From owner-freebsd-questions Sat Feb 20 15:15:55 1999 Delivered-To: freebsd-questions@freebsd.org Received: from mail.HiWAAY.net (fly.HiWAAY.net [208.147.154.56]) by hub.freebsd.org (Postfix) with ESMTP id E212111173 for ; Sat, 20 Feb 1999 15:15:51 -0800 (PST) (envelope-from dkelly@nospam.hiwaay.net) Received: from nospam.hiwaay.net (tnt2-208-147-148-220.dialup.HiWAAY.net [208.147.148.220]) by mail.HiWAAY.net (8.9.1a/8.9.0) with ESMTP id RAA00310; Sat, 20 Feb 1999 17:15:48 -0600 (CST) Received: from nospam.hiwaay.net (localhost [127.0.0.1]) by nospam.hiwaay.net (8.9.2/8.9.2) with ESMTP id RAA86591; Sat, 20 Feb 1999 17:15:34 -0600 (CST) (envelope-from dkelly@nospam.hiwaay.net) Message-Id: <199902202315.RAA86591@nospam.hiwaay.net> X-Mailer: exmh version 2.0.2 2/24/98 To: Greg Black Cc: freebsd-questions@FreeBSD.ORG From: David Kelly Subject: Re: tape drive position In-reply-to: Message from Greg Black of "Sat, 20 Feb 1999 12:01:16 +1000." <19990220020117.4326.qmail@alpha.comkey.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Sat, 20 Feb 1999 17:15:34 -0600 Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Greg Black writes: > > The only way I know to ID a compressed tape is to put it > > in a DDS drive which doesn't support compression and see what happens. > > Same for Irix and FreeBSD. > > One problem with the method is that, on several BSD variants and > with at least two brands of DDS-1 (no compression) drives, what > happens is a system lockup. This is the only thing (apart from > my own stupidity) that has ever forced me to reboot a BSD system. Its been a while since I tried it, but believe a 2.2.x system with a 1st generation Archive DDS the message written to the console suggested the block size on tape was 1 byte, and we couldn't handle that. I too have seen situations where something goes haywire with the tape drive. If one were able to issue a selective RESET without resetting everything on the SCSI bus, that would get things going again. Usually I have external tape drives so power cycling the device solves the immediate problem. Really would like to ID compressed tapes. The compression status reported by "mt status" only reports what will be done the next time the tape drive starts writting at the begining of a new tape. Otherwise compression-capabable tape drives transparently adjust to the compression mode of the tape under their heads. Can't flip compression modes in mid-tape. -- David Kelly N4HHE, dkelly@nospam.hiwaay.net ===================================================================== The human mind ordinarily operates at only ten percent of its capacity -- the rest is overhead for the operating system. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message