Set with a URL (e.g. 'flash:/filename.rel' or
'card:/filename.rel') to save the currently running software to
the root of flash or SD card. Only one save operation can be
executed at a time across all SNMP users, and an operation may
not be started unless the current value of currSoftSaveStatus
is 'idle'. The URL must not contain whitespace characters.
Immediately upon executing the set action, the actual firmware
save operation will be started and continue on the device until
it has completed or a failure occurs. The current status of the
operation can be determined by reading currSoftSaveStatus, and
the result of the last completed operation is indicated by
currSoftLastSaveResult.
When read, this object will return the URL of the last
firmware save operation that was attempted.