From mboxrd@z Thu Jan  1 00:00:00 1970
From: Chris Samuel <chris@csamuel.org>
Subject: Re: announcement of deduplication in Sun ZFS
Date: Tue, 3 Nov 2009 10:04:37 +1100
Message-ID: <200911031004.57592.chris@csamuel.org>
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On Tue, 3 Nov 2009 07:51:52 am Alex Dedul wrote:

> In any way thats a nice and interesting feature, thanks! :)

My concern would be that it increases the impact of a corruption of the blo=
ck=20
that has been de-dup'd - in other words if the block that now represents th=
e=20
same data in lots of files gets trashed then all those files have corrupt=20
data. This implies that you would want to keep around at least one other co=
py=20
of that data to be resilient in the face of corruption (checksums will let =
you=20
detect it, but not necessarily recover from it without duplicate copies).

Given that ZFS prides itself on detecting errors it would be strange if the=
y=20
hadn't considered this in the implementation but I couldn't see any mention=
 of=20
it. =20

cheers,
Chris
=2D-=20
 Chris Samuel  :  http://www.csamuel.org/  :  Melbourne, VIC

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