Change idle spindown time on the HD
hdparm [ flags ] [device] are used to set the time the harddisk must be idle, before it spins down.
This sets the idle time to one hour:
hdparm -S242 /dev/sda
Values of -S: 0 Disable spin down 1 - 240 Value times 5 secs (1=5 240=20 min) 241 - 251 Value-240 times 30 min. (241=30min. 251=5,5 hours) above are special and reserved. Se man pages.
To se if the drive are active or in standby:
hdparm -C /dev/sda
To list disks and there partitions:
fdisk -l
NB 1: Dont set the idle time to low. Spin-up wares the disk out.
NB 2: Don't play around with hdparm. It writes directly in the HD controler registers. You can destroy the disk.