immense delayed write to file system (ZFS and UFS2), performance issues

[Tommi Lätti]

Seems that the performance is indeed atrocious. I recently (like 2
days ago) had to rescue my zfs pool under opensolaris to spare disks.
The performance under OpenSol was what I was expecting, 70MB/s reading
and writing at the same time.

Now that I'm restoring the stuff back under FreeBSD 8.0-p2 it seems
that first the array reads from the source disk and then stops reading
and decides to empty the buffer to the destination. There's usually a
2 second pause and after that it goes back to reading. There seems to
be something really wrong with this, fbsd zfs implementation seems to
be unable to move data between 2 zfs pools writing and reading
simultaneously...

I think I'll just boot back to opensol and do the transfers there.

-- 
br,
Tommi