General information

Immutable (WORM: Write-Once Read-Many) storage locations are meant to be written only once and can be read/accessed as many times as needed.

This is the perfect solution to protect your backups for specified amount of time against ransomware/attackers as, once written, this data cannot be altered or erased. This helps ensure that the data is kept consistent and safe for restores when required.

Configuration

VM Backup will only support backup Immutability with Versioning and Object Locking enabled on the following cloud locations:

• Azure
• Amazon S3

• Wasabi

It's important to note the following:

• the Offsite Retention period will automatically be the same as the Immutable period
  
  
• a VM assigned to one immutable offsite backup location can also be assigned to another non-immutable offsite location
  • the retention policy of both immutable and non-immutable offsite locations will be the same and match the immutable days to protect period as described above
    
    
    
    

Security

It is not possible to manually delete backup data stored in immutable backup locations for the duration of the Immutable policy - both via VM Backup or via the cloud provider console itself.

Naturally, this is a security benefit as you can have peace of mind that any data in the backup location will remain as originally intended and cannot simply be tampered with/deleted (always assuming it is within that protect period timespan).

Backup Speed

In order to implement the immutable backup functionality, the incremental backup process involves added operations when compared to regular Cloud Backups as aside from uploading the changed blocks, all the unchanged blocks that form part of that backup (and therefore are not uploaded thanks to our in-line deduplication algorithm) need to be updated to ensure their object lock also matches the desired immutable policy.

As a result, incremental backups to Immutable Cloud Storage Locations will take longer to complete than regular Cloud Locations.

Costs

Some additional costs are incurred when taking immutable backups due to additional calls required to maintain the immutable status of the required backup data.