Booting with multiple paths to a disk
 

Hardware:
IBM BladeCenter with HS20 Blades. 2 QLogic dual port cards (4 ports total)
EMC Clariion CX500

OS:
RHEL 3

Other Software:
PowerPath light

Each blade has the ability to see 4 paths to the same disk though any of the four ports on the FC cards. PowerPath (light) was required so that I could see all four paths. Without this, I could only see two paths (through the primary SP).

How would I go about setting the Linux blade up to see and use all four paths (for failover) as well as boot on any of the living paths?

Initial attemtps have had some success, however, when the fiber was pulled, the OS didn't react well (with i/o errors) despite seeing all four paths registered on the SAN.

Another oddity is that when I specify the root to boot off of, I do not see that path in powermt (the other 3 are listed there though).

Is native multipathing stable & mature in Linux?

Perhaps one of these links can start you on an answer. I used google for this. Admittedly, this is beyond me.

http://lists.us.dell.com/pipermail/l...ry/029584.html
http://lists.community.tummy.com/pip...er/000163.html

PowerPath Base does not work with the CX500 (I saw such an announcement previously). Right now, we are using PowerPath Base.

The other resource didn't seem to contain much real info.

Some other resources which I have used/found (but still having some issues):
http://lists.us.dell.com/pipermail/l...ly/014331.html
http://www.linuxsa.org.au/mailing-li...3-07/1270.html