How RAID Hardware Can Aid Data Recovery

If you are a business or home computer user with large volumes of data to archive, a RAID drive unit may be the best way to store backed up data. There is a lot of information available online to explain the function of RAID drives. However, the topic tends to be quite complex. There are many different RAID configurations and it can be hard to find articles that break everything down in a way that’s easy to understand.

If you’re interested in finding out more about RAID and how it can help you in the event of a data recovery scenario, you could speak with a specialist in RAID data recovery in NJ or any US state. An expert in working with RAID drives will be able to explain and demonstrate the concept in an understandable fashion. This article may also help you understand RAID drives by answering a number of typical questions on the topic.

What is RAID?

RAID is an acronym for a Redundant Array of Independent Disks. A RAID drive is therefore a unit of computer hardware housing a number of independent disk drives. Essentially a RAID drive can be a number of standard hard drives, each one standing alone and all of them linked to a controller, which allows them to work together in an array. In most cases though, the drives will be housed discretely within a casing.  So if you buy a RAID drive, what you’ll physically get is a single piece of hardware, which houses numerous drives. The whole thing will connect to your computer via a USB or similar type of connection.

Why Would I Purchase a RAID Drive?

There are two main reasons you might buy and use a RAID drive.

1) If you need very fast data processing.

2) If you need a degree of redundancy to protect data and facilitate data recovery.

Redundancy simply means that multiple drives work together and, should one drive fail, the others take over its work. As an analogy, consider an airliner with four engines. The reason the airliner has so many engines is to protect the passengers and crew in the event of engine failure. An airliner can still fly even if three of the four engines were to fail; an extremely unlikely scenario.

A RAID drive then, is like having two, three or four engines to protect your data. Even if one or more of the drives should fail, data recovery is still possible via the remaining drives. This is the most common reason for computer users to purchase a RAID drive.

There are numerous configurations for RAID drives and this is the part that can get confusing if you’re not technically minded.

Why Are There So Many RAID Configurations?

The different configurations make RAID drives suitable for various situations. A lot depends on what’s required in terms of data access speed and redundancy. For example:

RAID 0 is a configuration which provides fast access to data but no redundancy
RAID 1 configuration provides redundancy, but is slow
RAID 5 is a configuration which provides a balance between faster access and a level of redundancy

Most experts on RAID data recovery in NJ would probably recommend RAID 5 as a good solution for home and small business data backup and storage.

How Do These RAID Configurations Differ?

RAID 0 is a configuration in which data is alternately written or read between one drive and then another. This is called “striping”. Striping can result in a computer file being partially written onto one drive and partially onto another. If one of those two drives fails, the file will be partially lost, meaning you could only retrieve that file with the help of professional data recovery. Striping is a fast way of accessing and writing data using multiple drives, but has no redundancy to protect data written across them.

RAID 1 is pretty much the opposite of RAID 0, in that data is duplicated on each of two drives. There is no striping. The two drives are mirrors of each other and contain exactly the same data. If one drive fails, data is not lost because it has been copied onto the second drive. That’s why RAID 1 is slow, but very good in a data recovery situation.

RAID 5 combines the best of RAID 0 and RAID 1 but requires a minimum of three independent drives in the array. In a RAID 5 configuration, the data is striped across two drives, with the third drive holding what’s known as “parity” information. Parity information is extra data, created by a RAID controller and written to the third disk in the array. This information is makes it possible to reconstruct files in the event that one of the drives should fail.

So in RAID 5, if drive one or two should fail, the parity information in drive 3 enables the controller to reconstruct missing data from the failed drive. In practice, this happens on the fly, so you wouldn’t necessarily know that a drive had failed. Your data would remain intact and you might only experience a loss of speed. With RAID 5 you benefit in terms of data access speed, due to striping and also have total redundancy in the event of one drive failing in the array.

What If Two Drives Fail?

The simultaneous failure of two drives is extremely unlikely. Returning to the airliner analogy, the chances of two simultaneous engine failures are very slim. This is why many airliners have only two engines. Similarly, for most uses, three drives in a RAID configuration are sufficient. One drive holds parity information, so if either of the others should fail, data is reconstructed.

Of course, in the very unlikely event of two simultaneous drive failures, you would lose access to your data and would need to call in a New Jersey data recovery service to rescue your files from the dead drives.

If you are having a problem with your RAID drive and think one of the disks may have failed, the team at Dave’s Computers will check your drive and make sure it’s fixed before you risk a data loss. Check-in with them to discuss your RAID issues on 908-428-9558.

by David Molnar

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