I know that you have to stop the motor when doing a hot-swap. What is the best way to do this? Can MHDD do this? Is there anything else to do when hot-swapping PCBs?

Thanks,

A

MHDD can stop spindle. Other tools, for example HDDScan also can.
It's a standard ATA command - Standby and there is nothing special about it.
For regular hot swap you don't have to do anything else. There is also another more powerful type of hot swap - smart hot swap. To do it you need to prepare donor first - copy translator modules and/or adaptives. This is quite dangerous procedure, it requires deep knowledge of firmware structure and can make donor drive inoperable.