I have a very large home data base just shy of one terabyte and expected to be close to 2 terabytes by the end of this summer, I enjoy the portability and the limitless expandability of USB 2.0 hardware but with great hardware comes great responsibility.I have had at least 6 external hard disks in the past few years and at least 2 of them have failed.  So what causes all these problems and what did I do to learn from my mistakes?  There are a lot of factors involved in deciding on a hard drive enclosure many of which actually affect the longevity of the drives you put into them many of these include heat dissipation and head parking protocal.

At least 90% of all enclosures available today do not provide sufficient heat dissipation, this is has largely to do with the simple fact that hard drives were never originally designed to be couped up in an enclusre that provides nearly no if any clearance on any side of the drive.  In a normal scenario a drive is in a computer case where there is at least enough airflow to allow the drives to to stay below critical temperatures.  When these enclosures first hit the market a lot of them were made of plastic because this problem was not anticipated liek it should have been.  The new enclosures are generally made of alluminum but even such they are often failrly poor heat sinks.  Unfortunately a fan cooled enclosre can be up to 5 times the cost of a non fan cooled enclosure so what is a budget savvy consumer to do?  Buy the alluminum hard drive coolers there are countless types and they are cheap many of which can be modified to accomadate the outside of your enclusure and make sure whatever it is that it has fans.  Heat is the number 2 killer of hard drives as too much heat will warp the disks and this is a recipe for disaster.  This can only be determined using highly specialised equipment as the warping usuing is in the 100ths of an inch.

A much more important factor is how the drives are parked and removed,  Most enclossures have a built in switch to shut the drive off when they are safely removed in windows remember to safely remove by the way.  If the drive is extremely loud upon shutting down this means the drive has parked the heads to fast and this can scratch the fragile disks corrupting data and causing havoc on the physical drive.  If this happens return the enclosure its nopt worth sacrificing the drive for.