On Wed, May 28, 2008 at 02:18:39PM -0700, Alex Kompel wrote: > I would not use multipath I/O with iSCSI unless you have specific > reasons for doing so. iSCSI is only as highly-available as you network > infrastructure allows it to be. If you have a full failover within the > network then you don't need multipath. That simplifies configuration a > lot. Provided your network core is fully redundant (both link and > routing layers), you can connect 2 NICs on each server to separate > switches and bond them (google for "channel bonding"). Once you have > redundant network connection you can use the setup from the article I > posted earlier. This will give you iSCSI endpoint failover. This depends on a lot of things. In all of the iSCSI storage systems I'm familiar with, the same target is provided redundantly via different portal IPs. This provides failover in the case of an iscsi controller failing on the storage system. The network can be as redundant as you like, but without multipath, you won't survive a portal failure. If you bond between two different switches, you'll only be able to do failover between the NICs. If you use multipath, you can round-robin between them to provide a greater bandwidth overhead. I'd suggest using multipath. Check the open-iscsi documentation and mailing list archives for tips on tuning the timing for those pieces. -- Ross Vandegrift ross@xxxxxxxxxxx "The good Christian should beware of mathematicians, and all those who make empty prophecies. The danger already exists that the mathematicians have made a covenant with the devil to darken the spirit and to confine man in the bonds of Hell." --St. Augustine, De Genesi ad Litteram, Book II, xviii, 37 -- Linux-cluster mailing list Linux-cluster@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cluster
