[Duplicity-talk] Full backups

[lists]

Hi,

I use duply to back up a number of things to the local HDD, which are then 
rsynced to two external HDDs when I bring either of them home.

I was doing a Full backup every time that I brought the drives home, as I 
was leaving them overnight doing a verify in any event. Of course, I now have 
500GB of backups and need to thin them down again. Before I do that, I wanted 
to post and make sure that I was clear on what that would mean. As I 
understand it, the backups are stored as incremental from a full, so if I 
delete all but the most recent two backups (which are both quite recent), I 
will lose all of the versioning that I had prior to the earliest full.

There is therefore a bit of a tension between Full backups (which are more 
likely restorable) and incremental backups (which provide all intermediate 
versions). There are options so that it deletes the ones that are older than 
x months etc., but it seems to me that the "max full" option cuts across that 
and is going to mean that my backups are shorter than that setting. Is that 
correct?

How do others strike this balance? At the moment for important things I'm 
thinking of having it do a Full backup every two months (with the Full Max 
Age parameter) and keep two of them (so that I have four months of versions), 
but to do a "Verify" every time that I am backing up to my external HDDs to 
confirm that it can restore. I have different things (photos, home videos 
etc) separated into different duply profiles, so I have the luxury of, for 
example, keeping two sets of the important Photos profile, but only one set 
of the very large Home Videos.

Thanks,

Aaron