FreBSD 9.1 and ZFS v28 performances

[Davide D'Amico]

Il 20.03.2013 02:34 Bob Friesenhahn ha scritto:
> On Mon, 18 Mar 2013, Davide D'Amico wrote:
>>> While running the tests what sort of thing are you
>>> seeing from gstat, any disks maxing? If so primarily
>>> read or write?
>> Here the r/w pattern using zpool iostat 2:
> 
> Using 'zpool iostat 2' is not likely to be very useful since zfs
> writes all of is data in bursts and may wait up to 5 seconds to do so.
> 
> If your benchmark uses synchronous writes and does continous updates,
> then you should see zfs writing continiously to your zil device (or
> the pool).

And so, considering I'm using an SSD as ZIL device, I don't understand 
why ZFS performances are so slow (0.5x UFS performances).

My benchmark is a set of 50k queries (select, insert, updates) that 
'stress' the FS more than the 'simple' oltp tests.

Thank,
d.