Should I keep an external hard drive permanently connected?

December 1, 2004 7:40 AM

Hey, is it better to keep an external hard drive plugged into and constantly running, or is it safer (for archiving and the health of the drive, avoiding power failures that might otherwise zap an entire machine, etc) to only turn it on and connect it when you use it? Thanks as always for your thoughts.
posted by Peter H to Education (12 answers total)

I always plug mine in only when I need it, as I use it for a backup, I'm paranoid about viruses, and operate on the theory that the best firewall is air.
posted by luser at 8:05 AM on December 1, 2004

I've had my LaCie 120GB drive for going on two years, and I keep mine on whenever my computer's on, which is basically all of the time, and it's used constantly because it's where I keep my iTunes library. I've never had any problems, even when my electricity's going out suddenly.
posted by bitpart at 8:09 AM on December 1, 2004

if it's for backups then you should leave it unconnected/switched off when not in use (and preferably in another building/city/country). what you're trying to avoid is losing both copies of data at once - be that from a bomb, hackers, power spike, viruses, whatever.

if you just want long life, it probably depends on the quality of your power supply, how well made the disk is, and what the operating system does (ie lots of fiddly details).
posted by andrew cooke at 8:10 AM on December 1, 2004

Response by poster: Yeah, it's for backup. Thank you for the replies, confirms my thoughts on what to do.

One concern, though - aren't hard drives supposed to be spun relatively often? Does this still apply to modern drives? Thanks again for the answers.
posted by Peter H at 9:26 AM on December 1, 2004

My Ximeta 160Gig NAS/Fire/USB external died about a month after the 1 year warranty. It was always on (no power switch), and never moved from my desk from the first time I turned it on. I cracked the case (after Ximeta denied the warranty replacement) to find the aluminum case that I assumed acted as a heatsink was not designed to make contact with the crappy Samsung HD they used. Upon closer inspection the overheated, endlessly spinning drive threw a bearing that got caught by the head and scarred the disk.

I have a LaCie 30Gig USB1.0/Fire400 that I've had for almost 3 years. It travels everywhere I go, and shows it's age cosmetically. However it fires up every time no problem.

I replaced the Ximeta with a new LaCie 200 Gig model Fire800/Fire400/USB 2.0. It comes on with the PC boot, but I turn it off unless it is to be used. No need for this drive to be spinning unless it is being read/written to.

LaCie rocks! [IMHO]
posted by HyperBlue at 10:17 AM on December 1, 2004

Yikes! I have a switched Ximeta 120G on my network. I will keep shutting it off when I don't need it. Also I'm with luser "the best firewall...."
posted by Hash at 10:33 AM on December 1, 2004

If it's for backup purposes, keep it in a safe place (as mentioned before)

Like all mechanical devices, if left alone for too long, the bearings could indeed seize, but a long time is a year or more... not once a month or a week, increments in which I'm assuming you do your backups.
posted by defcom1 at 10:45 AM on December 1, 2004

my generations-old lacie at work stays on for days on end, takes all kinds of abuse (not physical), and has never wavered. may my sleek and beauteous new personal 250gb be the same.
posted by ism at 12:51 PM on December 1, 2004

Bear in mind that if the drive wears out, you can probably just get a standard IDE drive and swap it out in the same case. There's usually no reason to pay extra for an "external" drive.
posted by Caviar at 1:48 PM on December 1, 2004

I have a Western Digital 200GB combo drive, and I leave it on pretty much 24/7. Since there's no power switch, I'm too lazy to unplug the thing, as the power cord often falls down behind my desk and I have to go get it. Haven't had any problems so far, so hopefully this won't bite me in the end...
posted by swank6 at 9:30 PM on December 1, 2004

Remember that hard disks are rated for enormous MTBF's: Mean Time Before Failure. One of these puppies I know can do 500,000 hours.

Math? That's 20,800 days. 57 Years. Continuously. Yeah.

An external disk will be subject to less heat than internal, so you can run it and start it / stop it as often as you like.

Hard disks already have thermal expansion and contraction designed into them- they have to do this in order for the data to be consistently written and read.

So, if it's for backup, use it only when you back up. If it's for storage, hook the fucker up and enjoy!
posted by id at 3:25 AM on December 2, 2004

As someone who goes through hard drives like paper plates, I urge you not to assume that any hard drive is going to last 57 years! Mean Time Before Failure refers to the chance of a failure in a set of identical drives, not any single drive. A MTBF of 500,000 hours means that 1000 drives ran for 500 hours before one failed.
posted by Yogurt at 2:10 PM on December 2, 2004