How many ram...

[Linda Kateley]

Jas,

Most of those rules of thumbs are not valid. ZFS doesn't really need to 
keep data about metadata in ram. It keeps recently used and frequently 
used items in cache. There are some per disk caches but by default those 
are pretty small.

I have a blog on a group that has a 350TB archive/backup system with 
32GB ram. http://kateleyco.com/?p=815

Everything is dependent on use case. If you have many users all using 
the same file, frequently.. that will be cached. Sizing workload helps.

linda

On 1/13/15 4:52 AM, Albert Shih wrote:
> Hi all,
>
> Basic question : How many amount of ram I need for running ZFS with a pool
> of ~500-600To.
>
> For example If I've a server with 2 disk array of 60 disk of 6To.
>
> Is the rule I find somewhere on Internet saying for ZFS 1To --> 1Go is
> still true ?
>
> What's happen If I use less ram ? Like 1To --> 0.5Go ? Less performance ? crash ?
>
> Regards.
>
> JAS
>
> --
> Albert SHIH
> DIO bâtiment 15
> Observatoire de Paris
> 5 Place Jules Janssen
> 92195 Meudon Cedex
> France
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> xmpp: jas at obspm.fr
> Heure local/Local time:
> mar 13 jan 2015 11:49:16 CET
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-- 
Linda Kateley
Kateley Company
Skype ID-kateleyco
http://kateleyco.com