From owner-freebsd-questions Tue Mar 16 4: 1: 0 1999 Delivered-To: freebsd-questions@freebsd.org Received: from alpha.comkey.com.au (alpha.comkey.com.au [203.9.152.215]) by hub.freebsd.org (Postfix) with SMTP id 52D9215043 for ; Tue, 16 Mar 1999 03:57:16 -0800 (PST) (envelope-from gjb@comkey.com.au) Received: (qmail 27452 invoked by uid 1001); 16 Mar 1999 11:55:07 -0000 Message-ID: <19990316115507.27451.qmail@alpha.comkey.com.au> X-Posted-By: GBA-Post 1.04 06-Feb-1999 X-PGP-Fingerprint: 5A91 6942 8CEA 9DAB B95B C249 1CE1 493B 2B5A CE30 Date: Tue, 16 Mar 1999 21:55:07 +1000 From: Greg Black To: robert Cc: freebsd list Subject: Re: dump problem References: <36ED5B73.8E5101CD@mhi-tx.com> In-reply-to: <36ED5B73.8E5101CD@mhi-tx.com> of Mon, 15 Mar 1999 13:11:48 CST Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > I am having a problem with dump or my tape drive. > I have a partition 2gig /usr that I am trying to backup onto an hp dat > drive with a 2gb tape (4gb) compressed. however near the end of the > backup about 77% I get a tape write error. and I am asked if I want to > restart. if I say yes this continues over and over at 77% otherwise it > aborts and I dont get all of my backup. > I have a feeling that it is at the end of the tape and instead of the > drive giving a end of medium it just spits out an error, therefore not > giving me the chance to put in another tape. I tried using -s feet but > my tapes say 90meter wich is about 968 feet but that says I will need > like 156 tapes to do this backup which can't be right. You probably want to first find out a bit more about what you can do with that drive and the tapes you're using. Compression is often not featured on drives that handle 90 metre tapes, so you could first test for that with something like this: dd if=/dev/zero of=/dev/rst0 bs=64k Obviously, replace the /dev/rst0 with whatever is appropriate for your drive. If the drive doesn't do compression, it'll probably accept around 1.8 GB of data (about average for "2 GB" tapes); if it does compression, it'll take heaps since /dev/zero compresses rather well :-) The capacity indicated by this method is not any indicator of the real compressed capacity of the tape, since real data doesn't often consist of billions of zero bits. Once we know how this goes, the next questions will become more evident. -- Greg Black To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message