套件： hd-idle (1.05+ds-2)

Spin down idle [USB] hard disks

hd-idle is a utility program for spinning-down external disks after a period of idle time. Since most external IDE disk enclosures don't support setting the IDE idle timer, a program like hd-idle is required to spin down idle disks automatically.

A word of caution: hard disks don't like spinning up too often. Laptop disks are more robust in this respect than desktop disks but if you set your disks to spin down after a few seconds you may damage the disk over time due to the stress the spin-up causes on the spindle motor and bearings. It seems that manufacturers recommend a minimum idle time of 3-5 minutes, the default in hd-idle is 10 minutes.

One more word of caution: hd-idle will spin down any disk accessible via the SCSI layer (USB, IEEE1394, ...) but it will not work with real SCSI disks because they don't spin up automatically. Thus it's not called scsi-idle and It is not recommended to use it on a real SCSI system unless you have a kernel patch that automatically starts the SCSI disks after receiving a sense buffer indicating the disk has been stopped. Without such a patch, real SCSI disks won't start again and you can as well pull the plug.