Under what conditions should the 'start_udev' command be run?

Issue

• We run start_udev as part of the storage allocation procedure that we have. It works, but it can be disruptive if an oracle DB instance is up and running (the listener interfaces briefly disappear). Our RH versions that we certified for SAN are 4u5, 4u8, 5.4 and 5.5.

• If we don't run it, we don't get the multipath aliases show up in /dev/mapper directory - just the WWIDs.

• The SAN folks want to know under what circumstances should start_udev be run?