Using snapshots on a VPS

Last updated 23rd September 2020

Objective

Creating a snapshot is a fast and simple way to secure a functioning system before making changes that might have undesired or unforeseen consequences, for example testing a new configuration or software. It does not, however, constitute a complete system backup strategy.

This guide explains the usage of snapshots for your OVHcloud VPS.

Requirements

• access to the OVHcloud Control Panel
• an OVHcloud VPS service already set up

Instructions

Log in to your OVHcloud Control Panel, navigate to the "Bare Metal Cloud" section, and select your server from the left-hand sidebar under Virtual Private Servers.

Step 1: Subscribing to the snapshot option

From the Home tab, scroll down to the box labelled Summary of options. Click on ... next to the option "Snapshot" and in the context menu click on Order.

In the next step, please take note of the pricing information, then click on Order. You will be guided through the order process and receive a confirmation email.

Step 2: Taking a snapshot

Once the option is enabled, click on ... next to the option "Snapshot" and in the context menu click Take a snapshot. Creating the snapshot might take a few minutes. Afterwards, the timestamp of the creation will appear in the Summary of options box.

Step 3: Deleting / restoring a snapshot

Since you can only have one snapshot activated at a time, the existing snapshot has to be deleted before creating a new one. Simply choose Delete the snapshot from the context menu.

If you are sure that you would like to reset your VPS to the status of the snapshot, click Restore the snapshot and confirm the restoration task in the popup window.

Please note that when you restore a VPS from a snapshot, the snapshot will be deleted.

Best practice for using snapshots

Configuring the QEMU agent on a VPS

Snapshots are instantaneous images of your running system ("live snapshot"). To ensure the availability of your system when the snapshot is created, the QEMU agent is used to prepare the filesystem for the process.

The required qemu-guest-agent is not installed by default on most distributions. Moreover, licensing restrictions may prevent OVHcloud from including it in the available OS images. Therefore, it is best practice to verify and install the agent in case it is not activated on your VPS. Connect to your VPS via SSH and follow the instructions below, according to your operating system.

Debian-based distributions (Debian, Ubuntu)

Use the following command to check whether the system is properly set up for snapshots:

$ file /dev/virtio-ports/org.qemu.guest_agent.0
/dev/virtio-ports/org.qemu.guest_agent.0: symbolic link to ../vport2p1

If the output is different ("No such file or directory"), install the latest package:

$ sudo apt-get update
$ sudo apt-get install qemu-guest-agent

Reboot the VPS:

$ sudo reboot

Check the service to ensure it is running:

$ sudo service qemu-guest-agent status

Redhat-based distributions (Centos, Fedora)

Use the following command to check whether the system is properly set up for snapshots:

$ file /dev/virtio-ports/org.qemu.guest_agent.0
/dev/virtio-ports/org.qemu.guest_agent.0: symbolic link to ../vport2p1

If the output is different ("No such file or directory"), install and enable the agent:

$ sudo yum install qemu-guest-agent
$ sudo chkconfig qemu-guest-agent on

Reboot the VPS:

$ sudo reboot

Check the agent and verify that it is running:

$ sudo service qemu-guest-agent status

Windows

You can install the agent via MSI file, available from the Fedora project website: https://fedorapeople.org/groups/virt/virtio-win/direct-downloads/latest-qemu-ga/

Verify that the service is running by using this powershell command:

PS C:\Users\Administrator> Get-Service QEMU-GA

Status   Name               DisplayName
------   ----               -----------
Running  QEMU-GA            QEMU Guest Agent

Go further

Using automated backups on a VPS

Join our community of users on https://community.ovh.com/en/.

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