Hard drive spin up before shutting down

[joninator6]

Shouldn't drives be spun down before shutting down? I always thought that it's bad for the drives to turn off while spinning. So, how come unraid always spins the drives up before shutting down?

[JonathanM]

Can you cite a source? In my 40+ some odd years of tech, I've never heard that. As a matter of fact, some drives even used the rotational energy of the platters to park the heads if power is pulled while the drive is spinning.

 

As to why Unraid spins up the drives, it's to cleanly unmount the file systems, which are kept mounted while the drives are allowed to spin down if not accessed for a set period of time during normal use. Unmounting the filesystems requires the drives to be accessed.

[JorgeB]

Also drives will spin down on shutdown dependent on the controller connected, if for example you have 6 drives connected to an Intel SATA controller and the rest to an LSI HBA on power down you'll hear the 6 drives on the Intel controllers powering down/spinning down one by one and then the computer will power off shutting down the remaining ones on the LSI while running, either way never found it an actual issue or reliability problem.