Thanks to all for the helpful comments and questions.
[EMAIL PROTECTED] said: > Isn't MPXIO support by HBA and hard drive identification (not by the > enclosure)? At least I don't see how the enclosure should matter, as long as > it has 2 active paths. So if you add the drive vendor info into /kernel/drv/ > scsi_vhci.conf it should work. If the enclosure is JBOD, then yes, the drives would be the targets of MPXIO. But for a RAID enclosure, it's the RAID controller which speaks SCSI, adds and removes LUN's, etc. The three different arrays I've used have all had settings where you specify what kind of alternate-path "protocol" to speak to the various hosts involved. [EMAIL PROTECTED] said: > In a so called symmetric mode it should work as you described. But many entry > level and midsize arrays aren't actually symmetric and they have to be > treated specifically. This matches my limited experience. What Sun calls "asymmetric" seems to match what some array vendors call "active/active with LUN affinity" (or "LUN ownership"). MPXIO "knows" about such asymmetric arrays, but some arrays don't speak the right protocol (T10 ALUA), and there's so far no way to manually tell MPXIO to do the asymmetric thing with them. For example, our low-end HDS array looks to MPXIO as if it's symmetric, since both controllers show their configured LUN's all the time. But only one controller can do I/O to a given LUN at one time, and the array takes a long while to swap ownership between controllers, so MPXIO's default round-robin load balancing yields terrible performance. The workaround is to manually set load-balancing to "none" and hope MPXIO uses the controller that you were wanting to be primary. And some people wonder why I prefer NAS over SAN...(:-). Regards, Marion _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
