[OpenIndiana-discuss] ZFS with Dedupication for NFS server

[Tomas Bodzar]

On Sat, Apr 23, 2011 at 3:06 PM, Edward Ned Harvey
<openindiana at nedharvey.com> wrote:
>> From: Roy Sigurd Karlsbakk [mailto:roy at karlsbakk.net]
>>
>> That's theory, in practice, even with sufficient RAM/L2ARC and some amount
>> of SLOG, dedup slows down writes to a minimum. My test was done with 8TB
>> net storage, 8GB RAM, and two 80GB x25-M SSDs devided into 2x4GB SLOG
>> (mirrored) and the rest for L2ARC.
>
> In theory, dedup should accelerate performance when data is duplicated.
>
> In the specs you quoted above, you have not nearly enough ram.  I would say you should consider 4G or 8G to be baseline if you have no dedup and no l2arc.  But when you add the dedup and the l2arc, your ram requirements increase.
>
> With the 8T storage...  Add 8-16G ram to your server on top of your baseline.
>
> I'm not sure how to calculate extra ram requirements for l2arc.

Isn't it too much?  I asked elsewhere and looks like they have lower
needs for RAM http://www.shiningsilence.com/dbsdlog/2011/04/22/7647.html

>
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