We must send either an IDLE IMMEDIATE or a STANDBY IMMEDIATE to drives
on warm boot so their SMART and other volatile data is
persisted. However, for a warm boot we don't want to send STANDBY
IMMEDIATE to some spinning drives because they will spin down. If
there's a lot of these drives on the system, that can cause a thunding
heard problem at startup time (that in extreme cases causes timeout in
device discovery).
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