Hi all,
I'm planning on implementing this in my new upcoming dovecot instance, and would like to hear thoughts on how best to accomplish this. We will be paying Timo's support company to do the work, but obviously, the less work in the form of coding he has to do to get this working (I'm hoping it won't be a lot), the more money it will save us... ;)
First - I currently use rsnapshot to backup emails, so that is the use-case I'm most interested in getting working. It is rsync based, and like other rsync based backup programs it uses hardlinks to save storage space - so you can have a *lot* of backups (going back months, or even years), where each snapshot only adds a little more to the total disk space being used.
The snapshots are stored with the following filesystem layout:
/path/to/snapshotsdir/hourly.0 ... /path/to/snapshotsdir/hourly.4 /path/to/snapshotsdir/daily.0 ... /path/to/snapshotsdir/daily.7 /path/to/snapshotsdir/weekly.0 ... /path/to/snapshotsdir/weekly.4 /path/to/snapshotsdir/monthly.0 ... /path/to/snapshotsdir/monthly.12 /path/to/snapshotsdir/yearly.0 ... /path/to/snapshotsdir/yearly.5
The 'names' (hourly, daily, weekly, monthly, yearly) are arbitrary (this is a bit confusing to people new to rsnapshot), and would *not* be used for displaying the mail folders to the users - it is the Date/Time stamps of each of the snapshot dirs above that would be used to display the folder names under the 'Time Machine' namespace. This is, I imagine, the part that will need some actual coding by Timo to get working - maybe just some new config variables added to the namespace code for mapping the date/time stamps of the directories to user friendly folder names in the namespace.
That said, I'd like to design this and have it coded such that it will work with almost any type of backup storage that stores snapshots as date/time stamped directories like this (there must be others, right?).
Also, it goes without saying that this code will be (if Timo is ok with it) part of the core dovecot code going forward, so anyone else will be able to benefit from it.
What I'm envisioning is something like this...
Define a namespace - for this example we'll call it 'Time Machine'
Under this namespace, each user will see their, and *only* their snapshots
So, each user would see something like this:
My Mail Account Inbox Drafts Templates Sent Time Machine (sorted above user created folders if possible) -4/3/12, 8:00am (first subfolder) Inbox Drafts etc... (all other folders and sub-folders shown here) +4/3/12, 12:00pm (first subfolder) etc... Other User Folders ...
Or even better, I'm thinking some magical code that can group them by Date, like:
-4/3/12 (first subfolder)
-8:00am (next sub-folder)
Inbox
Drafts
Etc... (all folders and sub-folders shown here)
+12:00pm
+4:00pm
+8:00pm
+4/4/12
etc...Comments? Suggestions? Flames?
--
Best regards,
Charles