unattended cpio backup script

[Leslie Mikesell]

In article <2630 at sixhub.UUCP> davidsen at sixhub.UUCP (bill davidsen) writes:

>  Almost. You very much want the 'a' option on cpio whenever you do a
>backup, so you don't reset the access time. The true (user) access time
>is useful when you want to find files which haven't been accessed for N
>months and use them as candidates for the bit bucket or archiving.

Unfortunately however, in the process of resetting the atime to pretend
that you didn't read the file you set the ctime thus indicating an
inode modification that you can't tell from some significant change
like renaming or changing the owner or modes.  Thus, you can't mix
using the 'a' option with doing incremental backups based on ctime.
The only way to get both things right is to mount the fs read-only
while doing the backup or do it across a read-only network mount.

Les Mikesell
  les at chinet.chi.il.us