[OpenIndiana-discuss] Hi - can anybody help me get OI installedthe way I'd like?

[Kimmo Jaskari]

On Sun, Aug 28, 2011 at 06:21, Dan Swartzendruber <dswartz at druber.com> wrote:
>
> Can you elaborate?  Is the fragmentation due to ZIL writes to the same pool
> competing with regular writes?  If one disables sync mode entirely, does the
> same apply?

Personally I hadn't actually given the notion of the ZFS fragmentation
issues any thought at all since I've never really done "serious"
databases on ZFS but I did some digging after Kris's excellent remark
there. This blog entry seems to go into some detail:

http://wildness.espix.org/index.php?post/2011/06/09/ZFS-Fragmentation-issue-examining-the-ZIL

"For the issue not to come again, the solution is to add a mirrored
(or not) log device to the pool, this way, the ZIL transactions are
written to this device and don't fragment the data vdevs of the pool."

So I stand corrected, if you do a database on ZFS you apparently
ideally want a ZIL device.

-- 
-{ Kimmo Jaskari }--{ kimmo.jaskari at gmail.com }--

"Reality is that which, when you stop believing in it, doesn't go
away." -- Philip K. Dick