tar -C / --exclude='./proc/*' -cf /dev/nst0 . does not exclude /proc. tar -1.13.?? (as shipped on RedHat 6.1) does exclude. The exclude pattern in version 1.12 is not being compared against a pathname with a leading "./". The leading "./" is missing. Or that's what it _seems_ like is happening. I haven't looked at the source code. Tapes are filling up and the system is not getting full backups. Installing tar 1.13 fixes this.
Version 1.12 of tar also was not able to read a tar file created on a hp-ux 9 system.
Tar-1.13.n is available in Raw Hide. Can you supply a small hppux 9 tar ball for analysis and testing? Thanks.