From owner-freebsd-fs@FreeBSD.ORG  Fri Apr 12 09:44:52 2013
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Date: Fri, 12 Apr 2013 13:44:47 +0400 (MSK)
From: Dmitry Morozovsky <marck@rinet.ru>
To: Charles Sprickman <spork@bway.net>
Subject: Re: ZFS-inly server and dedicated ZIL
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On Thu, 11 Apr 2013, Charles Sprickman wrote:

> On Apr 10, 2013, at 9:23 AM, Dmitry Morozovsky wrote:
> 
> > Dear colleagues,
> > 
> > I'm planning to make new PostgreSQL server using zaid10-like ZFS with two SSDs 
> > splitted into mirrored ZIL and striped arc2.
> 
> This might seem like an odd suggestion, but if you're putting the pool on 
> SSDs (is that correct?), I'd totally skip the separate ZIL device and ARC.  
> I think you'll find the SSDs will need zero help from another log device and 
> L2ARC is probably just not that helpful for DB loads.

No, this will be 8*SAS in 4 mirrored pairs + 2*SSD for mirrored ZIL and striped 
l2arc. Like the following (this is from other machine, but similar in setup):


        NAME        STATE     READ WRITE CKSUM
        pn          ONLINE       0     0     0
          mirror-0  ONLINE       0     0     0
            da0     ONLINE       0     0     0
            da6     ONLINE       0     0     0
          mirror-2  ONLINE       0     0     0
            da1     ONLINE       0     0     0
            da7     ONLINE       0     0     0
        logs
          mirror-1  ONLINE       0     0     0
            da2d    ONLINE       0     0     0
            da3d    ONLINE       0     0     0
        cache
          da2e      ONLINE       0     0     0
          da3e      ONLINE       0     0     0


-- 
Sincerely,
D.Marck                                     [DM5020, MCK-RIPE, DM3-RIPN]
[ FreeBSD committer:                                 marck@FreeBSD.org ]
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*** Dmitry Morozovsky --- D.Marck --- Wild Woozle --- marck@rinet.ru ***
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