Points to Note in Servicing concerning Mirroring Functionality
The modes other than Mirror Mode indicate troubles, which require swift recovery.
The power can be turned OFF even during Rebuild process. However, it is recommended not to turn off the power and wait until the mode flows to Mirror Mode. In addition, HDD removal after power-OFF is guaranteed only in Mirror Mode.
The mirroring PCB controls Master HDD and Backup HDD. This control is performed based on the HDD serial number and the model serial number instead of slot locations.
If HDDs are replaced in a careless manner during servicing in the field, the Master and Backup HDDs may be switched.
When the master HDD is in trouble, the mirroring PCB automatically recognizes the backup HDD as the master. Thus, the master and backup HDDs are switched even without changing the slot locations.
If the Master HDD cannot be located, turn OFF/ ON the power to check on which channel the green LED is lit on the LED PCB. The firstly-blinked LED (Ch A/Ch B) shows the Master HDD, which is accessed firstly after power-on.
For users who intend to use the removable and mirroring functionality concurrently, instruct them not to change the removable HDD location in advance.
Change of HDD locations after power-OFF is allowed as specifications only in Mirror Mode.
Otherwise, HDD removal or change of location is not guaranteed.
The following conditions are required to replace HDDs at power-ON.
Removable HDD is extended
Either HDD is in trouble
CAUTION:
Be sure to use a new HDD when replacing the HDD.
Upgrading should be done only in Mirror Mode while mirroring in ongoing. Upgrading in Degrade/Rebuild mode is basically prohibited. Always prioritize Mirror Mode when you take any actions.