Dear Aunt TUAW: What is the lifespan of a large-capacity hard drive?

Backups ahh backups. When figuring out a backup plan it is worth taking stock of what, exactly, you are backing up. For example: Do I need to backup my Steam game library? Hell no! It's 16+ Gb of stuff I can just download again. All my documents & photo's obviously they need backing up.

Once you get ruthless with what is/isn't essential for backup you often end up pairing multi-TB arrays down to 1 or 2 DVD-R's or a single tape's worth of important stuff. Which frankly is much more manageable.

As to how long the shiniest of shiny drives will last? 3 years of constant rotation is about the norm for a consumer device. Obviously if the drive is spun up, backed up to then, turned off it will appear to have a much longer lifespan. In such cases keeping the occasional eye on the SMART status can be handy, it will list the rotational hours.

The URL of the Google paper seems to be too long; this is the short one:

http://goo.gl/iOo33

Recently Google published a paper about drive reliability and operation time to failure in their drive fleet:

http://static.googleusercontent.com/external_content/untrusted_dlcp/labs.google.com/nl//papers/disk_failures.pdf

This paper shows a nice scientific and non-vendor based insight into drive reliability. Your 18 months is not far off, after reading this article I am planning to retire my hard drives every 2 years. New to me was that higher operation temperatures (30-45 C) did not affect the drives in any way but lower temperatures did.

Don't be concerned with drive lifespans, and don't think you're doing yourself a favor by replacing your drives after 18 months. Inevitably you will have a drive that dies after, say, 9 months; and then if you don't have a decent backup plan in place, you'll be sunk.

By "a decent backup plan" I mean: (1) backing up all of your computers regularly, and (2) making a monthly or weekly backup of the backup and storing it off-site.

For backing up all of your computers regularly, a NAS that supports Time Machine is a good idea. But that can't be your only backup - what if your computer *and* the backup both fall victim to thieves or fire? That's why you need to occasionally back up your NAS to an external USB hard drive, and store that drive in a friend's safe.

My media collection could easily fill an 8 Terabyte drive. At least once I get my discs backed up on them. We have over 800 Bluray and DvD movies plus another 300 VHS movies that need to be replaced with digital copies.

From the horses mouth so to speak: http://www.engadget.com/2007/02/18/massive-google-hard-drive-survey-turns-up-very-interesting-thing/

Google did a report on the drives in their data centers and Google only uses COTS drives which I have to assume are not explicitly "enterprise" level drives. Basically it doesn't matter, drives fail but as a general rule drives that are brand new or very old fail more. Remember all electronics are fundamentally light bulbs, they will burn out it just depends on how long they last before they do.

From my own experience managing two SAN devices, one with 16Tb (16 x 1Tb drives) and the other with 32Tb (16x 2Tb drives) I have seen the following. The 16Tb SAN used only COTS 1Tb drives, nothing special and they fail almost exactly at the end of their rated lifespan, 3 years. The 32Tb SAN, which was upgraded from 1Tb drives, uses only "enterprise" class drives of which even the original 1Tb drives that have been re-purposed are still working fine after close to 5+ years of use on the 1Tb drives. I haven't had a single 2Tb drive failure yet.

Enterprise class drives do have a higher MTBF and are built better than COTS drives. Would I replace a drive every 18 months 'just cause'? No I wouldn't that's just dumb, what I would do if I was really worried about data integrity is use the right drive in the first place. More to the point I'd get an external enclosure that allows RAID 5 (which is not a back up but rather insurance against a failure) and then buy 5 similar drives, 4 to use and 1 to keep as a cold spare. If your really paranoid buy the 5 drives from 5 retailers to give you a better chance of not getting 5 drives made in sequence so that if there is a manufacturing issue it hopefully wont affect all 5 drives.

The question that you need to ask is are the manufactures of these 8Tb arrays using a COTS drive or an Enterprise drive in the enclosure? If you don't know then build your own, it's not that much more cost wise and you'll be assured that you have the best chance of data survival.

I'd like tuaw to do a writeup on drobo at some point, it simply blows all other raid and nas solutions out of the water. Apple should offer to buy these guys out with their warchest and include the BeyondRaid system into their macpros and timemachines.

Call me a conspiracy theorist, but the problem with ALMOST EVERYTHING manufactured these days is that they are no longer meant to last. When they say, "they don't make them like they used to," it's because it's in the company's best interest not to. If they made a product that would last forever, they'd only sell it to you once. If they force in a shortened lifespan, they know that you'll return to them. The magic, of course, is determining what is too short before they think you're too unreliable or not worth it, and too long that they won't get repeat sales soon enough.

From personal experiance i can only reccomend one storage system... Drobo. Through the years i have had many drives and a few failures, usually with very bad results, unrecoverable data due to a large storage space being spread over multiple drives. Example and point here was my lacie big disk. One drive failed and i lost everything. I couldn't send it to lacie as they would only fix the drive, not make an attempt to recover the data. I then sent it to a data recovery specialist. No recovery no charge. Unfortunatly i wasn't charged, they even tried writing custom firmware but to no avail. At this point i lost 5 years worth of graphics work, bad way to learn my lesson. 6 months later and a lot of requesting previous print jobs from printers the drobo launched. From the launch of drobo i have been using their 4 bay usb model and its still happily chugging away. It gets transported every day, suffered multiple bangs and its fine. I have 2 1 terabyte drives in there and have suffered 2 drive failures to date. Simple matter of whipping out the drive, sending it back to the manufacturer and haveing replacement sent back under warrenty and just plug in. Haven't lost a single file yet! There is still room for two more drives of any size and long term id say i'll save money. I only have to buy internal hd's at a low cost. I may upgrade to a network version soon, maybe they will introduce thunderbolt also. They are not expensive when you consider that data recovery on a drive can cost you up to £600.

I use Drobo and recently cycled 2 of the 1Tb 3yr old drives out for shiny new 2Tb Caviar Blacks with 64Mb cache. I would err towards decent quality drives and run them for 3 years in this configuration but mine stay on all the time and don't potentially suffer from inbuilt spin-up counter issues that you get in a lot of drives these days.

The larger capacity drives do interest me though because instead of tape I use a SATA caddy and just drop my retired drives into that as backup media but it means I have to spit my data sets across several different drives. Once the backup is done though the drives go into antistatic bags and put in a safe place