Date: Fri, 30 May 1997 18:30:18 +0200 (MET DST) From: robsch@robkaos.ruhr.de (Robert Schien) To: se@freebsd.org (Stefan Esser) Cc: freebsd-scsi@freebsd.org Subject: Re: How to turn off DAT compression Message-ID: <m0wXUZG-00066yC@robkaos.ruhr.de> In-Reply-To: <19970530131444.53612@x14.mi.uni-koeln.de> from Stefan Esser at "May 30, 97 01:14:44 pm"
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> > This winding forward and backward may indicate a drive > problem. Did you remember to clean the R/W head with > a cleaning cartridge, at least every 50 hours of use ? > (That may be 20 to 50 full backups, depending on your > system's specifics ...) Yes, I tried a cleaning cartridge. Unfortunately, the DAT drive ejected it 10 seconds after loading :-( > > > sessions (or partitions or volumes, I don't know what the correct > > term is when you have miltiple parts on a tape) are destroyed. Two DAT tapes I > > > May 29 13:46:21 robkaos /kernel: st1: COMMAND FAILED (9 ff) @f0637800. > > May 29 13:46:27 robkaos /kernel: ncr0: timeout ccb=f0637800 (skip) > > May 29 13:47:24 robkaos /kernel: ncr0: timeout ccb=f0658e00 (skip) > > May 29 13:47:25 robkaos /kernel: st1: 5.0 MB/s (200 ns, offset 8) > > May 29 13:47:25 robkaos /kernel: sd1: 10.0 MB/s (100 ns, offset 8) > > You got an IBM disk drive ? :) No, Conner 2105S. > > > May 29 13:50:29 robkaos /kernel: ncr0: timeout ccb=f0658e00 (skip) > > May 29 13:50:30 robkaos /kernel: st1: MEDIUM ERROR asc:3,2 Excessive write errors > > Well, this is not a driver message, but a message sent > by your drive !!! > > > BTW, the DAT cartrdges ware brand new (Verbatim). > > > > Robert > > > > P.S.: The system is -current (2 weeks old). > > And the DAT drive ? :) Two years! > > Guess you should first try cleaning your drive's heads. > As long as you get the MEDIUM ERROR messages, there is > no way I could do anything for you ... > I don't think that the MEDIUM ERROR message is 'real'. Under normal conditions (i.e. transfering files which are not easily compressible like audio files) there isn't the slightest problem with the drive. ONLY when transfering files which can be shrinked to 1/10th of their original size by gzip the DAT drive gets crazy. My theory is that there is some problem with the data transfer rate: when reading or writing compressible data the transfer rate increases from a few hundred kb/s to MB/s and my slow PPro-200 isn't capable to transfer the data :-) Robert
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