It would always be nice to have some tool that can be used to find out the approximate life period remaining of your hard-drive. Well in newer SATA hard-drives they are using a Load/Unload mechanism for separating the disk and head. (detail explaination: http://www.linux-hero.com/rant/explanation-ubuntu-hard-drive-wear-and-tear).
In linux machines you can install 'smartmontools' to find out some interesting information about your hard-drive. This tool uses S.M.A.R.T (Self-Monitoring, Analysis and Reporting Technology) technology available in new hard-drives. This gives a specific count of Load/Unload done on your hard-disk. Normal hard-disk has 600,000 of Load/Unload cycles. Following is the method to find out the remaining life time of your hard-disk.
If you are a ubunbtu user like me simply give the following command:
sudo apt-get install smartmontools
It will install 'smartmontools' to your system. After than give the following command
sudo smartctl -d ata -a /dev/sda | grep '193'
It will show output something like this:
193 Load_Cycle_Count 0x0012 097 097 000 Old_age Always - 30385
Here in the last the number is 30,385 which is load/unload cycle count of my hard-drive. Well my drive is only 1.5 months old and it has already used 30,385 cycles.