incremental backups using cpio...HOW???

[Steve Paddock]

In article <155 at csd_v.UUCP| bak at csd_v.UUCP (Bruce) writes:
|
|I have a problem with backups that I've never seen mentioned anywhere
|on the net and I'm wondering if I'm missing some very obvious solution.
|
|I wnat to do multi-volume incremental backups.  My version of tar
|( microport 2.3 sys V ) doesn't support multi-volume archives.  So that
|leaves me with cpio.
|
|My problem is that once an archive has been created say via
|
|$ /bin/ls /usr/bak/src | cpio -oBvc |/dev/dsk/0s25
|
|any subsequent invocation of the same command recreates the archive
|instead of adding to it.  So that if I've deleted files form /usr/bak/src
|since the previous backup, I lose them forever.  Is there some way that
|I can add files to a cpio created archive that I don't know about?
|
|Thanks in advance for all help in this matter.
|-- 
What I do is create a file /etc/lastbak, and touch it after each
successful backup.  I then use find / -newer /etc/lastbak -print|cpio -o[etc.]

Since I'm using a 6300 Plus, not uPort, I use cpiopc to get the actual
multivolume cpio archive.  

Problem with this approach is that you may well have a fit problem
if you do a full restore.