Recently a buddy of mine has pointed out in his blog (in Russian) that hard drives that use the ext3 filesystem can not be spun down because of the need to frequently write data. According to him, it is caused by the way the ext3 filesystem is implemented.
Is it actually true? Isn't there some way to use hard drive spin-down function when there is no data written and read from the disk? And by that I mean not some one-time manual spin-down, but a constantly running power-saving application of some sort.
It may be worth noting that I'm using Ubuntu, but it may be not that relevant to the matter.