Date: Fri, 31 Oct 2008 11:37:09 -0400 From: Jerry McAllister <jerrymc@msu.edu> To: Christoph Kukulies <kuku@kukulies.org> Cc: freebsd-questions@freebsd.org Subject: Re: fastest raw device copy? Message-ID: <20081031153709.GC17878@gizmo.acns.msu.edu> In-Reply-To: <490AC650.3000904@kukulies.org> References: <490AC650.3000904@kukulies.org>
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On Fri, Oct 31, 2008 at 09:48:16AM +0100, Christoph Kukulies wrote: > Hi list, > > I'm considering using a bootable USB stick with FreeBSD to perform a > backup of my notebooks' > 500 GB hard disk to a physically identical (same make, same type, same > size) hard disk attached to USB. > > What would be the fastest way to do that sector by sector copy? I'm > using dd right now, > > dd if=/dev/ad0 of=/dev/da0 bs=10000000 > > but maybe there is a utility which does this faster or a larger buffer > size? Probably the limit will be > the USB 2.0 bus speed anyway? Are you sure you want to do a sector-by-sector copy? That won't get you much that is useful in terms of a backup. Can't you use dump/restore instead? Dump each file system on /dev/ad0 to a file on /dev/da0. Create a file system on /dev/da0 using newfs first. You may or may not want to create a FreeBSD slice and partition there before doing the newfs. Make a mount point and mount it. mkdir /bkmnt mount /dev/da0 /bkmnt Or if you created slice and partition in /dev/da0 mount /dev/da0s1a /bkmnt Then do the dumps dump 0af /bkmnt/rootbackup / dump 0af /bkmnt/usrbackup /usr dump 0af /bkmnt/homehackup /home etc for whatever file systems you want to back up. You will be much better off than with a sector by sector copy. ////jerry > > -- > Christoph > > _______________________________________________ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.org"
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