Date: Wed, 28 Apr 1999 12:54:08 -0400 (EDT) From: "Christopher T. Johnson" <cjohnson@neunacht.netgsi.com> To: shocking@prth.pgs.com (Stephen Hocking-Senior Programmer PGS Tensor Perth) Cc: current@freebsd.org Subject: Re: Further on tape & CAM problems Message-ID: <199904281654.MAA37459@neunacht.netgsi.com> In-Reply-To: <199904130114.JAA21725@ariadne.tensor.pgs.com> from Stephen Hocking-Senior Programmer PGS Tensor Perth at "Apr 13, 99 09:14:18 am"
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Some extra information on tape problems: FreeBSD neunacht.netgsi.com 4.0-CURRENT FreeBSD 4.0-CURRENT #0: Thu Apr 22 16:50:33 EDT 1999 root@:/m/src/sys/compile/NEUNACHT i386 This is SMP machine with scsi only. The tape drive is an EXABYTE-8200. When doing tape IO that lasts for an extend period of time the tape drive will show an amber light. This normally means SCSI activity. At that point any reads or writes to the device happen at 1.4Mbytes/second when the max I know that this drive will do is 0.24 Mbytes/second. We've replaced the tape drive. We've tested with different tapes. It LOOKS like the drive is detecting some sort of error and then going into "toss data mode". This has cost me lots and lots of backups and is very distressing. One interesting data point. When I issue an mt erase command it runs for a fairly long time. It should runn for just over 2 hours. It gets about 3/4s of the way and stops. Again with the orange light. The interesting data point is that four tapes have all stopped at almost the same point. (Visual inspection of amount of media left on the reels.) Any help would be very nice. Thank you, Chris > When the tape hangs with an unkillable process, its relevant PS flags are > "physstrat" and "DL+". It doesn't hang forever, just a very long time, like > someone's confused milliseconds with microseconds, or some such. > > > Also, when writing to the 2nd tape in a CPIO archive, it doesn't actually > write to the tape. systat -vmstat records lots of stuff going to the tape > device (a SCSI QIC-525 in this case) very quickly - way beyond the speed it > can actually do but there's no actual activity. Dump on the otherhand seems > fine. > > > Stephen > -- > The views expressed above are not those of PGS Tensor. > > "We've heard that a million monkeys at a million keyboards could produce > the Complete Works of Shakespeare; now, thanks to the Internet, we know > this is not true." Robert Wilensky, University of California > > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-current" in the body of the message > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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