Backup/Disaster Recovery Strategy
I am new to Kopano and just trying to work through disaster recovery scenarios.
Having read the docs, there are two different tools, the database dumb (mysql/mariadb) plus attachments and the kopano-backup tool. To me it looks like for a full disaster (machine rebuild) you need to do a database restore plus an restore of attachments stored externally. Then if your kopano-backup is more recent, do a further restore from there. Is my understanding correct? Just doing a restore from kopano-backup won’t work?
Looking at the output from the kopano-backup tool it noes not seem to look too feasible to do incremental backups as, for example, there is only one inbox file per user so any change to the user’s inbox requires a new backup of the whole folder. Have I missed something here or is it possible to do incremental backups?
Just doing a restore from kopano-backup won’t work?
That is not quite right. Generally speaking doing a disaster recovery from a MySQL Dump is recommended, since it will restore your system to the exact state it was at the time of the backup.
Using kopano-backup will serialise out all the data and doing a restore from this will not be a 1:1 copy of its original self. One thing that changes for example is the last modified date, simply because the item in question has been last modified at the time of restore.
So you could also do a disaster recovery with kopano-backup, but the result will be slightly different from the original source.
Looking at the output from the kopano-backup tool it noes not seem to look too feasible to do incremental backups
Kopano-backup itself is incremental, the data written to disk will be extended with changes since the last run of it. But since the files created by the backup will be updated, the backup data itself cannot incrementally be written somewhere else. There is an switch to backup to write changes to a new set of files instead to make this possible.
Thanks for the response.
For incremental backups are you talking about the --differential switch?
Is there a document for managing differential backups? I presume at some point you need to start merging to old ones to keep the number of copies under control. Do you also need to merge them prior to restoring, say, if you wanted to restore an e-mail from a week ago? Or does the restore go back through all the older incremental backups automatically?
@nickh Yes, I was referring to the differential switch.
Yes, you would indeed need to specify the diff on disk from where you want to restore the item (kopano-backup currently does not traverse all diffs). and for a full restore you should merge the files back in one.
Ok, thanks. I guess differentials are more awkward for restores as you then need to know when a last change was done to know which diff to look into. I’ll need to think about that one.