HDD activity

Hi, I have running 4 SuSE linux boxes with 8.0, the FS are ext2 in some machines and RaiserFS in others. I noticed time ago there was HDD access every 20 secs +/-, but I dont care in that moment, now I install 8.0 on a Laptop IBM thinkpad 600 and I have the same activity oin disks, but in this case this cause battery to go down shorter, so I want to know if anybody knows which process cause this hard thisk activity and if it can be removed. Thanks -- Jorge informes@intraredes.com http://www.intraredes.com