HP A3550A - High Availability Disk Arrays Model 20 Storage Enclosure User Manual page 212

Table 5-12 Firmware Update Tool Menu Items and Descriptions
Menu Item Option
Update Controller
Firmware
Disk Firmware
5-40 Support Tools Manager (STM)
Property Description
Download, Downloads microcode to the disk array's database
update PROM drives, burns PROM code contained in the download
and restart file to the SP's PROMs, and restarts the SP using the
controllers new microcode.
Download and Downloads microcode to the disk array's database
restart drives and restarts the SP using the new microcode.
controllers
Download only Downloads microcode to the disk array's database
drives, but does not take effect until the SPs are
restarted (with a Restart Controllers only command,
or by power cycling the disk array).
Restart Restarts the SPs, using microcode residing on the
controllers only database drives.
N/A Supplies firmware to all compatible disk modules
within the disk array (that is, those with the same
product ID). This applies even to disk modules
owned by another SP. The firmware then resides
permanently within those disk modules until another
disk module firmware update is performed.