[Dirvish] Archival storage of dirvish backup sets

[Dave Howorth]

Joe Aquilina wrote:
> How do I work out which backups I can safely write to dvd/blu-ray and 
> then delete from the backup server?

That's entirely a matter for your own discretion, based on your own
business needs.

> I have found a few places while 
> googling that mention that this can be done but without really giving 
> any detail as to exactly how this can be achieved safely.
> 
> And once a backup set/snapshot has been written to dvd/blu-ray, what 
> is the best (i.e. safest) way of deleting it from the collection of 
> snapshots on the hard disc?

You can just copy a particular snapshot to a disk in the same way you
would copy any other files. Similarly you can just delete any particular
snapshot using rm -r <snapshot-directory>

If you configure dirvish properly, dirvish-expire will delete unwanted
backups automatically.

Don't forget that DVDs and Blu-rays don't last forever. You will need
more than one copy and you'll need to rewrite them regularly onto new
disks. I don't use them for backup myself, so I can't tell you how often.