VMWare and ZFS not acceptable

While I can get the system to run I find that the I/O rate with ZFS in VMWare is unacceptable, only about 10 MB/s on a four-disk raid 10. Even with direct access to the disk I believe that ZFS's desire to really own the spindles is not very compatible with VMWare's emulation. Xen my be an option, but at this point I'm just going to run with Linux and hardware raid as the system needs to go into production.