From owner-freebsd-questions Fri Sep 18 19:15:02 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id TAA29148 for freebsd-questions-outgoing; Fri, 18 Sep 1998 19:15:02 -0700 (PDT) (envelope-from owner-freebsd-questions@FreeBSD.ORG) Received: from mail.HiWAAY.net (fly.HiWAAY.net [208.147.154.56]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id TAA29139; Fri, 18 Sep 1998 19:15:00 -0700 (PDT) (envelope-from dkelly@n4hhe.ampr.org) Received: from nospam.hiwaay.net (tnt2-64.HiWAAY.net [208.147.148.64]) by mail.HiWAAY.net (8.9.0/8.9.0) with ESMTP id VAA22627; Fri, 18 Sep 1998 21:14:34 -0500 (CDT) Received: from n4hhe.ampr.org (localhost.ampr.org [127.0.0.1]) by nospam.hiwaay.net (8.8.8/8.8.8) with ESMTP id UAA04692; Fri, 18 Sep 1998 20:40:52 -0500 (CDT) (envelope-from dkelly@n4hhe.ampr.org) Message-Id: <199809190140.UAA04692@nospam.hiwaay.net> X-Mailer: exmh version 2.0.2 2/24/98 To: Chris Shenton cc: questions@FreeBSD.ORG, scsi@FreeBSD.ORG From: David Kelly Subject: Re: st0: 262144-byte record too big (reading SGI tar tape) In-reply-to: Message from Chris Shenton of "18 Sep 1998 13:58:49 EDT." <87k931fgkm.fsf@absinthe.shenton.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Fri, 18 Sep 1998 20:40:51 -0500 Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Chris Shenton writes: > J Wunsch writes: > > > You cannot read SGI tapes (with their default blocksize) on FreeBSD, > > due to limitations in physio(9) (which have been constrained by older > > SCSI controllers that cannot handle more than 16 scatter/gather > > segments). > > Any suggestions for blocksize? The "st" man page suggests a maximum of > 64KB so I was thinking 32K. Should that be OK? If your write the tape on the SGI with a 64k or smaller blocksize then you'll be OK. (tar -cvb 128 file(s)...) You can also modify /var/sysgen/*/scsi, then build a new kernel (autoconfig), and change your SGI's default tape blocksize. (sorry, I forgot what directory the scsi file is in, you can't miss it. I'd love to see FreeBSD break the 64k barrier, at least for controllers that can handle it. Would hope Adaptec 2940's can as SGI uses AIC7880's in the O2 on my desk at work. This topic has come up a time or two in discussion of CAM. In the rewrite for CAM I get the impression the authors decided it was more important to get CAM working than to add features such as large tape blocks. I can't blame them. -- 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