LAAKSONE@FINFUN.BITNET (03/23/89)
Please tell me what I'm doing wrong. I'm doing a backup with tar of my files on a 4D/70GTB. I don't want to waste good tape so I try to write the new files after the last one on the tape. Iris man pages do not mention anything about the "-r" key which should add the new files after the last file and tar is complaining with the message "tar:blocked tapes cannot be updated" if I try to use "-r". Ok, next try: I used "tar tf /dev/nrtape" to get to the last file on tape and then I tried with "tar cv files" to add the new files. The man pages are saying for "c": Create a new tape; writing starts at the beginning of the tape instead of after the last file. This option assumes that you are at the beginning of the tape. What happens if I'm not at the beginning? No success the tape is first rewinded and the files are written at the begining of the tanpe. To use just "tar v files" does not work either. What should I do to add new files after the last file on a cartridge tape? Leif Laaksonen Centre for Scientific Computing ESPOO FINLAND
blbates@AERO4.LARC.NASA.GOV (Bates TAD/HRNAB ms294 x2601) (03/23/89)
If the 4D/70GTB is like the 3000's, you can't do what you're trying to do. Our documentation says that you can ONLY create an entire tape at one time, you CAN'T append to a tape that already has information on it. This is very annoying. Another annoyance is that archives can't be spread over multiple tapes. -- Brent L. Bates NASA-Langley Research Center M.S. 294 Hampton, Virginia 23665-5225 (804) 864-2854 E-mail: blbates@aero4.larc.nasa.gov or blbates@aero2.larc.nasa.gov
kvancamp@PICA.ARMY.MIL (Ken Van Camp) (03/24/89)
> If the 4D/70GTB is like the 3000's, you can't do what you're trying >to do. Our documentation says that you can ONLY create an entire tape >at one time, you CAN'T append to a tape that already has information on >it. This is very annoying. Yes, it is true of the 4D's as well. >Another annoyance is that archives can't >be spread over multiple tapes. That's what SGI told me when we bought our original 3020's, but we tried it and it worked fine. I have restored several volumes of tapes this way with no ill effects. I have also tried this out on the 4D's with no problem. --Ken Van Camp ARPANET: kvancamp@PICA.ARMY.MIL -or- kvancamp@ARDEC.ARPA BITNET: (use above through normal gateways, like UBVM.CC.BUFFALO.EDU) USENET: pica.army.mil!kvancamp@UUNET.UU.NET
dat@ORVILLE.NAS.NASA.GOV ("David A. Tristram") (03/24/89)
Leif, After you read to the end of the tape, either with tar tf /dev/nrtape or with "mt fsf <n>", you might try 'writing' to the the no rewind tape device with "tar cvf /dev/nrtape files" or even "tar cvf - files | dd bs=250k of=/dev/nrtape" What we do for multi volume backups is make lists of the files we want to back up using find, and then use a utility we wrote called tarsz that estimates the size of the resulting tar archive. Then we split the list into separate lists, each with only enough files to fit on one tape. Dave
jeremy@denali.SGI.COM (Jeremy Higdon) (03/24/89)
You should be able to append to a 1/4 inch cartridge tape by doing: mt feom tar cf /dev/nrtape <filenames> mt feom positions you at end of data. tar to /dev/nrtape causes tar not to rewind the tape at the beginning. One little speed hint for 4D's is that if you are backing up large files, you may actually get better speed if you use a buffer of about 8k. This is because the 60MB cartridge tape has an internal 16k buffer, so you get double buffering. The standard tar buffer size is 200k, which is good for typical files. Be sure you read a tape back with the same blocksize it was written with. Jeremy Higdon
jeremy@perf2.SGI.COM (my non-net account) (03/24/89)
'mt feom' is a new command in release 3.1D. Sorry if anyone tried it only to be given a list of choices which didn't include feom.
eap@bu-cs.BU.EDU (Eric Pearce) (03/24/89)
In article <8903231551.AA02202@aero4.larc.nasa.gov> blbates@AERO4.LARC.NASA.GOV (Bates TAD/HRNAB ms294 x2601) says: > > If the 4D/70GTB is like the 3000's, you can't do what you're trying >to do. Our documentation says that you can ONLY create an entire tape >at one time, you CAN'T append to a tape that already has information on >it. This is very annoying. Another annoyance is that archives can't >be spread over multiple tapes. Has anybody tried GNU tar on the SGI? (I can't try it myself at the moment) It does multi-volume archives and incremental backups and restores. I don't know if it would solve the tape positioning problems you are having with the 1/4" drive. It's worth a try. (you can get it from prep.ai.mit.edu) -- ------------------------------------------------------------------------------- Eric Pearce ARPANET eap@bu-it.bu.edu Boston University Information Technology CSNET eap%bu-it@bu-cs 111 Cummington Street JNET jnet%"ep@buenga" Boston MA 02215 UUCP !harvard!bu-cs!bu-it!eap 617-353-2780 voice 617-353-6260 fax BITNET ep@buenga
msc@ramoth.SGI.COM (Mark Callow) (03/25/89)
In article <28925@bu-cs.BU.EDU>, eap@bu-cs.BU.EDU (Eric Pearce) writes: > > Has anybody tried GNU tar on the SGI? (I can't try it myself at the > moment) It does multi-volume archives and incremental backups and > restores. I don't know if it would solve the tape positioning > problems you are having with the 1/4" drive. It's worth a try. > > (you can get it from prep.ai.mit.edu) > It won't help. The problem is the 1/4" controller and drive. I believe it's common to all 1/4 inch archive tapes. The man page for tar on SunOs release 4.0 says r ... Note: this option does not work with quarter-inch archive tapes. SGI's tar handles multi-volume tar files. Beer/Bru is good for backup. -- -Mark