CMMVC8304E The system cannot apply the task because an earlier drive update task is still in progress.

Explanation
The svctask applydrivesoftware command is already running, and
only one instance of the command is allowed at a time.

User response
Try the command again when there is no drive update task in progress. Either use the
lsdriveupgradeprogress command to determine when the updates complete, or use the
svctask applydrivesoftware -cancel command to cancel the current drive update
task.