Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!noao!tody From: tody@noao.edu (Doug Tody X217) Newsgroups: comp.unix.aux Subject: Re: Multiple cpio/tar files on Apple Tape Message-ID: <1990Mar26.062901.8016@noao.edu> Date: 26 Mar 90 06:29:01 GMT References: Organization: National Optical Astronomy Observatories, Tucson, AZ, USA Lines: 29 From article , by MATLEVAN@EKU.BITNET (Jerry LeVan): > Hello, > Has anyone out there used the Apple Tape Cartridge to store > multiple tar/cpio file archives? It is clear that the "norewind" > device must be used, but does the tape driver write and eof mark? Yes. All unix tape drivers automatically write an EOT (double tape mark) when a file opened for writing is subsequently closed. If closed no-rewind, the tape is left positioned between the file marks and the next file will overwrite the second tape mark, giving you an EOF between the files (those are the standard semantics, the details of what actually goes on at the physical level with the Apple tape may differ, but I doubt that it matters). > Should the "mt" command be used to write eof marks after each > archive? No. That would probably give you an EOT, making the tape difficult to read... Just tar to the new-rewind device, and tar again for each successive file. Very easy. > Is there any way to determine how many archives are stored > on the tape... It is not hard to write a program to count files and records on a tape, but I don't know of anything in A/UX or standard unix. -- Doug Tody, National Optical Astronomy Observatories, Tucson AZ, 602-325-9217 UUCP: {arizona,decvax,ncar}!noao!tody or uunet!noao.edu!tody Internet: tody@noao.edu SPAN/HEPNET: NOAO::TODY (NOAO=5355)