RAID explained.
When it comes down to data storage, there are a few methods available which can help businesses and individuals ensure that their data is not only kept safe from unwanted people, but also kept safe from getting lost forever. After all, hard drives all have a limited lifespan and are all prone to failure at some point in their existence, so it is worth putting a strategy in place in the event of hardware failure.
Using RAID
Originally, when hard drives where more expensive, RAID was used as a way to combine cheaper low capacity hard drives into one higher capacity one. This is why RAID mainly stood for ‘Redundant Array of Inexpensive Disks’. As time went along, hard drives became cheaper, and RAID is now often understood as standing for ‘Redundant Array of Independent Disks’. By copying and spreading the data around those multiple drives, RAID offers a great fail safe in the advent of hardware failure.
Different levels of RAID
RAID has different levels at which the data gets stored together, the most commonly known levels of RAID used by individuals and businesses are RAID 0, RAID 1, RAID 5 and RAID 6.
RAID 0 is primarily used to increase the performance of the drives, spreading the data across different drives and allowing for increased write and read speeds. However RAID 0 does not duplicate the data across those drives, offering no protection against hard drive failure.
RAID 1 differs from that by writing and reading the data to pairs of drive, mirroring the data on each drive. This way if one of the drives fails, the data can still be accessed and stored onto the other mirrored drive. This a simple method of securing data, but it however means that a lot of hard drive space is being used, as the information is doubled in size.
This is where RAID 5 comes into place. Rather than just pairing two drives together, the mirroring information is spread across multiple drives in the array. This means that RAID 5 consumes less hard drive space when duplicating the information, leaving more room to store the data. However, and similarly to RAID 1, failure of a single disk can still lead to making our array vulnerable. All it will take from there is a second drive to fail and the data might potentially lost.
RAID 6 provides a second mirroring of the data, offering an extra layer of protection. This way, if the parity data gets lost on the faulty drive, a second set of paired data (also known as a parity stripe) is made available, ensuring that data isn’t lost. RAID 6 is the safest, but also most complicated and most expensive RAID method, as it uses more hard drive space.
RAID errors
Whilst RAID data storage offers a safer alternative to single drive storage by providing better backup of the data, drives in the array are still dependant from each other which means the array can still fail if one of the drive fails. If this occurs, the best thing is to call upon a professional services such as Kroll Ontrack RAID recovery to help put the array back together. Attempting to solve RAID issues without the expert knowledge of the professionals will only lead to losing the whole array, therefore losing all the data.
