Hello,
I took two USB sticks, I put them on different USB controllers (the iMac has 3 of them), then I copied the same file (movie) from internal to each USB flash drive. Speed measured: 10-12 MB/s each. That's good, it means that even on the same USB2 controller, they would not saturate it.
I generated a mirror as written in the ZEVO PDF and I tried to copy the same movie: less than 1 MB/s. Is it normal?
I aborted the process (and it took a very long time to abort) and I copied an application (77 MB).
I ejected the zfs volume, tried to mount it again with Disk Utility, experienced the kernel panic mentioned in another thread, rebooted, the copied the application to the desktop. I measured about 7 MB/s, still less than 20 MB/s I expected from a mirror pool.
Could someone else check the performances? Unfortunately I cannot test with real HD and they would be USB anyway, since I use an iMac.
I will try striping now.