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Date: Thu, 21 Jul 2005 19:57:15 -0500
From: Craig Boston <craig@feniz.gank.org>
To: "Eli K. Breen" <bsd@unixforge.net>
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Cc: freebsd-stable@freebsd.org
Subject: Re: Machine Replication
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On Thu, Jul 21, 2005 at 12:20:34PM -0700, Eli K. Breen wrote:
> dd		(Slow, not usefull if the hardware isn't identical?)

I use dd a lot for this type of thing and don't see how it could
possibly be slower than any other method that duplicates the entire raw
drive.  Make sure to give it a "bs=1m" option as reading/writing the
disk in 512 byte chunks is a lot slower than larger blocks.

If your disks have a lot of free space, copying the filesystem using
dump/restore can be faster, but it's not an *exact* bit-for-bit copy.
The resulting filesystem is functionally equivalent though, so it's
probably the best way for duplicating UFS(2) filesystems.  You do have
to partition manually, but you would probably want to do that if the new
drive was a different size anyway.

Craig