Ovirtsavior: a tool for backing-up your Ovirt VMs to local (or remote) storage

About

Ovirtsavior is an old fashioned backup/restore tool for the Ovirt virtualization platform. It can be used to:

• download the disks of a running VM to your local file system (backup mode).
• upload the disks of a previously backed up VM to a new Ovirt VM (restore mode).

You can use rclone to mount a remote directory to your local storage (Google Drive, etc). Use this with caution, it is probably much safer to save it to a local disc or NFS mount.

Ovirtsavior was created due to the support of the Study in Greece initiative.

Disclaimer

Use the software at your own risk. This has not been heavily tested in production environments. We suggest running the scripts on Ubuntu 20.04. It should work on Ovirt 4.3 and 4.4 engines.

VM backup & restore

The tool is used to backup and restore the discs.

• During the backup phase, the discs are downloaded in the working directory along with some rudimentary information regarding the VM parameters.
• In the restore phase, the disks are uploaded to the VM. You need to adjust the VM parameters including memory, CPU cores and also designate bootable disks.

Maybe in a future version we will include this as well.

Some information on the original VM are saved as well in a pickle file inside the VM folder.

Snapshots

All snapshot disks are downloaded during the backup phase in the working directory. However, during the restore phase, the disks are copied to a local temporary directory and the snapshots are collapsed. This practically means that you do not get any previous snapshots in the restored VMs. The reason for this is that we found there may be a bug in the Ovirt API not allowing you to upload intermittent disks with provisioned size lower than the actual size which prevented us from restoring the full snapshot chain. We plan to revisit this in the future.

Prequisites

You need to install qemu-img and python3-ovirt-engine-sdk4

On Ubuntu 20.04

apt update
apt-get --assume-yes install gcc \
    libxml2-dev \ 
    python3-dev \
    python3-pip \
    libcurl4-openssl-dev \
    libssl-dev \
    qemu-utils
pip3 install ovirt-engine-sdk-python

Modes

There are two modes you can use the ovirt-savior script: backup and restore. In backup mode, you download the VM disks to a local or remote folder. In restore mode, you create a VM using the OVirt API and then upload the discs. You have the option of collapsing the original VM's snapshots on the restored VM and this is probably your safest bet on getting the VM to work again. There seems to be a bug in OVirt that extends the snapshot disc image beyond its maximum size and although this does not affect the original running VM, it prohibits uploading the discs to the restored VMs.

Backup flow

The script creates a temporary snapshot of a running or powered off VM, downloads the disk chains contained in this snapshot and then removes the snapshot

Restore flow

A new VM is created with the same or different name and the disks are uploaded.

Usage

python3 ovirt-savior.py [mode] -s [config-file]

It may be a good idea to run this as root when using NFS shares. The mode option can be either backup or restore. The config-file specifies a configuration file that contains several options.

Sample configuration file

This is a sample configuration file that can be used for config-file

[CONNECTION]
ca_file : elovirt-pki-resource.cer
username : admin@internal
password : yourpassword
ovirt_url : https://elovirtengine.example.com/ovirt-engine/api

[RESTORATION]
storage_domain : vm_storage
cluster_name : Default
template : Blank

[DIRECTORIES]
local_directory : /tmp
working_directory : /backup

[SNAPSHOT]
backup_snapshot_description : SAVIOR_BACKUP_SNAPSHOT

[TRANSFER]
chunk_size : 1048576

[VM]
vm_name : test_for_backup
new_vm_name : test_for_restore

[MAIL]
smtp_sender : [email protected]
smtp_password : mailpassword
smtp_server : mail.example.com
smtp_port : 587
smtp_recipient : [email protected]

The following is a brief explanation of the parameters:

Connection section

• ca_file: the Ovirt engine certificate file. It can be downloaded on the OVirt engine web page.
• username: an Ovirt superadmin account username. You must include the domain (e.g. admin@internal).
• password: the password of the above account.
• ovirt_url: the URL of the Ovirt engine API, should be something in the line of https://elovirtengine.hua.gr/ovirt-engine/api

Directories section

• working_directory: the directory where the backups will be stored. The script creates a directory for each VM under working_directory
• local_directory: a directory where the discs are copied before uploaded to Ovirt. Use this in conjunction with copy_to_local and commit parameters in the restoration section.

Restoration section

This section describes the parameters used during the restoration process.

• storage_domain: the name of the storage domain where the VM will be restored (e.g. vm_storage).
• cluster_name : the name of the cluster where the VM will be restored. (e.g. Default)
• template : you could use this to define a template where the VM is based but since it is restored you should leave it equal to Blank.

Snapshot section

• backup_snapshot_description is the name of a temporary snapshot used to backup VMs (e.g. SAVIOR_BACKUP_SNAPSHOT)

Transfer section

• chunk_size : size of the blocks to be used in the disk transfers in bytes. Usually 1048576 is adequate.

Remote section

• mount_remote: if set to yes then a remote will be mounted using rclone.
• rclone_remote: is the name of the remote to be mounted before the backup or restore operation takes place. It will be unmounted once it is done.

VM section:

• vm_name : the name of the VM to be backed up or restored.
• new_vm_name : the new name for the restored VM. It can be different than vm_name.

Mail section

• smtp_sender : Account sending the job notifications
• smtp_password : Account password
• smtp_server : E-mail server address
• smtp_port : Port for communication (e.g. 587)
• smtp_recipient : Address receiving email notifications

Logging

The file savior.log located on the same folder as the script, contains a log of current backup and restore jobs. This log is send by e-mail according to the settings of the [MAIL] section.

Backup on NFS share

One common scenario is when you wish to backup your vm disks on an NFS share. On the NFS remote server you need to install:

apt update
apt install nfs-kernel-server
mkdir /var/nfs/backup -p
chown nobody:nogroup /var/nfs/backup

Create the file /etc/exports

/var/nfs/backup		10.100.59.154(rw,sync,no_subtree_check)

Then do:

ufw allow nfs
systemctl restart nfs-kernel-server

On the NFS client which will execute the ovirt backup scripts you need to install:

apt update
apt install nfs-common
sudo mount 195.130.90.2:/var/nfs/backup /nfs/backup
df -h

To mount the folder at boot append the following line to /etc/fstab

195.130.90.2:/var/nfs/backup    /nfs/backup     nfs  auto,nofail,noatime,nolock,intr,tcp,actimeo=1800 0 0