Date: Sun, 9 Feb 1997 10:20:03 -0800 (PST) From: Bill Paul <wpaul@skynet.ctr.columbia.edu> To: freebsd-bugs Subject: Re: kern/2698: scsi tape driver problem Message-ID: <199702091820.KAA27276@freefall.freebsd.org>
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The following reply was made to PR kern/2698; it has been noted by GNATS. From: Bill Paul <wpaul@skynet.ctr.columbia.edu> To: plm@xs4all.nl Cc: FreeBSD-gnats-submit@freebsd.org Subject: Re: kern/2698: scsi tape driver problem Date: Sun, 9 Feb 1997 13:10:30 -0500 (EST) Of all the gin joints in all the towns in all the world, Peter Mutsaers had to walk into mine and say: > $ dump 1af /dev/rst0 /dev/rsd1f > .... > ... > $ restore tf /dev/rst0 > tape read error: Input/output error > console output: st0: block wrong size, 64 blocks residual What about if you force a particular block size with dump/restore: % dump -b 126 1af /dev/nrst0 /dev/rsd1f % restore -b 126 ivf /dev/nrst0 > Also, I can never read a dump with dd (dd if=/dev/rst0 bs=512 fails): > $ dd bs=512 if=/dev/rst0 of=/dev/null > dd: /dev/rst0: Input/output error > 0+0 records in > 0+0 records out > 0 bytes transferred in 12.830684 secs (0 bytes/sec) > > console output: st0: 10240-byte record too big > > Although I did specify bs=512! But it's telling you that the dumps were written with 512*20 byte blocks. Try using dd with bs=10240 (or bs=20b, which is equivalent). In order to get dump(8) to create a dump volume with 512 byte blocks, you'd have to do 'dump -b1' (1*512). I'm pretty sure it doesn't do that by default, so trying to read the dump back with dd using a 512 byte block size can't possibly work. > Note: using tar instead of dump does not cause such problems. So dump > must do something special to the device that triggers the problem. Could be dump and restore disagree on their default buffer sizes. Out of force of habit, I always explicitly specify a block size with dump and restore, except when running them through pipes to stdin/stdout. -Bill -- ============================================================================= -Bill Paul (212) 854-6020 | System Manager, Master of Unix-Fu Work: wpaul@ctr.columbia.edu | Center for Telecommunications Research Home: wpaul@skynet.ctr.columbia.edu | Columbia University, New York City ============================================================================= "It is not I who am crazy; it is I who am mad!" - Ren Hoek, "Space Madness" =============================================================================
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