Since I am running the 2.6.6 kernel on my laptop now, I decided to take a look at laptop mode since it's included in the kernel now. The laptop-mode.txt readme that comes with the kernel has the approprate scripts in it, so I copied out the /sbin/laptop-mode script and ran it. I saw no mention of JFS support in the readme or the script however, so decided to go look on the net. The laptop mode page does say that JFS is supported, but thats it. Digging around on google got me a discussion about JFS and laptop mode on the JFS list. Looks like JFS didn't need any modifications to work with laptop mode, it just works. So, then I did a '/sbin/laptop-mode start' and a 'hdparm -S 4 /dev/hda' to set the spindown time on my drive low and start laptop mode. Nothing happened. To figure out what was keeping my drive spun up, I used: "echo 1 > /proc/sys/vm/block_dump". That spews out every process that hits the disk and if it's a read/write or a cache hit. Using that I fixed a few things: Set syslog to not sync after each log (a - before the filename), closed some firefox windows that were autorefreshing and writing to cache, setup syslog not to log my fetchnews jobs on each run. Tried laptop mode again, but it still wouldn't spin down. The drive was inactive as far as I could tell. Perhaps it's an issue with my drive somehow, so I looked around a bit more and pulled down smart_spindown which is a handy script that checks for activity and then spins down your drive if there isn't any. It has backoff so that if things seem busy it will wait longer and longer to spin it down. Using that script things spun down and appeared to work ok. Running it overnight I was able to see up to about 10min of spin down time at various points, sometimes as little as 30 seconds. I think this might be worth the savings if you were really hurting for power, but otherwise seems kinda pointless.