1) What factors affect the life of a hard disk?
2) Does frequent writing on the disk reduce its life?
3) What is the average life span of a hard disk under normal condition?
4) Does less writing and more reading actions taking on the hard disk increase its life?
5) What way the virtual memory ( file paging ) on the disk effect its life ?
6) Is there any particular hard disk especially built for the excessive writing ?
Google actually did a big study on this. It is available here:
Eduardo Pinheiro, Wolf-Dietrich Weber and Luiz Andre Barroso
Failure Trends in a Large Disk Drive Population
From this report:
One of our key findings has been the lack of a consistent pattern of higher failure rates for higher temperature drives or for those drives at higher utilization levels. Such correlations have been repeatedly highlighted by previous studies, but we are unable to confirm them by observing our population.
[…]
Our results confirm the findings of previous smaller population studies that suggest that some of the SMART parameters are well-correlated with higher failure probabilities. We find, for example, that after their first scan error, drives are 39 times more likely to fail within 60 days than drives with no such errors. First errors in reallocations, offline reallocations, and probational counts are also strongly correlated to higher failure probabilities.
Biggest thing to do, really, is to keep those drives cool. Heat does a LOT more damage then just reading/writing.
Here's an interesting critique of the Google study:
http://www.quora.com/Hard-Drives/What-are-the-best-things-to-do-to-extend-the-life-of-my-hard-drive
Comment on linked paper: Saying that temperature and utilization doesn't seem to affect disk life may be misguided; figures 3, 4, and 5 tell a more obvious story: ~20% of consumer drives failed in the first year while used in a data center environment. -- Sub-20°C temperatures indicate cold/hot aisle containment (forcing cold air through the server racks), which is typical of data centers. Data center environments tend to be associated with higher utilization; figure 3 shows a high correlation between disk utilization and failure rate.
Anyways, his suggestions are this:
There are a number of things that can extend the life of the disk:
- Maintain a stable temperature that is within the manufacturer's
specified range (typically 5-60°C); heating and cooling cycles put
stress on the disk- Minimize rotation on axes parallel to the disk's platters (wears out the spindle bearings)
- Minimize the number of spin-up and spin-down cycles (puts stress on spindle bearings)
- Avoid shock and vibration that exceeds the manufacturer's
specificationsHowever, my personal philosophy is to hope for he best, plan for the worst, and to not let a $50 component dictate how I use my laptop. Instead, keep important data backed up, expect the disk to die within 2 years, replace the disk and battery when they die, and use the machine in the way that makes me feel the most comfortable. --It's a tool, not an investment!
