Date: Sat, 20 Mar 1999 00:28:19 +1000 From: Stephen McKay <syssgm@detir.qld.gov.au> To: mjacob@feral.com Cc: freebsd-scsi@FreeBSD.ORG, syssgm@detir.qld.gov.au Subject: Re: Strange SCSI QIC tape behaviour Message-ID: <199903191428.AAA12777@nymph.detir.qld.gov.au> In-Reply-To: <Pine.LNX.4.04.9903130853210.4639-100000@feral-gw> from Matthew Jacob at "Sat, 13 Mar 1999 09:17:04 -0800" References: <Pine.LNX.4.04.9903130853210.4639-100000@feral-gw>
next in thread | previous in thread | raw e-mail | index | archive | help
I've discovered a little more about the behaviour of the TDC4200 as it relates to the current driver and fixed vs variable blocking. My earlier message described some of my difficulty reusing variable blocked tapes, even after 'mt erase'. I have just found that 'mt density 0' is required or you get nowhere. Strangely, it seems to have no effect as far as 'mt status' is concerned, though it certainly changed the behaviour of the drive. I think the SCSI tape driver maintains some sort of state that is out of date, and maintains it even over reinsertions of the tape media. So 'mt density 0' just gets it to resync with what the drive thinks is going on. I got as far as sasetparams() in scsi_sa.c, but now I know I need to read a lot more of the SCSI spec, and that could take quite some time. Stephen. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199903191428.AAA12777>