From owner-freebsd-questions Wed Sep 15 7:46:57 1999 Delivered-To: freebsd-questions@freebsd.org Received: from netmint.com (netmint.com [207.106.21.130]) by hub.freebsd.org (Postfix) with ESMTP id DF2D21529F for ; Wed, 15 Sep 1999 07:46:17 -0700 (PDT) (envelope-from andriss@andriss.com) Received: from localhost (andriss@localhost) by netmint.com (8.9.3/8.9.3) with ESMTP id KAA86102; Wed, 15 Sep 1999 10:45:26 -0400 (EDT) Date: Wed, 15 Sep 1999 10:45:20 -0400 (EDT) From: Andriss X-Sender: andriss@netmint.com To: Greg Lehey Cc: Graeme Tait , Woody Carey , questions@FreeBSD.ORG, info@boatbooks.com Subject: Re: SCSI drive mirroring question In-Reply-To: <19990915200957.I30655@freebie.lemis.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG -----BEGIN PGP SIGNED MESSAGE----- >> I've used dd successfully to replicate a drive to an identical drive, and >> it may well be much faster than file-by-file methods, depending on what >> is on the drive to be copied (in particular, how full the drive is). BTW, >> I believe this also copies any boot record, etc. >> >> But this was with the source drive mounted read-only. What would happen >> if dd was used to copy a live filesystem, and when the system >> wrote a given file, data was written both before and after the current >> read point for dd? > >The data would be inconsistent. That's why we have things like Vinum. Since copying a live filesystem with dd seems dangerous, I may have to unmount the source drive. How long do you think it will take dd to duplicate a 9.1 Gb UltraStar 18es u2w SCSI drive, chained on a 2940u2w controller onto another identical UltraStar? Andriss - -- ______________________________________________________________ Andrey Kholodenko http://www.andriss.com Download My Public PGP Key From http://www.andriss.com/pgp.txt ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -----BEGIN PGP SIGNATURE----- Version: 2.6.3a Charset: noconv iQCVAwUBN9+xBiQe9jf/ODl9AQEgHAP/c4pfykmj+y3OVBWbQlO7lGjeckvS3NgM mEB9aQnwZCg3LuwFUSNAta9FHmu95OPhVcjPeGMkJTWeUR7YIMPnt96iX5OcPjV4 9fJt+Phjp0XNOEx2yIPK1G2yXbMYwtC92jCSDEgMxVX96jsjj7vP2ca23TgFZVsw 1+iLkFzWaGg= =60Kb -----END PGP SIGNATURE----- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message