Skip to main content

What backups can I safley delete

Thread solved

 Acronis 2021 

 

I have computer set to back up once per day

After the first full copy others are incrimental.  Can I retain first full backup and last incrimental and delete the others 

 

 

0 Users found this helpful

After the first full copy others are incrimental.  Can I retain first full backup and last incrimental and delete the others 

Simple answer to the above is a definite NO!  If you delete any incremental backup files before the last one created then the whole incremental set is of zero value as each new incremental builds on the changes made since the previous backup was created.

You could delete all incrementals leaving only the full backup but then the next incremental will be very much larger as it then will contain all changed data since the time the Full was created, which may defeat the object here!

When deleting any Acronis backup files then you need to be using the Clean up versions tool provided and not doing this manually via Explorer.

See KB 61844: Acronis True Image 2019, 2020 and 2021: How to delete old backups

The alternative is to set and use automatic cleanup to manage your backup files for you.

Automatic cleanup

There can be lots of confusion around the topic of automatic cleanup which can be better understood if some basic concepts are known!

First:  automatic cleanup only works on complete(d) versions / version chains.  Do not expect individual elements of version chains to be cleaned up, such as incremental or differential files!

Second: automatic cleanup only runs after a new Full backup for the next version / version chain has been created successfully.  This means that there must be sufficient free space available on the storage drive / location to hold a new Full backup image file!

Third: counting of days does not start until after a new Full backup file has been created when using the option to ‘Delete versions / version chains older than X days.’  It does not start for the active backup version / version chain before that point!

Fourth: the simplest & easiest automatic cleanup option to use & understand is to ‘Store no more than X recent versions / version chains.’  The criteria here means that if you set X = 2, then when the X+1 (3rd) version / version chain is created successfully with a new Full backup file, then the oldest version / version chain will be deleted by automatic cleanup.

Example:

Incremental backup task, using Full plus 5 Incremental backups before next new Full backup.

Task scheduled to run daily with automatic cleanup set to ‘Store no more than 2 version chains.’

Day 1 – Full backup created.

Days 2 – 6 Incremental backups created.

Day 7 – Next new Full backup created. 

Days 8 – 12 Incremental backups created.

Day 13 – Next new Full backup created.  Automatic cleanup deletes files created on days 1 – 6.

If the same task used ‘Delete version chains older than 7 days’, then those 7 days wouldn’t start counting until day 7 for the first set of files (version chain 1) and not until day 13 for the second set etc.  So automatic cleanup wouldn’t delete the oldest chain until day 14 in the above example.