Debian provides scsitools. For example scsi-spin to spin down scsi-drives. Could someone provide an ebuild for that?
Go and use sys-apps/sg3_utils instead. Debian's scsi-tools is targeted towards a 2.2 kernel (shudder). sg3_utils provides the up to date version of this stuff. sg_start provides the spindown if you need it.
*** Bug 167350 has been marked as a duplicate of this bug. ***