From owner-freebsd-stable Wed May 8 22:34:33 2002 Delivered-To: freebsd-stable@freebsd.org Received: from rwcrmhc52.attbi.com (rwcrmhc52.attbi.com [216.148.227.88]) by hub.freebsd.org (Postfix) with ESMTP id 6842737B410 for ; Wed, 8 May 2002 22:34:28 -0700 (PDT) Received: from mac.com ([12.231.115.57]) by rwcrmhc52.attbi.com (InterMail vM.4.01.03.27 201-229-121-127-20010626) with ESMTP id <20020509053424.DSON25294.rwcrmhc52.attbi.com@mac.com> for ; Thu, 9 May 2002 05:34:24 +0000 Message-ID: <3CDA0A5D.6070803@mac.com> Date: Wed, 08 May 2002 22:34:21 -0700 From: paul beard User-Agent: Mozilla/5.0 (X11; U; NetBSD i386; en-US; rv:1.0rc1) Gecko/20020429 X-Accept-Language: en-us, en MIME-Version: 1.0 To: stable@FreeBSD.ORG Subject: Re: question on dump(8) and SCSI tape drive References: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Lawrence S. Lansing wrote: >>I just installed a DDS-2 tape drive (Archive/Seagate Peregrine >>with HW compression) and want to do some backups. From what I can >>tell, a 120m tape should hold 4 Gb of uncompressed data and 8 Gb >>compressed. I'm puzzled why dump(8) wants 2 tapes to backup 77+ Mb >>of data (the / partition below) and 44% of a tape for /var (16 Mb). >> >> DUMP: estimated 77567 tape blocks on 1.99 tape(s). > > > What flags are you giving "dump"? What's the command line you are typing? > I give dump the -a flag: > > -a ``auto-size''. Bypass all tape length considerations, and > enforce writing until an end-of-media indication is returned. > This fits best for most modern tape drives. Use of this option > is particularly recommended when appending to an existing tape, > or using a tape drive with hardware compression (where you can > never be sure about the compression ratio). > > -Larry Lansing That's what I was thinking was the problem (I couldn't make out how dump figured out 44% of what?). Thanks: things seem to be moving more smoothly now. -- Paul Beard 8040 27th Ave NE Seattle WA 98115 206 529 8400 The economy depends about as much on economists as the weather does on weather forecasters. -- Jean-Paul Kauffmann To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message