[CentOS] question on modules loaded

Fri Mar 11 17:14:45 UTC 2011
Jerry Geis <geisj at pagestation.com>

lsmod shows

dm_raid45              66509  0
dm_message              6977  1 dm_raid45
dm_region_hash         15681  1 dm_raid45
dm_log                 14529  3 dm_mirror,dm_raid45,dm_region_hash
dm_mod                 62201  4 dm_mirror,dm_multipath,dm_raid45,dm_log
dm_mem_cache            9537  1 dm_raid45


I am wondering why these raid modules are loaded as I am not running 
raid on this
particular machine and looking for ways to free up memory.

THanks,

jerry