Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!att!pacbell.com!mips!zaphod.mps.ohio-state.edu!wuarchive!uunet!garfield!odie.cs.mun.ca!harold From: harold@odie.cs.mun.ca (Harold Wareham(Todd)) Newsgroups: comp.sys.sgi Subject: HELP: SGI 4D/360 EXABYTE problem: Command DD Message-ID: <1991May27.192352.24630@garfield.cs.mun.ca> Date: 27 May 91 19:23:52 GMT Sender: usenet@garfield.cs.mun.ca (NNTP server account) Distribution: na Organization: CS Dept, Memorial University of Newfoundland Lines: 243 Originator: harold@odie.cs.mun.ca We are having problems with an EXABYTE-8200 hooked up to an SGI-4D/360 running SGI UNIX version 3.3.1. Specifically, we cannot read or write an EXABYTE tape using the command DD; however, we can create and read tapes using the command TAR. The drive was cleaned prior to the problems described in this message (the same day as the tests run below, in fact). To add strangeness to it all, one can use DD with a QIC drive, but it refuses to read back the last (partial) block from tape. Odd, yes? Details follow. If you have any ideas about what's going on, drop me a line. - Todd Todd Wareham harold@odie.cs.mun.ca |"Success in science depends not Department of Physics | only on rational argument but Memorial University of Newfoundland | on a mixture of subterfuge, St. John, NF, Canada | rhetoric, and propaganda" | - Feyerabed **************************** DETAILS ********************************* Scripts of the various errors encountered are given below. The following is the script of trying to read from our EXABYTE drive (/dev/mt/tps0d6) a tape containing a single large file (20484 6000-byte records); just to be sure switching from byte-swapping to no byte-swapping reads was causing no problems, I popped the tape out between the read attempts. This tape was created at another EXABYTE drive on campus attached to a MIPS-120 running UNIX 4.3 BSD. This tape reads and writes fine (using DD) on that other system on that other drive. Script started on Mon May 27 15:08:34 1991 % ls -l /dev/mt/tps0d6* crw-rw-rw- 3 root sys 23,192 May 27 14:15 /dev/mt/tps0d6 crw-rw-rw- 3 root sys 23,193 May 27 13:57 /dev/mt/tps0d6nr crw-rw-rw- 3 root sys 23,195 Nov 7 1990 /dev/mt/tps0d6nrns crw-rw-rw- 3 root sys 23,194 May 27 14:15 /dev/mt/tps0d6ns % mt -t /dev/mt/tps0d6 status Controller: SCSI Device: EXABYTE: EXB-8200 252T Status: 0x246 Media : READY, write protected, at BOT % mt -t /dev/mt/tps0d6 rewind % mt -t /dev/mt/tps0d6 status Controller: SCSI Device: EXABYTE: EXB-8200 252T Status: 0x246 Media : READY, write protected, at BOT % dd if=/dev/mt/tps0d6 bs=6000 of=/dev/null dd: read error: Invalid argument 0+0 records in 0+0 records out % mt -t /dev/mt/tps0d6 status Controller: SCSI Device: EXABYTE: EXB-8200 252T Status: 0x266 Media : READY, write protected, at BOT ... tape popped ... % mt -t /dev/mt/tps0d6 status Controller: SCSI Device: EXABYTE: EXB-8200 252T Status: 0x244 Media : READY, write protected, not at BOT % mt -t /dev/mt/tps0d6ns status Controller: SCSI Device: EXABYTE: EXB-8200 252T Status: 0x246 Media : READY, write protected, at BOT % mt -t /dev/mt/tps0d6ns rewind % mt -t /dev/mt/tps0d6ns status Controller: SCSI Device: EXABYTE: EXB-8200 252T Status: 0x246 Media : READY, write protected, at BOT % dd if=/dev/mt/tps0d6ns bs=6000 of=/dev/null dd: read error: Invalid argument 0+0 records in 0+0 records out % mt -t /dev/mt/tps0d6ns status Controller: SCSI Device: EXABYTE: EXB-8200 252T Status: 0x266 Media : READY, write protected, at BOT % exit % script done on Mon May 27 15:14:14 1991 Thinking it might be a MIPS idiosyncrasy, I then tried reading the first file (1 8000-byte block) of a tape created on a system not on campus (details unknown). For the record, this tape reads fine on the MIPS system described above. Script started on Mon May 27 15:17:42 1991 % mt -t /dev/mt/tps0d6 status Controller: SCSI Device: EXABYTE: EXB-8200 252T Status: 0x244 Media : READY, write protected, not at BOT % mt -t /dev/mt/tps0d6 rewind % mt -t /dev/mt/tps0d6 status Controller: SCSI Device: EXABYTE: EXB-8200 252T Status: 0x246 Media : READY, write protected, at BOT % dd if=/dev/mt/tps0d6 bs=8000 of=/dev/null dd: read error: Invalid argument 0+0 records in 0+0 records out % mt -t /dev/mt/tps0d6 status Controller: SCSI Device: EXABYTE: EXB-8200 252T Status: 0x266 Media : READY, write protected, at BOT ... tape popped ... % mt -t /dev/mt/tps0d6ns status Controller: SCSI Device: EXABYTE: EXB-8200 252T Status: 0x244 Media : READY, write protected, not at BOT % mt -t /dev/mt/tps0d6ns rewind % mt -t /dev/mt/tps0d6ns status Controller: SCSI Device: EXABYTE: EXB-8200 252T Status: 0x246 Media : READY, write protected, at BOT % dd if=/dev/mt/tps0d6ns bs=8000 of=/dev/null dd: read error: Invalid argument 0+0 records in 0+0 records out % mt -t /dev/mt/tps0d6ns status Controller: SCSI Device: EXABYTE: EXB-8200 252T Status: 0x266 Media : READY, write protected, at BOT % exit % script done on Mon May 27 15:21:40 1991 Failing that, I tried writing and reading a tape on our own drive. Script started on Mon May 27 15:36:42 1991 % mt -t /dev/mt/tps0d6 status Controller: SCSI Device: EXABYTE: EXB-8200 252T Status: 0x240 Media : READY, writable, not at BOT % mt -t /dev/mt/tps0d6 rewind % mt -t /dev/mt/tps0d6 status Controller: SCSI Device: EXABYTE: EXB-8200 252T Status: 0x242 Media : READY, writable, at BOT % dd if=grib.f of=/dev/mt/tps0d6 dd: write error: Invalid argument 1+0 records in 1+0 records out % mt -t /dev/mt/tps0d6 status Controller: SCSI Device: EXABYTE: EXB-8200 252T Status: 0x262 Media : READY, writable, at BOT % mt -t /dev/mt/tps0d6 rewind % mt -t /dev/mt/tps0d6 status Controller: SCSI Device: EXABYTE: EXB-8200 252T Status: 0x262 Media : READY, writable, at BOT % dd if=/dev/mt/tps0d6 of=grib.f.ret.2 dd: read error: Invalid argument 0+0 records in 0+0 records out % mt -t /dev/mt/tps0d6 status Controller: SCSI Device: EXABYTE: EXB-8200 252T Status: 0x262 Media : READY, writable, at BOT % exit % script done on Mon May 27 15:38:58 1991 Finally, I decided to try our local QIC (/dev/mt/tps0d7) to see if there were problems with DD on other devices. Script started on Mon May 27 15:23:20 1991 % ls -l /dev/mt/tps0d7* crw-rw-rw- 3 root sys 23,224 Apr 11 11:50 /dev/mt/tps0d7 crw-rw-rw- 3 root sys 23,225 May 3 15:15 /dev/mt/tps0d7nr crw-rw-rw- 3 root sys 23,227 Dec 3 16:01 /dev/mt/tps0d7nrns crw-rw-rw- 3 root sys 23,226 May 27 14:34 /dev/mt/tps0d7ns % mt -t /dev/mt/tps0d7 status Controller: SCSI Device: ARCHIVE: VIPER 150 21247-005 VP1 Status: 0x240 Media : READY, writable, not at BOT m% t -t /dev/mt/tps0d7 rewind % mt -t /dev/mt/tps0d7 status Controller: SCSI Device: ARCHIVE: VIPER 150 21247-005 VP1 Status: 0x242 Media : READY, writable, at BOT % ls -l grib.f -rw-r--r-- 1 harold physics 34757 May 21 11:50 grib.f % dd if=grib.f of=/dev/mt/tps0d7 dd: write error: Invalid argument 67+1 records in 67+1 records out % mt -t /dev/mt/tps0d7 status Controller: SCSI Device: ARCHIVE: VIPER 150 21247-005 VP1 Status: 0x262 Media : READY, writable, at BOT % mt -t /dev/mt/tps0d7 rewind % mt -t /dev/mt/tps0d7 status Controller: SCSI Device: ARCHIVE: VIPER 150 21247-005 VP1 Status: 0x262 Media : READY, writable, at BOT % dd if=/dev/mt/tps0d7 of=grib.f.ret 67+0 records in 67+0 records out % ls -l grib.f grib.f.ret -rw-r--r-- 1 harold physics 34757 May 21 11:50 grib.f -rw-r--r-- 1 harold physics 34304 May 27 15:26 grib.f.ret % exit % script done on Mon May 27 15:27:47 1991 And that's all she (didn't) wrote.