Deleting old backups

GH, welcome to these public User Forums.

The option to delete a backup in the GUI is found via the drop-down menu associated with each backup task you have configured as shown in the image below:

The important factor to understand is that this Delete option will delete both the task and its settings as well as all the files created by the task.

If you want to just delete unwanted old backup files, then the best & recommended way of doing so is to use the Automatic Cleanup rules provided for each backup task, on the Backup Scheme settings page.

See the ATI 2017 User Guide information below on Automatic Cleanup

Automatic cleanup rules

To delete obsolete backup versions automatically, you can set one of the following cleanup rules:

• Delete versions older than [defined period] (available for full method only) - Select this option to limit the age of backup versions. All versions that are older than the specified period will be automatically deleted.
• Delete version chains older than [defined period] (available for incremental and differential methods only) - Select this option to limit the age of backup version chains. The oldest version chain will be deleted only when the most recent backup version of this chain is older than the specified period.
• Store no more than [n] recent versions (available for full method only) - Select this option to limit the maximum number of backup versions. When the number of versions exceeds the specified value, the oldest backup version will be automatically deleted.
• Store no more than [n] recent version chains (available for incremental and differential methods only) - Select this option to limit the maximum number of backup version chains. When the number of version chains exceeds the specified value, the oldest backup version chain will be automatically deleted.
• Keep size of the backup no more than [defined size] - Select this option to limit maximum size of the backup. After creating a new backup version, the program checks whether the total backup size exceeds the specified value. If it's true, the oldest backup version will be deleted.

Note that a backup version chain = 1 x Full backup plus all associated Incremental or Differential files for that version i.e. that share the same _b?_ number in the file names.

Dear Mr Smith,

Thank you for your detailed and prompt response.

Your response confirms that one indeed cannot delete old backups by following the Manual instructions, as quoted in my question, because no list of backups is displayed.

I assume that by “a backup task” you referred to what the Acronis User Manual calls “a backup scheme” (Section 4.4.2 in the Manual).

I tried to delete old backups in the GUI because the manual stated in Section 4.5.6,

“When you want to delete backups and backup versions you no longer need, please do it by using the tools provided by Acronis True Image 2017”.

Is there any problem with deleting an old backup by simply deleting the related files (the original full backup and subsequent incremental/differential backups) in the Windows Explorer?

Is there any problem with deleting an old backup by simply deleting the related files (the original full backup and subsequent incremental/differential backups) in the Windows Explorer?

If there is a backup task / scheme in the console that relies on them, then yes.  Acronis has an internal database that writes information about created backup .tib files locations and names.  When manually deleted in Explorer, there is no update to the database so it expects that they still exist in those locations.  The way to "fix" this is to run a validation of the backup in Acronis and when it says that files are missing and wants you to locate them or ignore them, click on IGNORE and they will be purged from the database.  The downside is you have to do this for each .tib file that was manually removed so you may have to "ignore" quite a few.  Once it's done, then it will be in sync again.

And/or if the backup job/task is no longer in the Acronis console, then you're fine to just delete .tib files from explorer.  Just make sure that you don't delete critical versions if you plan on keeping some of them.  For instance if you have the original full and 20 incrementals, if you delete incremental 1, then 2-19 are useless now too.

The backup job/task is the name of the backup job that shows up in the left panel of the Acronis GUI.  The "scheme" is the type of backup you chose (full, incremental, differential, etc and includes the # of backups in the chain and automated cleanup rules).

I assume that by “a backup task” you referred to what the Acronis User Manual calls “a backup scheme” (Section 4.4.2 in the Manual).

No, the backup scheme describes how your backup task will perform the backup action.

A backup task is created using the 'Add backup' option where you give this a name, i.e. My Disks, then configure what Source data will be included, where the backup will be stored, what type of backup scheme will be used, what schedule used etc.

Is there any problem with deleting an old backup by simply deleting the related files (the original full backup and subsequent incremental/differential backups) in the Windows Explorer?

Yes, if you delete backup files using Windows Explorer, you leave behind information which Acronis has stored in an internal database about those files and the task that created them.  When you next run that backup task, you will be shown popup error messages for each deleted file.

You can choose to delete files in this way, but you should then use the task option to Validate the backup afterwards, then when the error messages are shown, take the Ignore option if shown, or else the Cancel option and repeat this for each message until the validation is complete.

Acronis have introduced a better way of managing these backups in ATI 2019 by providing a 'Cleanup versions' tool in the drop-down menu for each task.

Dear Mr Smith,

Thank you very much for your detailed and very useful responses.