Date: Fri, 03 Aug 2001 08:42:51 -0700 From: "Kevin Oberman" <oberman@es.net> To: Christopher Farley <chris@northernbrewer.com> Cc: freebsd-questions@FreeBSD.ORG Subject: Re: Cloning a hard drive - performance issues Message-ID: <200108031542.f73Fgpm19225@ptavv.es.net> In-Reply-To: Your message of "Thu, 02 Aug 2001 19:50:19 CDT." <20010802195017.A503@northernbrewer.com>
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> Date: Thu, 2 Aug 2001 19:50:19 -0500 > From: Christopher Farley <chris@northernbrewer.com> > Sender: owner-freebsd-questions@FreeBSD.ORG > > I've got a drive that started throwing hard read errors. I'm going to > copy it onto a fresh drive. (Details below, if it's relevant.) > > Using 2 ATA/66 drives, this has proven to be very, very SLOW. So I'm left > with a hardware question: > > Which is faster: > > a) Leave both drives on the same cable, set one as master and the other > as slave > b) Put each drive on its own cable, set them both as master > c) No difference > d) Depends on your mainboard b) should always be faster (assuming there is no activity to any slave device on either controller). > Here is my 'cloning' process - perhaps this is just a slow operation: > > I've prepared my new drive with fdisk, disklabel and newfs. To perform > the 'clone' I'm mounting the new filesystem on /mnt, and piping dump into > restore like this: > > cd /mnt > dump -0uaf - /dev/ad0s1a | restore -rf - You call this 'cloning'. If the new and slices have the same geometry, dd is MUCH faster. I clone my laptop HD weekly with: dd bs=32k if=/dev/ad0s1 of=/dev/ad2s1 # Windows slice dd bs=32k if=/dev/ad0s1 of=/dev/ad2s2 # FreeBSD slice Note that the slices are identical, but the disks are not. (I am cloning 2 of 4 slices on a 12 GB disk onto a 6 GB disk.) You can further speed this up using team from ports. You can also use dd to clone identical partitions. I clone the 6 GB in about 13 minutes. Also, make sure write caching is enabled. It was off in 4.3-Release and will kill you on this type of operation. (It was on in 4.2 and is back on in -stable.) > -- > Christopher Farley > www.northernbrewer.com > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-questions" in the body of the message > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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