I've got some data that is being backed up to tape via bacula, and at some point soon I am going to need to migrate to non-tape storage.
Bacula supports to-disk archiving, but it occurred to me that if only there was some virtual tape library interface to S3 or openstack Swift, or some other object store service, I could just swap out the configurations and maintain the pre-existing archiving, ageing and scheduling configurations seamlessly.
I had a google, and I can see that Amanda (using a Device API) and a bunch of backup products have S3 object store back-ends, but I don't see any projects that would drop-in replace using *nix /dev/st0 device interface semantics.
This may well be because I have no idea, and that the idea is preposterous and impossible, etc, however I'd be interested to know if I have missed any obvious things before I delve into some hacked up replacement.
So clarify the the platform options – its not hosted on AWS and there is at present no EBS available and the target is an in-house S3 compatible openStack Swift object store, so bandwidth and storage costs are internal.
Best Answer
This is more than a questionable approach for anything anyone could consider a backup but you should be able to give it a try. The first thing you need would be anything that presents a block interface on top of S3. Something like a NBD server with a S3 backend - have a look at this.
After you got that working you need something that presents a file on top of a block device and offers a SCSI target/virtual HBA to your system with a changer and a tape drive. Have a look at this project here.
See the S3NBD project (first link) for additional rationale why running your backup and recovery with S3 might be a bad idea (with the current S3 pricing scheme).