Use backup command to create rotating backups of virtual machines on 3Engines Cloud cloud[🔗](#use-backup-command-to-create-rotating-backups-of-virtual-machines-on-brand-name-cloud "Permalink to this headline")
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**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[🔗](#the-rotating-backup-algorithm "Permalink to this headline")
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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[🔗](#backup-create-vs-image-create "Permalink to this headline")
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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[🔗](#id1 "Permalink to this table")

| 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[🔗](#prerequisites "Permalink to this headline")
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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: