What is best for external HDD health?

(1) Stored switched off and unplugged from electricity (except when actively using it to back up the system, of course).
(2) Stored switched off and plugged into electricity.
(3) Stored switched on.
(4) Makes no difference.

I have an external Iomega HDD I use for backing up my system. It's got a power switch on the back, and I'm just not sure what I should be doing with it long term.

 

At the very least, you should make sure the drive doesn't spin when it's not in use. Aside from that, i don't think leaving it plugged in or unplugged matters much.

 

Mitlov, Good question, I do option 1 because I store the hard drive at my neighbors home.
With option 2 & 3 there is always the remote possibility of a power surge

 

I keep it on and plugged in all the time.
With the current price of external HDD, they are more like "disposable" now.

However, I always turn my entire system off when not in use (by flicking the surge protector switch)

 

Any external case these days worth its salt should power off the hard drive when not in use, so it really doesn't matter.

 

Curiously, when I used my external HDD with my MBP (backing up through OSX's time machine function), it'd go completely silent when disconnected from the computer. Now that I'm using it to back up with my Vaio (backing up through Windows' backup function), even if I eject the HDD via the taskbar before pulling the USB connection, it still has a low hum, like a cooling fan at idle or a slow spin of the HDD (not sure which it is). So now I flip it off after unplugging it from the computer.

The point another poster raised about a serious power surge is a good one; I might start unplugging it from the wall even after switching it off.

 

Speaking in general terms of hard drives, the greatest threat to your data is damage from physical shock (dropping it or knocking it over). And in those cases, a drive that is powered off will have a better chance of surviving than a drive that is powered on when it is dropped.


For your specific situation, I'd say leave the drive plugged in and powered on. In your specific situation, the greatest threat to your data is that you forget to turn on the drive before a scheduled backup (or worse, you don't have an automated schedule at all). So leave the drive plugged in, and set to run on an automated schedule, and you should be fine. The threat of damage from physical shock or power surge is minuscule compared to the threat of human error.

 

For the danger of a power surge, who doesn't plug their gear in a surge protector when they are at home anyways? .

 

I have an "Western Digital Elements 2 TB External" and it is powered on 16 hours of the day, but it automatically powers itself down if you do not access it for 15mins or so, but as soon as you click on the drive it wakes up, I have been using it for over a year, and it still has a perfect smart score.

I unplug it all the time without ejecting it without any problems, just dont do it when it writing data and you will be fine.