sow@luthcad.UUCP (04/15/87)
I have some questions about rmt. In bsd4.2 the maximum blocksize is defined as 10240 bytes, by historical reasons (PDP). Can I increase the maximum blocksize? What is the maximum blocksize for rmt on a Sun? I don't want to find it out the hard way. Rmt uses the vax bsd4.2 "tape operations codes" from "sys/mtio.h", as the communication protocol. Is it common that all systems has the same operations codes in mtio.h? The communication protocol should be separated from the system dependent mt operation codes. Sven-Ove Westberg, CAD, University of Lulea, S-951 87 Lulea Tel: +46-920-91677 (work) +46-920-48390 (home) UUCP: sow@luthcad.UUCP or seismo!mcvax!enea!luthcad!sow ARPA: enea!luthcad!sow@seismo.css.gov
roy@phri.UUCP (Roy Smith) (04/24/87)
In article <664@luthcad.UUCP> sow@luthcad.UUCP (Sven-Ove Westberg) writes: > I have some questions about rmt. Since he brought it up, can somebody tell me if rtar has ever been implemented? Rdump and rrestore are the only programs I know that use remote tape drives, but many is the time I wished for rtar. -- Roy Smith, {allegra,cmcl2,philabs}!phri!roy System Administrator, Public Health Research Institute 455 First Avenue, New York, NY 10016 "you can't spell deoxyribonucleic without unixrno
mkhaw@teknowledge-vaxc.ARPA (Michael Khaw) (04/24/87)
In article <2644@phri.UUCP> roy@phri.UUCP (Roy Smith) writes: > Since he brought it up, can somebody tell me if rtar has ever been >implemented? Rdump and rrestore are the only programs I know that use >remote tape drives, but many is the time I wished for rtar. There is a workaround: tar cfB - file | rsh remotehost 'dd of=remote_tape bs=20b' # write rsh remotehost 'dd if=remote_tape bs=20b' | tar xf - # read Note: Although man files for tar may claim/imply that 20 blocks is the maximum block size for tar, vendors of Sun software routinely use 126 blocks for 1/4-inch tar cartridges, and I've seen 126 blocks used successfully with 9-track mag tapes. Mike Khaw -- internet: mkhaw@teknowledge-vaxc.arpa usenet: {hplabs|sun|ucbvax|decwrl|sri-unix}!mkhaw%teknowledge-vaxc.arpa USnail: Teknowledge Inc, 1850 Embarcadero Rd, POB 10119, Palo Alto, CA 94303
hope@gatech.edu (Theodore Hope @ LEGOLAND) (04/24/87)
In article <2644@phri.UUCP> roy@phri.UUCP (Roy Smith) writes: >Rdump and rrestore are the only programs I know that use >remote tape drives, but many is the time I wished for rtar. I don't know if you'd consider the following a kludge, but I use the following to read a tar tape on a remote machine: % rsh remote dd of=/dev/rmt8 ibs=10240 | tar xvf - (tar bs of 20) An analogous command can be used to write tar on a remote tape. -- Theodore Hope School of Information & Computer Science, Georgia Tech, Atlanta GA 30332 CSNet: Hope@gatech ARPA: Hope@Gatech.EDU uucp: ...!{akgua,decvax,hplabs,ihnp4,linus,seismo,ulysses}!gatech!hope
dik@mcvax.cwi.nl (Dik T. Winter) (04/25/87)
In article <15097@gatech.gatech.edu> hope@gatech.UUCP (Theodore Hope @ LEGOLAND) writes: > I don't know if you'd consider the following a kludge, but I > use the following to read a tar tape on a remote machine: > > % rsh remote dd of=/dev/rmt8 ibs=10240 | tar xvf - (tar bs of 20) > > An analogous command can be used to write tar on a remote tape. A problem with this is that you need an account on the machine with the tape drive. At our site we have a number of vaxen with different user groups, but only a few of these vaxen have tapedrives. This has been solved, and we now have rtar. I do not know the status of it. -- dik t. winter, cwi, amsterdam, nederland INTERNET : dik@cwi.nl BITNET/EARN: dik@mcvax
baccala@USNA.MIL (Brent W Baccala) (04/25/87)
> Since he brought it up, can somebody tell me if rtar has ever been > implemented? Rdump and rrestore are the only programs I know that use > remote tape drives, but many is the time I wished for rtar. Volume 2 of the mod.sources archives contains "rtar", which is described as "diffs to tar to sue a remote system's tape drives". I can't remember what system(s) it's for, since its been a long time since I looked at it... - BRENT W. BACCALA - Computer Aided Design/Interactive Graphics U.S. Naval Academy Annapolis, MD <decvax!brl-smoke!usna!baccala> <seismo!usna!baccala> <baccala@usna.arpa>
kurt@hi.uucp (Kurt Zeilenga) (04/26/87)
Hope@gatech.UUCP (Theodore Hope @ LEGOLAND) writes: >In article <2644@phri.UUCP> roy@phri.UUCP (Roy Smith) writes: >>Rdump and rrestore are the only programs I know that use >>remote tape drives, but many is the time I wished for rtar. > >I don't know if you'd consider the following a kludge, but I Not a kludge, this is even documented (in my SUN 3.3 manual). >use the following to read a tar tape on a remote machine: > > % rsh remote dd of=/dev/rmt8 ibs=10240 | tar xvf - (tar bs of 20) When running tar with input being a pipe, it is usually a good idea to add a "B" flag, read the manual for more info... I use: % rsh remote -n dd of=/dev/rmt0 bs=20b | tar xvBfb - 20 <files> -- Kurt Zeilenga (zeilenga@hc.dspo.gov)
lamy@utegc.UUCP (04/26/87)
In article <15097@gatech.gatech.edu> hope@gatech.UUCP (Theodore Hope @ LEGOLAND) writes: >I don't know if you'd consider the following a kludge, but I >use the following to read a tar tape on a remote machine: > > % rsh remote dd of=/dev/rmt8 ibs=10240 | tar xvf - (tar bs of 20) It's not a kludge, it's documented in the Sun man page :-). Writing is a bit harder, though, if you want to be able to do a 'tar r', since (quite logically) tar r does not make sense on standard output. 4.3 tar handles remote drives, so I fished it out and compiled it and friends on a Sun, but alas, no luck. 'tar r' works fine locally on the 4.3 BSD Vax, but not from the Sun, where the subsequent archives don't show up in a tar t. Looked in the source, and the rmt stuff looks perfectly orthodox. We only have one machine running 4.3, so I could not try from a remote one... Also, I often find myself doing a big find -prune ... followed by a session of purification with a text editor, in order to get a reasonable list of files to put on tape. In the absence of 'tar r', using xargs to handle a huge list of arguments is out of the question, and the only tar I know that can read standard input for its list of files is John Gilmore's etar, but that one does not support on the fly change of directories, and does not follow symbolic links. Am I missing something? Ah well. I cross-posted to comp.unix.questions and redirected follow-ups there. Jean-Francois Lamy lamy@ai.toronto.edu (CSNet, UUCP) AI Group, Dept of Computer Science, lamy@ai.toronto.cdn (EAN) University of Toronto, Ont, Canada M5S 1A4 lamy@ai.utoronto (Bitnet)
rbj@icst-cmr.arpa (Root Boy Jim) (04/27/87)
It's not a kludge, it's documented in the Sun man page :-). Writing is a bit harder, though, if you want to be able to do a 'tar r', since (quite logically) tar r does not make sense on standard output. Possibly, but `tar c' does. See the example (option f) in the man page. AI Group, Dept of Computer Science, lamy@ai.toronto.cdn (EAN) University of Toronto, Ont, Canada M5S 1A4 lamy@ai.utoronto (Bitnet) (Root Boy) Jim "Just Say Yes" Cottrell <rbj@icst-cmr.arpa> Life is a POPULARITY CONTEST! I'm REFRESHINGLY CANDID!!