What's the safest way for backup and restore external snapshot using virsh libvirtd

Jason4Ever

Dears,

I've followed the following steps in order to get a snapshot of a running VM on my KVM, but actually i'm not sure if that the correct way or no :

/usr/bin/virsh snapshot-create-as \
--domain VM_NAME SNAPSHOT \
--diskspec vda,file=/var/lib/libvirt/images/snapshot.dsk ,snapshot=external \
--disk-only \
--atomic 

• then i edit the XML configuration in order to change the disk path to the original :

  virsh edit VM_NAME

replace:
/var/lib/libvirt/images/snapshot.dsk
with
/var/lib/libvirt/images/VM.dsk

• I delete the created snapshot:

/usr/bin/virsh snapshot-delete VM_NAME SNAPSHOT --metadata

• then i get a copy from the block disk:

/usr/bin/virsh -q blockcopy VM_NAME vda /backup/block.dsk --wait --verbose -
-shallow --pivot

• then :

/usr/bin/virsh blockcommit VM_NAME vda --active --verbose --pivot

• then i define the VM again using the its dump XML..

Are these steps correct for taking a safe backup for the instance ? although of the outputed files' sizes are small comparing to the original ?

and the most important part now is:

How to restore the snapshot or the block in case if i faced any problems ?
I tried to restore the block before using this command but it formatted the original disk and replaced with the small block that i backed up before which caused the VM to be lost :

# virsh stop VM_NAME

# qemu-img create \
-b /var/lib/libvirt/images/snapshot.dsk \
-f qcow2 \
var/lib/libvirt/images/VM.dsk

# virsh start VM_NAME

BharatB

lvcreate -s -L{size}{unit} -n {name} {path/to/lvm}

^ incase you're using a lvm

/bin/dd if="{/path/to/lvm}" of="{/path/to/backup.img}"

^ you create an image out of the lvm

Jason4Ever

@BharatB said:
lvcreate -s -L{size}{unit} -n {name} {path/to/lvm}

^ incase you're using a lvm

/bin/dd if="{/path/to/lvm}" of="{/path/to/backup.img}"

^ you create an image out of the lvm

Thanks dear . but i didn't understand the purpose of this commands ?

Are they for taking the backup or for restoring it ?

BharatB

For taking a snapshot and creating a img out of it consider it like a backup