Mirror Hard drives
"The concept of mirroring is more of a productivity issue," says a representative from Maxtor.com. However, it is worth mentioning in relation to backups. Imagine that you've had a massive hard drive failure. What now? If you've used an external backup solution, you need to replace the hard drive, reinstall the operating system and the core software programs, and then move your data files back onto the new hard drive.
Pros: Mirroring provides a simpler solution. With mirroring, there are actually two or possibly three drives. When data is written to the hard disk, it is written to all three drives. This way, if one drive fails, you simply replace it with a working drive; your core files are all still there on the other drive(s). Over the next few days, the software that controls the mirror drives will copy files onto the new drive so a complete duplication of files once again exists on all drives. Thus, even though you've had a hard drive failure, you've had little to no downtime.
Cons: A mirror drive system will not protect your data in the case of fire or theft. For this reason, it is not presented as a viable back-up solution. However, it is a useful tool if you need to be up and running quickly should you experience a harddrive failure.
A word of caution: The software must be properly configured to ensure that both drives contain the appropriate data in case of a failure, and if there is a failure you'll need to be sure that the drive with the data writes to the one without, and not the other way around.
