Hardware

to keep external hard drives permanently connected. Connect it and use it and then use the safe removal proceedure. Don't leave the power supply connected and turned on either as this will shorten the life of the adaptor.

permanently connected to a Computer. The reason for this is that when you shut the computer off it doesn't close the external Drive correctly it just basically cuts the signal to it and this will sooner rather than latter result in the Partition Tables on the Drive being corrupted.

These devices need to be shut down with the Safely Remove Option under Windows and if you are using one of the Nix/BSD Platforms you need to Dismount the Drive before unplugging it.

If you leave a External HDD permanently connected to a computer it is running all of the time it is connected and generating Heat. This heat can not escape the enclosure correctly so it overheats the HDD and cause either the actual HDD itself or the Electronics inside the case to fail much sooner that would otherwise be the case. Ideally you should only use External Storage Devices like this when required and then remove them when they are not required.

If you need an External Drive permanently connected you need one of the enclosures with Active Cooling like the Antec MX1

http://www.antec.com/Believe_it/product.php?id=NDc=

These have a Fan in them to cool the HDD and prevent them overheating.

Also for Backup you should not only unplug the drive but should store it in a secure place when it's not in use. After all what good is a Backup in protecting you from Data Loss if it gets stolen/Damaged along with the computer that it is backing up?

Col