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Date: Sat, 17 Sep 2016 13:04:56 +0000 (UTC)
From: matthew patton <pattonme@yahoo.com>
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Subject: Re: [linux-lvm] creating DD copies of disks
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	LVM general discussion and development <linux-lvm@redhat.com>
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> What is the proper procedure when duplicating a disk with DD?

If you're literally duplicating the entire disk, what on earth are you doing keeping it in the same system? OF COURSE you remove it from the origin box if you expect to do anything with it. And I presume there are no active filesystems or frankly writable LVM components on the source disk while the DD is running? 

Most times it's only the filesystems that contain interesting data an so a DD of the filesystem is understandable even though there are other tools like RSYNC which are more logical.

If you're trying to make a forensic copy, please delegate the task to professionals, who know what they are doing.