[geeks] One, two, three, panic!

[Mike Meredith]

On Mon, 16 Mar 2009 14:00:49 -0400, Shannon Hendrix wrote:
> I would actually be willing to occasionally have lower performance
> on Solaris in exchange for lower memory usage on my Solaris 10 box,
> so I might see if you can tune it there too.

See the arc tuning bit of the "Evil ZFS Tuning Guide" :-

   http://www.solarisinternals.com/wiki/index.php/ZFS_Evil_Tuning_Guide

I've done it myself on a 6900 running Oracle as the sole application
although on second thoughts it probably isn't needed.

> It's actually puzzling why ZFS needs to much memory, even after  
> reading some explanations.

I think "need" is perhaps too strong a word. On that previously
mentioned 6900, the DBAs were horrified to discover that the ARC cache
was 17Gbytes in size before being limited and after copying in the
region of 750Gbytes of databases into place on ZFS. Limiting teh ARC to
4Gbytes has made no noticeable difference.

-- 
Mike Meredith (http://zonky.org/)
 ... a software firewall is like bringing a knife to a gunfight.