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Instance recovery using qemu-nbd [closed]

asked 2015-03-18 16:44:03 -0500

rahulrajvn gravatar image

updated 2015-03-18 16:44:58 -0500

OS: Centos7

Openstack version : Juno

I was trying the recovery methods mentioned in docs.openstack.org/openstack-ops/content/maintenance.html

Mainly recovery of the Data in the instance Disk created @ /var/lib/nova/instances/xxxxxxx.instance-uuid-xxxxxx/disk

They are trying to mount the disk file using qemu-nbd command which gives me no result. When I try to modprobe the nbd module I get the following error.

modprobe: FATAL: Module nbd not found.

I was not able to find the package which gives the module.

any one have any idea regarding recovery of data from the data file of the instance.

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Closed for the following reason the question is answered, right answer was accepted by rahulrajvn
close date 2015-03-19 09:45:29.471499

2 answers

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answered 2015-03-19 01:57:27 -0500

dbaxps gravatar image

You may install libguestfs-tools on CentOS 7. Details of setup may be found here
http://bderzhavets.blogspot.com/2014/...

sudo yum install libguestfs-tools

Mount

$  guestfish --rw -a trusty-server-cloudimg-amd64-disk1.img

Welcome to guestfish, the guest filesystem shell for
editing virtual machine filesystems and disk images.

Type: 'help' for help on commands
      'man' to read the manual
      'quit' to quit the shell

> run
> list-filesystems
/dev/sda1: ext4
> mount /dev/sda1 /
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Hi , I needed to edit the disk file found @ /var/lib/nova/instances/xxxxxxx.instance-uuid-xxxxxx/disk. I tried guestfish for the same but it was not working listing any filesystem.

rahulrajvn gravatar imagerahulrajvn ( 2015-03-19 08:39:59 -0500 )edit

Its Working :)... Thanks

rahulrajvn gravatar imagerahulrajvn ( 2015-03-19 09:45:04 -0500 )edit

If you have an XFS image and you're trying to do a repair, don't forget to also install the libguestfs-xfs package.

ehayes gravatar imageehayes ( 2016-03-28 13:40:50 -0500 )edit
0

answered 2015-03-18 18:07:46 -0500

Ive tested this and it works just fine. Not sure what the package is called on Centos but on Ubuntu:

apt-cache search qemu-nbd

qemu-utils - QEMU utilities

Once you have that package or what ever is the equivalent for Centos you should be able to follow the procedure to recover data.

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Asked: 2015-03-18 16:44:03 -0500

Seen: 5,018 times

Last updated: Mar 19 '15