From owner-cvs-all Mon Dec 21 12:17:49 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id MAA17485 for cvs-all-outgoing; Mon, 21 Dec 1998 12:17:49 -0800 (PST) (envelope-from owner-cvs-all@FreeBSD.ORG) Received: from apollo.backplane.com (apollo.backplane.com [209.157.86.2]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id MAA17472; Mon, 21 Dec 1998 12:17:33 -0800 (PST) (envelope-from dillon@apollo.backplane.com) Received: (from dillon@localhost) by apollo.backplane.com (8.9.1/8.9.1) id MAA47294; Mon, 21 Dec 1998 12:17:22 -0800 (PST) (envelope-from dillon) Date: Mon, 21 Dec 1998 12:17:22 -0800 (PST) From: Matthew Dillon Message-Id: <199812212017.MAA47294@apollo.backplane.com> To: Dag-Erling Smorgrav Cc: Tim Jones , "Jordan K. Hubbard" , Matt Jacob , cvs-committers@FreeBSD.ORG, cvs-all@FreeBSD.ORG Subject: Re: cvs commit: src/sys/sys mtio.h References: <82280.913951353@zippy.cdrom.com> <367A7E50.B0F5AA3B@estinc.com> Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk :> offer Quick File Access. This means that the user can say "Restore :> mydatafile.dbf" and BRU will fast forward the tape to the appropriate :> logical block address and restore the file. This means a file 2GB deep :> on a DAT tape will restore in 30 seconds, instead of 45 minutes. : :Will this also speed up 'mt [fb]s[fr]'? : :DES :-- :Dag-Erling Smorgrav - des@flood.ping.uio.no No. fsf, fsr, bsf, bsr are implemented with SCSI commands which we already support. Logical block seeking is requires the use of SCSI commands that we do not (did not) support. Logical block seeking would be a good thing, but not all tape drives can actually do it. DAT drives usually can. I don't know about exabytes. Logical block seeking is faster then reading because the tape drives are generally able to fast forward and fast rewind to 'around' the right position, then figure it out from there. If you have several incrementals on the same tape restoring one file will still take a little while - probably at least 5 to 10 minutes, but you still win big time with a logical block seek capability. -Matt Matthew Dillon Engineering, HiWay Technologies, Inc. & BEST Internet Communications & God knows what else. (Please include original email in any response) To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message