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Date: Sat, 22 Dec 2012 03:25:41 -0600
From: Mark Felder <feld@feld.me>
To: Alex Povolotsky <tarkhil@webmail.sub.ru>
Subject: Re: Strange problem with... ZFS? Disk? Controller?
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Try running diskinfo -t /dev/...

If it says your device is really slow it's probably dying. I'd suspect =
it's having trouble seeking.