3engines_doc/docs/openstackcli/Use-backup-command-to-create-rotating-backups-of-virtual-machines-on-3Engines-Cloud.html.md

Use backup command to create rotating backups of virtual machines on 3Engines Cloud cloud🔗

Rotating backups in 3Engines refer to a backup strategy where older backups are automatically deleted after a predefined number of backups are created. This ensures that storage does not grow indefinitely while still maintaining a set number of recent backups for disaster recovery.

The rotating backup algorithm🔗

Creating rotating backups of virtual machines is a process comprising of the following steps:

Define the period of backups

Usually, daily, weekly, monthly or in any other time period.

Define rotation limit

How many backups to retain (we will refer to this number as maxN throughout this article).

Delete older backups

Once the limit is reached, start deleting the existing backups, usually the oldest one.

backup create vs. image create🔗

There are two ways of creating backups under 3Engines, using one of these two commands:

3Engines server backup create and 3Engines server image create

Here is how they compare:

Table 3 Comparison of Backup and Image Creation Commands🔗

Feature	3Engines server backup create	3Engines server image create
Association with VM	Associated using backup image property	Associated using backup name
Rotation support	Rotation with --backup-type and incremental backups	No built-in rotation support
Classification in Horizon	Marked as image	Marked as snapshot
Horizon Select Boot Source	Choose Instance Snapshot	Choose Image
Purpose	Primarily used for backups, can be rotated and managed	Creates a single VM snapshot without rotation
Incremental backup support	Yes, supports incremental backups	No, always creates a full snapshot
Multiple rotating schedules	No, only one	Yes (daily, weekly, monthly etc.)
Best usage scenario	Automated backup strategies with rotation	Capturing the current state of a VM for cloning or rollback
Can be scripted?	Yes	Yes

In this article we are going to use a 3Engines server backup create command under 3Engines to create rotating backups of virtual machines.

Prerequisites🔗

No. 1 Account

You need a 3Engines Cloud hosting account with access to the Horizon interface: https://horizon.3Engines.com

No. 2 VM which will be backed up

You need a virtual machine which will be backed up. If you don’t have one, you can create it by following one of these articles: