ZFS SSD Sample performance observation

[Willem Jan Withagen]

Hi,

I running a full ZFS server, aka the boot partition is also zfs.

And I've been playing today with a SSD i just got:
   ad12: 57241MB <Corsair Force GT 1.2> at ata6-master UDMA100 SATA 3Gb/s

Which supposedly can do > 500 Mb on read and write.

So just for sake of it I tested compiling buildworlds (-j 64).
I know it is not the best test, but it is easy to get at.
And I also know that there are a lot of variable to be tweaked, which is 
not the purpose of the message either.

/usr/src is on /zfsboot (mirror)
/usr/obj is on /zfsraid (raidz2)
Which are both seperate sets of disks.

buildtime for buildworld 0:18:25 , no zfs cache, no zfs log.

creating on the SSD:
	10G cache for /zfsboot
	1G  log   for /zfsraid
	40G cache for /zfsraid

and things speed up to 0:16:05.
(both times on a freshly booted box)

So that is almost a 0:02:20 speedup, aka 13% speedup.
At the cost of about 70 euros.

That is enjoyable.
--WjW

PS: for those interested, dmesg at:
	http://www.tegenbosch28.nl/data/FreeBSD/ZFS.dmesg.txt
PS2: I remember that 20min was the buildKERNEL time. :)