ZFS performance on 7.2-release/amd64 low compared to UFS2 + SoftUpdates

[Pete French]

> All the ZFS tuning guides for FreeBSD (including one on the FreeBSD
> ZFS wiki) have recommended values between 64M and 128M to improve
> stability, so that what I went with. How much of my max kmem is it
> safe to give to ZFS?

If you are on amd64 then don't tune it, it will tune itself. If you
are on i386 (or an earlier verions of amd64) then 128M on a 2 gig machine
should be OK, assuming you have kmem_size_max set to the full 1500 odd.
Those are numbers which come up time and time again - I ran reliably with
them for ages, until the latest -STABLE.

-pete.