MPIO

I'm considering native Multi Path I/O (MPIO) as an alternative to EMC PowerPath 5 for stability reasons. MPIO has been native since the 2.6.13 kernel. Back ports have been in RHEL since version 4U2. Dell has an overview and the multipath-tools project page's ReferenceBook has more details. The 2005 Linux Symposium (pages 155-175) also covers it and calivia.com has test results.