From: utzoo!decvax!cca!lazear@MITRE@sri-unix Newsgroups: net.unix-wizards Title: Re: dump Article-I.D.: sri-unix.1633 Posted: Sat Jun 5 22:49:21 1982 Received: Sun Jun 6 05:24:31 1982 Date: Fri, 21 May 1982 0830-EDT The Air Force Data Services Center has done extensive work in improving dump's capabilities: - it will dump at either 800 or 1600 bpi - it can block up to 8 Unix blocks per tape block - it can create identical backup tapes - the code is documented at least to the subroutine level Similar work has been done with restor: - it will restore at 800/1600, with various blocking factors - it has commented code - it can recover from tape errors in several ways: - by requesting a backup tape and seeking to the same place on that tape and continuing (this can go on forever, switching tapes (much like avoiding potholes on a two-lane road)) - by 'checkpointing' at each inode and losing only one inode in the case of no backup tape and a tape error (we recovered a 56000 blk filsys with 10 tape errors (no backup) and lost only 4 files!) The source is available by sending a tape to: Charles Muir, AFDSC/CMT, Room 1D988, Pentagon, Wash, DC 20330 Walt Lazear (formerly AFDSC, now Mitre)