[Hcoop-discuss] On-disk backup policy

[Adam Chlipala]

Months ago, I set up rsnapshot on fyodor to create on-disk backups of 
/home and /etc.  It uses hard links to save a remarkable amount of 
space, such that we currently have 12 additional copies of old versions 
of /home and /etc stored on /home!

However, all these copies still use up space, especially for files that 
change often.  I left the default settings for number of different 
backup images to store at once:
    interval        daily   7
    interval        weekly  4
    interval        monthly 6

With these settings, it looks like we have ratios as bad as 3/4 of space 
used by a user being associated with backups.  Does anyone have any 
suggestions on what more appropriate counts would be?  I'm thinking 
something like daily 2, weekly 1, and monthly 1.

Also, I'm still hoping someone will take on finding the right ferm rules 
to enable us to mount a local NFS share, which presents backups to users 
to restore themselves when needed.  It's not possible to just grant 
users access to the backup directories, because then they'd be able to 
modify them, since the backups also preserve file permissions.