Date: Fri, 10 Feb 2006 10:27:07 -0500 From: Ken Stevenson <ken@allenmyland.com> To: freebsd-questions@FreeBSD.org Subject: Re: Using dd to Make a Clone of a Drive Message-ID: <43ECB0CB.1040005@allenmyland.com> In-Reply-To: <20060209220123.GA4751@flame.pc> References: <200602092036.k19KaIhn086956@dc.cis.okstate.edu> <20060209220123.GA4751@flame.pc>
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Giorgos Keramidas wrote: > On 2006-02-09 14:36, Martin McCormick <martin@dc.cis.okstate.edu> wrote: >> After installing FreeBSD5.4, the ISC dhcp server and ISC bind >> on a hard drive, I wanted to clone that drive to a second drive so as >> to generate a second server, using what I had already installed as a >> template. I used the following command: >> >> dd if=/dev/da0 of=/dev/da1 bs=512 >> >> It turns out that dd defaults to 512-byte blocks so I didn't >> really need the bs=512, but I am not sure I haven't made some other >> type of mistake. The dd command has been running for about 4 hours on >> a very fast system, with a 1-gig processor, 1 gig of RAM and two 31-GB >> drives. One would think it should have finished by now, but it is >> still running. Is this a valid method of copying the entire contents >> of one drive to another? Thank you. > > Bah! That's too slow for my taste. I would usually go for a newfs, > dump, and restore option. For instance, to create a copy of /usr on a > second disk: > > newfs -U /dev/ad1s1a > mount /dev/ad1s1a /mnt > dump -0 -a -L /usr | ( cd /mnt ; restore ruvf - ) > > Copying with dd(1) is not as fast :) > I had to clone a couple systems a while back, and I also did it with dump/restore. The best part was this was the first time I actually restored my backups to a bare hard drive. It gave me a lot of confidence that my backups actually work. I think a lot of people find out too late that whatever backup solution they're using is flawed and they can't rebuild their system from it. -- Ken Stevenson Allen-Myland Inc.
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