How reliable are 2.5" external hard drives?

I'm seriously considering keeping all my files only on external hard drives.

My main computer is a laptop, and currently I back up the files on it to multiple external hard drives. I'm thinking of changing that, and keeping the files only on external drives. 2.5" drives in enclosures are small enough that it's not hard to carry two of them around and 320GB is cheap and more than enough for all of my files including pics and videos.

My only concern is reliability. Am I more likely to have a drive like a WD Passport or HP Simple Save fail than the drive in my laptop? Those are the two drives I've got right now, I carry them around in lightly padded cases inside a backback.

It comes down to:

• In general, are 2.5" drives in enclosures reliable enough to count on?
• Specifically, does carrying them around pose any significant extra risk?

Solution 1:

The problem with external enclosures is heat. Standard internal drives expect some ventilation, while external enclosures often seal the drive in with no forced ventilation.

If you want an external drive, it would be better to get something like the WD Passport, because it is already engineered with the intention for it to be used externally. Also, these types of external drives, being targeted for external use, will probably be engineered to withstand more bumping around than a standard internal drive(stuffed in an enclosure).

Now as far as your question about whether the external drive, or your laptop's hard drive is more reliable, I don't think can really be accurately answered. The best thing to do is assume either will fail at any time, and take precautions to protect your data! The problem with hard drives and reliability is it is very difficult to quantify or measure, and manufacturers generally have no incentive to invest in significant improvements to reliability. They can offer better capacity, RPM, and latency, in an effort to increase sales. However, increasing reliability through design and QA will cost them extra money and increase drive costs, and it is not something quantifiable that they can use to market and increase sales. So from one drive to the next, it's really hard to know what to expect.

Solution 2:

To answer your second question:

As long as the drive has been stopped properly (so the heads are "parked"), it's reasonably well padded and you don't throw it around or subject it to hard knocks then you should be OK carrying it around. As 2.5" drives are usually designed for laptops they should be robust enough.

There'll be nothing moving while the power is off so that won't be an issue.

To answer your first question:

I would have thought 2.5" driver enclosures would be reliable. I'd would go for a mid-price one - I object to paying top price for things and I'm always wary of the cheapest, they might have skimped on something important.

Solution 3:

A specific recommendation, good as of 22 Feb 2010:

Stay away from Seagate Momentus 5400.6 500 GB 2.5" drives. I've had 3 die in two different laptops in a 3 month span. (The 320 GB models have been working just fine for me.)

If you can stomach hauling them around, get desktop-sized external drives. They're generally cheaper per GB, and the drives are more reliable.