Linux KVM – Change libvirt VM image store path – Part 10

In KVM , VM images are stored in /var/lib/libvirt/images directory by default.  There might be the space limitation since /var filesystem lives under root-vg. In KVM virtualization, everyone would prefer to store VM images in central repository to migrate running VM from one hypervisor to another.  In that case, you need to change the default path for the libvirt images or  you need to mount the volume or NFS share on “/var/lib/libvirt/images” . In this article, we will see that how to modify the default libvirt images path to desired one. In KVM terminology , we will call it  as “storage pool”.

 

Note: This activity has been  performed on non-selinux Node. If SELINUX is enabled, then you need to modify the context for new storage path accordingly .

[root@UA-HA ~]# getenforce
Disabled
[root@UA-HA ~]#

 

1.Login to the KVM hypervisor host and stop all the running VM’s.

[root@UA-HA kvmpool]# virsh shutdown UAKVM2
[root@UA-HA kvmpool]#
[root@UA-HA ~]# virsh list --all
 Id    Name                           State
----------------------------------------------------
 -     UAKVM2                         shut off

[root@UA-HA ~]#

 

2.List the storage pool.

[root@UA-HA ~]# virsh pool-list
 Name                 State      Autostart
-------------------------------------------
 default              active     yes

[root@UA-HA ~]#

 

3.View the storage pool information.

[root@UA-HA ~]# virsh pool-info default
Name:           default
UUID:           3599dd8a-edef-4c00-9ff5-6d880f1ecb8b
State:          running
Persistent:     yes
Autostart:      yes
Capacity:       17.50 GiB
Allocation:     7.67 GiB
Available:      9.82 GiB

[root@UA-HA ~]#

 

4. Check the existing storage pool path. (Ignore the syntax)

[root@UA-HA ~]# virsh pool-dumpxml default |grep -i path
    path-/var/lib/libvirt/images-/path
[root@UA-HA ~]#

 

5. Verify that what are the existing VM images are stored on the default path.

[root@UA-HA ~]# virsh vol-list default |grep "/var/lib/libvirt/images"
 UAKVM2.qcow2         /var/lib/libvirt/images/UAKVM2.qcow2
[root@UA-HA ~]#
[root@UA-HA ~]# virsh vol-list default
 Name                 Path
------------------------------------------------------------------------------
 UAKVM2.qcow2         /var/lib/libvirt/images/UAKVM2.qcow2

[root@UA-HA ~]#

 

6.Stop the storage pool.

[root@UA-HA ~]# virsh pool-destroy default
Pool default destroyed

[root@UA-HA ~]#

 

7.Edit the default pool configuration.

 

8.Start the storage pool.

[root@UA-HA ~]# virsh pool-start default
Pool default started

[root@UA-HA ~]#

 

9.Verify the storage pool path. (Ignore the syntax)

[root@UA-HA ~]# virsh pool-dumpxml default |grep -i path
    path  /kvmpool path
[root@UA-HA ~]#

 

10. Move the VM images from old path to new Path.

[root@UA-HA ~]# mv /var/lib/libvirt/images/UAKVM2.qcow2 /kvmpool/
[root@UA-HA ~]#

 

11. Edit the VM configuration file to update the new storage pool path. (Ignore syntax)

 source file='/kvmpool/UAKVM2.qcow2'

 

12.Start the KVM guest.

[root@UA-HA kvmpool]# virsh start UAKVM2
Domain UAKVM2 started

[root@UA-HA kvmpool]#

 

If you get error like below,

” error: Failed to start domain XXXXX
error: unsupported configuration: Unable to find security driver for model selinux ”

Edit the VM configuration file and remove “selinux” line from the XML file (In Bottom) & try to start the VM.

# virsh edit UAKVM2
...................

seclabel type='dynamic' model='selinux' relabel='yes';/seclabel   ----> Remove this line .

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