==== Firmware upgrade ====

Follow always the same order for firmware upgrades:
  - first disks DDM
  - second ESM drawers
  - third controllers (at same time NVRAM and controllers)

Controller upgrade can be done On Line unless otherwise stated \\
All other components require partial downtime\\
Fail over driver, HBA firmware upgrade require related server downtime\\
ESM firmware requires stopping IO’s to related EXP\\
Drive firmware requires stoppins IO’s to related volume group\\
Risk of data loss if  being performed incorrectly