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Date: Thu, 23 May 2013 08:09:27 -0700
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Subject: Re: file corruption solution (soft-update or ZFS)
From: Michael Sierchio <kudzu@tenebras.com>
To: Warren Block <wblock@wonkity.com>
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Cc: saeedeh motlagh <saeedeh.motlagh@gmail.com>,
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On Thu, May 23, 2013 at 5:33 AM, Warren Block <wblock@wonkity.com> wrote:

> ..

>  One thing mentioned earlier is that ZFS wants lots of memory.  4G-8G
> minimum, some might say as much as the server will hold.
>
>
Not necessarily so - deduplication places great demands on memory, but that
can be satisfied with dedicated cache devices (on SSD for performance and
safety reasons).  Without dedup, the requirements are more modest.

Softupdates guarantee metadata consistency, but do nothing to address data
integrity. ZFS has copy-on-write semantics (which solve a problem that even
hardware RAID can't), and end-to-end checksums to detect/prevent data
corruption (large drives will have uncorrectable bit errors over their
lifetime).

- M