Buying an External Hard drive: What you need to know!

With the prices external drives decreasing year per year and with the increasing demand in storing the data the need of buying external storage systems is a hot item nowadays. It’s an inexpensive way of increasing your storage capacity and performance or just getting on the safe side increasing your data security and back up. Just like companies think about redundancy and backup their data you are able to buy a external hard drive as a great backup solution.

External Hard drives: Raid Systems

Often external hard drives are raid systems and the problem is that they are not recognisable as such by a end consumer. The main reason for this is that they are sold as “normal” external hard drives. These external hard drives offer a large capacity 500 GB 1 TB, 1.5 TB 2 TB and they are sold as a cheap back up solution. Now without the consumer knowing it they then buy the system and are not aware of for example how many drives there are in the actual system. To give you a clear example you can buy a LaCie 1 TB external hard drive which can have 2x 500GB or 4x 250 GB hard drives. Another problem that a end consumer can face is with the setup of the Raid system. An external hard drive system can have a different bandwidth or parity if you buy a Maxtor, or a LaCie or an Iomega system. These things always come to play in case of a data loss. Then you are faced with losing all your files and you are suddenly aware that your backup solution was not a great solution at all.

Raid System explained:

The definition of Raid is still valid. Raid stands for Redundant Array of inexpensive Disks. There a two group based on they way of writing the data to the external hard drives namely

1.Striping:

The data is written in on both drives on the same time. You will notice that you have a stripe raid system when you have a logical volume that is the same size as the amount of GB of the external hard drive. This does not apply for external storage arrays with only 1 hard drive. Striping can also be identified as a RAID 0.

2.Mirroring:

The same data is written on the 2 hard drives at the same time. Basically you have 1 hard drive that is an exact copy of the other and that means that if you delete a file you also delete the file at the same time. You will notice if you have a mirror raid system when you have a logical volume that is half the size as the total amount of GB of the external hard drive. Mirroring can be also identified as a RAID 1.

3.RAID 5 Special attention:

Most external hard drives with more than 3 hard drives can also be used for a Raid 5 setup. There are called NAS systems and can be used as a network storage backup drive. RAID 5 uses the high performance capability of striping with the increased integrity of the parity bit By comparing the data on two of the drives, it can "fill in the blanks" on the third drive, just like solving an mathematic equation. You will notice if you have a raid 5 system when you have a logical volume that is third of the size as the total amount of GB of the external hard drive.(NAS)

Final Advice:

The one thing you have to remember is when you buy an external hard drive is to ask yourself the following question: What kind of system am I buying? Be absolutely sure of what kind of Raid system you want to use and for what purpose. Last but not least make sure you always have your data stored in at least two different media at the same time.