How Do RAID Levels Store Data?
Essentially, a RAID level is a basic set of RAID configurations that use one of three possible techniques for reading and writing data from computer hard drives. These techniques are striping, mirroring, and parity.
In a striping configuration, the disks have a predefined number of contiguous disk blocks that are called strips. When these strips are aligned in multiple disks, they are called stripes. In this format, one file of information is broken up and the pieces are stored across each of the disks in the drive.
Mirroring is the replication of data to at least two disks. Each disk in the configuration is the exact copy of the other, making it easier to continue using the RAID after a disk failure. Mirroring is advantageous for those who require high performance and fast availability. Read operations are fast because data can be read from the disks simultaneously, but write operations are considerably slower because all data is copied to each drive.
Parity is a way to have full protection for your data without having a complete duplicate of your information. For example, in a four disk configuration, three disks would contain individual data, while the fourth would contain the sum of each of those disks. In the event that a disk would fail, the parity disk would be able to make up whatever data was lost on that particular disk.
Get On My Storage Level
There are five commonly used RAID levels that use one of the above configurations, or in some cases will use a combination of them. These are RAID 0, 1, 5, 6, and 10.
This format uses striping and only offers high performance. There are an even number of drives and data is striped across them equally. They are great for video streaming, editing, gaming and other high-speed applications but are not useful for redundancy or long-term storage. If one drive in the array fails, the entire array fails.
This level uses mirroring and is useful for redundancy. All of the drives in the array are just a copy of each other with identical information on each one. Its performance is slower than other levels and has less storage capacity, but offers excellent fault tolerance because if one drive fails, you will still have access to your data. It is an easy setup for home users.
This level offers block-level striping with distributed parity. Data is written to all the disks at once and there is a specific parity stripe that allows a rebuild of the array if one disk fails. This level requires a minimum of three drives, with one of the drives being dedicated to storing the parity in the event of a disk failure. It offers fast write times and is best for more advanced users.
This configuration follows the same format as the RAID 5 but adds another disk just for parity. With parity being striped to two drives, the array can now withstand two drive failures, meaning there is greater security for data. Writing performance is much slower with the extra parity operation, and needs an experienced user to rebuild correctly after a disk failure.
This level combines the performance of a RAID 0 with the redundancy of a RAID 1 to offer both speed and fault tolerance. It mirrors all data on a secondary drive but also stripes that data across each set. There is no parity, so a rebuild with a RAID 10 would take much less time compared to a RAID 5 or 6. Unfortunately, storage is cut in half because of the mirrored drives.
Data Recovery for All RAID Levels
A RAID 0,1, and 10 are great levels for beginning or non-technical users such as those who need some data storage at home. RAID 5 and 6 are more popular for small businesses and other corporations with more technical knowledge and dedicated IT departments. Overall, you need a RAID level that makes sense for your data storage needs and that you can easily manage.
No matter what level you choose, there is going to be a chance that your array will fail. When this happens, call Secure Data Recovery. Our engineers have decades of experience working with all RAID levels and have an overall 96% success rate. Call to start your case today at 1-800-388-1266.
See the other posts in our RAID series: