I would read the documentation supplied by EMC regarding the updates.

Whether smitty update_all is the way to do it or not cannot tbe said in advance. If the update is sent as a tarball, for example, it may be the only change is to the Pd* ODM files - and then the command odmadd and/or odmchange, or some combinations may be needed. And, after updating the ODM you will need to consider whether you want to remove the Cu* entries and run cfgmgr to rediscover them with new defaults, or seperately run chdev commands to update to new settings.

regarding previous experience - I shall have to ask you to wait for others to reply. I know there are many people working with EMC storage on AIX and VIOS - so someone should be able to help you there.

Do you have a Dual VIOS setup with MPIO in the client partitions? If so, it will be much easier - and safer - to update your VIOS partitions.