Deletion of oldest backups not working

[ctdak]

I'm getting error message "BA706 Insufficient space to complete backup". I'm still new to BA and this is a new disk that is just now getting full with archival backups.

In the job setup under Destination - Replication mode options, I have selected the choice "Use all available space - delete old backups as necessary". I assumed this choice meant that BA would automatically detect when there was insufficient space and delete the oldest backups before starting a new backup. In fact, this is what the help info says about this option. So why isn't this working? I'm using an RDX drive.

[Stuart]

Hi there,

It's Stuart here from the BackupAssist team, thanks for posting on our forum.

What is the scheme that you've selected (this can be found under the scheduling tab)?
I ask this as some of the pre-configured schemes actually require a set, non-configurable number of backups to be retained and won't be deleted until this has been done (Grandfather-Father-Son is an example of this as it requires 23 backups to be kept: 5 daily, 5 weekly, 12 monthly, 1 yearly). If you have configured such a scheme to be used, then the space management won't work unless you have enough space to house that number of backups or else the software can't meet the requirement.

What size is the RDX cartridge that you're backing up to? How much free space is currently available? If there are only a few MB free, then this can cause confusion over space management. Along with this; managing all available space is not the most efficient as if the end of the media is reached then the software will stop transferring data and start performing a delete process, then once some space has been cleared change to transfer. This switching (depending on how many switches are required) can add a lot of extra overhead to the backup and cause the time of backup to escalate.

Typically; if you're writing to a fixed size media like an RDX drive; I recommend that you use the option to 'Keep X number of backups' set to a figure that will fit within the physical space your destination allows (I'd also recommend taking into account and future data growth when you set this figure). This is more efficient because once the number configured is reached, the software will delete the backup freeing up that space. The software will then proceed to copy the latest backup on the destination - no switching back and forth as outlined above which will save processing time.

[ctdak]

Stuart,

The scheme is simple: Mon-Fri with 2 Daily disks used twice each Mon/Wed and Tue/Thu and 5 Weekly disks rotated for Friday (which are my offsite disks). My RDX disks are 320GB capacity and my backup is 24GB so I can get 12 backups on each disk before it gets full. This is a new server and I just got to this point this week, with 2GB to 4GB of space left when trying to do the 13th backup and finding it had not deleted the oldest backup.

From what you said I think I understand the backup options better now. You suggested using the "Keep backups from the last" option selecting 10 days for example, but a certain number of days probably doesn't work too well with my scheme. I think the "Use a maximum size of" option selecting 250GB for backups would work better for me. Or the "Keep the last" option selecting 10 backups. Am I right? (I now see in the help info that any of these options is supposed to delete the oldest backups, which will enable me to keep using the same disks.)

I still don't understand why the deletion didn't happen with my current choice of "Use all available space". Maybe 2GB tpo 4GB wasn't enough space for it to do the deletion.

Thanks for your help.

[Stuart]

Hi again,

It does seem there wasn't enough space left on the drive for it to work properly. While it says use all available space; once it gets down around 5% space left then it can have troubles. You're actually down to 1% - 2% free so this is why it's having issues.

You can choose any of the options you've mentioned - whichever you're comfortable with. I just know from personal experience keeping X amount of backups seems to resolve a lot of these types of issues.

Doing so will resolve your space management issues.