Multipath setup in RedhatAS4 Update3

[Vikki Wikeley_2]

As part of a planned upgrade to our redhat servers, I am currently building two test nodes but I am running into problems with the multipathing.
Both nodes are rx4640 itanium servers fibre-attached to an EVA5000.
At AS2.1 we managed to get the multipathing working without too much hassle using the platform kit and hp_qla drivers but I having no luck at AS4, I can see each presented lun 4 times intead of only once.

Can someone give me any pointers on how to get multipathing working ?

Thanks in advance,

Vikki

[Steven E. Protter]

Shalom Vikki,

1) Wait for HP to fully support the release. That may take months. You are doomed to fail if you don't wait for supported drivers.

SEP

[Matti_Kurkela]

The multipathing function in the hp_qla drivers is certainly the easiest way to handle multipathed disks, but it is by no means the only way.

In the RedHat ES4/AS4, there is actually two "Linux-native" ways to handle multipathed disks. One is the old, klunky /dev/md - not recommended any more.

The other is called device-mapper-multipath: check the list of packages available through up2date for the correct spelling (the dashes might have been underscores). It's quite new, so it could be a bit "rough around the edges" yet. However, it seems to work for me.

Install the package, then go to /usr/share/doc/ and find the documentation associated with the package. Read it very carefully: there is a "blacklist" line in /etc/multipath.conf that disables all multipath functionality until you explicitly remove it. You must also start up the multipathd daemon and initialize the multipath system.