I have to upgrade a OES2SP0-cluster (linux-based) to SP2a, but I guess
my question is relevant for all kernel updates, also:

my experience from installing a kernel update is, that a new initrd will
be created, which kicks out all manually installed/compiled drivers.

Background: I had to use manually compiled drivers to activate RDAC
support to connect the servers to the SAN using 2 HBAs for each server
(multipath). At least at this time it had been the only known option to
do this, because the standard multipath tools do not support IBM DS3x00

When the server boots up after installing a kernel update, it loads the
new initrd and therefor does load the standard HBA drivers and no RDAC
drivers. This causes cluster services to fail loading, because it does
not find the Cluster Partition and so on. I can recompile/install the
modified HBA drivers and RDAC drivers and after the next bootup
everything is fine again.

But: is this really the way to do this? Can I be sure that SLES/OES does
not touch the SAN partitions (which are in use be the other cluster
node!) at all and does not cause any trouble?

Or which way is the "right" way to perform such updates?

Any advice and experiences are appreciated.

Note: disconnecting the server from the SAN is no option, because RDAC
needs communication with the SAN during installtion

Thanks in advance,