How long will my Bubba HDD last?
So, your bubba have been running for a couple of years, how long will it last?
There is not easy answer to that question :(
WD (Excito's main HDD vendor) used to quote 30,000 hours of MTBF. But all that really means is that if you had a large sample of drives, half of them would be broken after 3.4 years.
Another example, using Googles "real world" AFR data (link 2 below), the AFR for the different disk ages:
So if you have a server room with 1000 disk, you could expect 1.7% (or a total of 17) of them to be broken after year, a total of 96 after 2 years etc...
- A HDD vendor can't guarantee how long a single using will last, it's all statistical data. This data is only really meaningfull if you have a big array of disks, and doesn't apply very well (with great level of certainty) to your single datapoint (your bubba).
- Disk MTBF numbers significantly understate failure rates.
- Consider replacing 3 year old disks, or at least get serious about back up.
- SmartMonTools will alert you to some issues, but not most
- High/low usage and ambient temperature doesn't have a massive impact on HDD life
- Most importantly Remember to always backup data you care about (pictures, docs, hg repos etc).
Rule of thumb I use is to have them on three places, and all of them can't be in the same geographical spot (not all in same closet in the same house!) :-)
- WC Official Statement
- Google's Experiences of BIG disk arrays
- Why big MTBF numbers are pointless
- More on MTBF