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Date: Sun, 20 Sep 2015 17:11:49 -0400
From: Quartz <quartz@sneakertech.com>
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Subject: Re: ZFS cpu requirements, with/out compression and/or dedup
References: <CAEW+ogbPswfOWQzbwNZR5qyMrCEfrcSP4Q7+y4zuKVVD=KNuUA@mail.gmail.com>
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> Any algorithm for TB's of storage and cpu/ram is usually wrong.

dedup is kind of a special case though, because it has to keep the 
entire DDT in non-paged ram (assuming you want the machine to be usable).

Of course, the rule of thumb is for USED space. 40TB of blank space 
won't need any ram obviously.