Backup to tape directly off Ceph?

[proxwolfe]

Hi,

I am planning a new Ceph cluster with three nodes (and three OSDs in total). For my purpose, I consider this sufficient.

Of course, I want to perform backups on that. But I do not want to first backup to a local disk (and create yet another copy of my data) and from there on-backup to tape. Rather, I am hoping for a way to backup to tape directly from one of the OSDs. Is that feasible?

Thanks!

 

[tom]

This is not possible, you always need to store backups on file based datastore first.

 

[proxwolfe]

you always need to store backups on file based datastore first

And do the backups need to stay on the file based datastore as well (because this may be needed to make incremental backups possible) or can they be deleted once copied to tape?

Thanks!

 

[tom]

I do not recommend this but yes, the tape contains all data.

If you want to do further incremental backups, you cannot delete the datastore.

 

[proxwolfe]

If you want to do further incremental backups, you cannot delete the datastore.

Does this also mean that, if I want to be able to make incremental backups, my (disk based) datastore needs to be at least as big as my tape (library)?

 

[tom]

Your datastore needs to be big enough to hold your backup data. Dedup helps to keep the amount of data as low as possible.

 

[proxwolfe]

Your datastore needs to be big enough to hold your backup data.

Right. My question was phrased incorrectly. What I meant was: If I want to make incremental backups utilising the entire capacity of my tape (library), do I need to have a datastore just as big? And I take it, the answer is yes.

Or in other words: Tape does not increase my storage capacity (if I want to be able to make incremental backups), right?

Thanks!

 

[tom]

Or in other words: Tape does not increase my storage capacity (if I want to be able to make incremental backups), right?

yes, Tape backups are just an offline archive/copy and do not affect the file-based datastore.