>
root #> touch /var/lib/nova/instances/instance-UUID/console.log<br>
root # > chown nova. !$</p>
<p dir="auto">On 11 Nov 2013, at 20:02, Narayanan, Krishnaprasad <a href="mailto:narayana@uni-mainz.de">narayana@uni-mainz.de</a> wrote:</p>
<p dir="auto">If I get it correct, it has to be created from the virsh console. Can I know is the following procedure correct for the creation of the instance<br>
a) dumpxml the instance that is Shutoff<br>
b) create an instance using the output of a)</p>
<p dir="auto">If this is the case, it wouldn’t be recognized in OpenStack. Am I missing any link here?</p>
<p dir="auto">From: Razique Mahroua [mailto:<a href="mailto:razique.mahroua@gmail.com">razique.mahroua@gmail.com</a>]<br>
Sent: Montag, 11. November 2013 19:51<br>
To: Narayanan, Krishnaprasad<br>
Cc: <a href="mailto:openstack@lists.openstack.org">openstack@lists.openstack.org</a><br>
Subject: Re: [Openstack] Recovering VMs in OPenStack ESSEX</p>
<p dir="auto">Try to create it and chown it to nova:</p>
<p dir="auto">On Monday, November 11, 2013, Narayanan, Krishnaprasad wrote:<br>
Hi Razique,</p>
<p dir="auto">I executed the start command on the compute node using the domain name option. I got an error message saying that<br>
Error:“Failed to start domain instance-UUID”<br>
Error: Unable to precreate char dev file ‘/var/lib/nova/instances/ instance-UUID/console.log: No such file or directory.</p>
<p dir="auto">Can I get help to get rid of this problem?</p>
<p dir="auto">Thanks,<br>
Krishnaprasad<br>
From: Razique Mahroua [mailto:<a href="mailto:razique.mahroua@gmail.com">razique.mahroua@gmail.com</a>]<br>
Sent: Montag, 11. November 2013 17:22<br>
To: Narayanan, Krishnaprasad<br>
Cc: <a href="mailto:openstack@lists.openstack.org">openstack@lists.openstack.org</a><br>
Subject: Re: [Openstack] Recovering VMs in OPenStack ESSEX</p>
<p dir="auto">You have many solutions for that<br>
first try to power it on via<br>
$ virsh start<br>
and check /var/log/libvritd.log</p>
<p dir="auto">you can use kpartx to discover the partitions within the images, and use the different builtin system tools to fix the partitions<br>
fsck.ext4/ xfs_adm, etc…</p>
<p dir="auto">Razique</p>
<p dir="auto">On 11 Nov 2013, at 04:14, Narayanan, Krishnaprasad <a href="mailto:narayana@uni-mainz.de">narayana@uni-mainz.de</a> wrote:</p>
<p dir="auto">Hallo all,</p>
<p dir="auto">I looked in to forums about recovering VMs in OpenStack ESSEX. In the dashboard, I could see that the VMs status is “Hard rebooting” with power state Shutoff. In virsh, I could see that the state is Shutoff. The complete process is taking longer time to finish and I assume it is in a unrecoverable state. Can anybody help me in recovering the data on the VM and the VM itself?</p>
<p dir="auto">Thanks,<br>
Krishnaprasad</p>
<hr>
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</blockquote>
</blockquote>
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