USB HDDを効率的に停止する。  USB HDDを効率的に停止する。

NSLU2-Linux - FAQ / SpinDownUSBHarddisks browse

"Shell-only scsi-idle without kernel patch"の部分がよさげです。

#!/bin/sh

disk=$1
interval=$2

state=`grep " $disk " /proc/diskstats`
count=$interval
up=1

while [ true ]; do
   sleep 10
   count=$(($count-10))
   newstate=`grep " $disk " /proc/diskstats`
   if [ "$state" = "$newstate" ]; then
      if [ $count -lt 0 ]; then
         count=$interval
         if [ $up = 1 ]; then
            #echo -e "spin-down\\t" `date`
            sync
            state=`grep " $disk " /proc/diskstats`
            scsi-stop /dev/$disk
            up=0
         fi
      fi
   else
      #echo -e "drive is up\\t" `date`
      count=$interval
      state="$newstate"
      up=1
   fi
done