What Does "MTBF" (Mean Time Before Failure) Actually Mean?

[Jonny_Quick]

I'm shopping for a Hard Drive and noticed on the specifications that one of the drives claims it has "2 million hours" of MTBF, and so I take 2,000,000 divided by 24 hours equals 83,333 days divided by 365 days (in a year) equals 228.3 years, and yeah I call bullshit, because there is NO WAY that any hard drive is going to last 228 years.

So, then what does it mean, and how long will a hard drive last that is spec'd at "2 million hours"?

[fzabkar]

It is the average time between failures in a large population of drives. In your example, a population of 1000 drives can expect a failure every 2000 hours (2 million hours / 1000).

[Hardcore Games]

https://en.wikipedia.org/wiki/Mean_time ... n_failures

Helium disks have more platters as the friction is lower. Servers with millions of disks can use MTBF to estimate how many spare drives will be needed before a forklift upgrade is needed.

[HaQue]

https://en.wikipedia.org/wiki/Mean_time_between_failures

Helium disks have more platters as the friction is lower. Servers with millions of disks can use MTBF to estimate how many spare drives will be needed before a forklift upgrade is needed.

Not sure how upgrading server with forklifts would work... is this because they 'hold' more data? or because you 'drive' a foklift? Storage on Pallets instead of platters is an interesting Idea, but I have not heard of drives coming from CHEP or Loscam as yet. Also would be quite cumbersome for a home user. Bunnings could store a lot on their shelves, maybe they are the next Data Centre?