RAID Configuration Explained

Key Concepts

• RAID 0
• RAID 1
• RAID 5
• RAID 6
• RAID 10

RAID 0

RAID 0, also known as striping, distributes data evenly across two or more disks. This configuration increases performance by allowing multiple disks to read and write data simultaneously. However, RAID 0 offers no redundancy, meaning if one disk fails, all data is lost.

Example: Imagine you have two bookshelves. RAID 0 would split your library into two halves, placing half the books on each shelf. While this makes finding books faster, if one shelf collapses, you lose half your library.

RAID 1

RAID 1, or mirroring, involves creating an exact copy of data on two or more disks. This configuration provides redundancy, ensuring that if one disk fails, the data is still accessible on the other disk(s). However, it does not improve performance significantly.

Example: Think of RAID 1 as having two identical bookshelves. Each shelf contains the exact same books. If one shelf collapses, you still have a complete set of books on the other shelf.

RAID 5

RAID 5 combines striping with parity data distributed across three or more disks. Parity data is used to reconstruct data if a disk fails. This configuration offers a balance between performance and redundancy, as it allows for the failure of one disk without data loss.

Example: Consider three bookshelves. RAID 5 would split your library into three parts, with each part containing a mix of books and parity information. If one shelf collapses, you can reconstruct the missing books using the parity information on the other shelves.

RAID 6

RAID 6 is similar to RAID 5 but uses two sets of parity data distributed across four or more disks. This configuration allows for the failure of up to two disks without data loss, providing higher redundancy than RAID 5.

Example: Imagine four bookshelves. RAID 6 would split your library into four parts, with each part containing a mix of books and two sets of parity information. If two shelves collapse, you can still reconstruct the missing books using the parity information on the remaining shelves.

RAID 10

RAID 10, or RAID 1+0, combines RAID 1 (mirroring) and RAID 0 (striping). It requires a minimum of four disks, with data mirrored across pairs and then striped across the mirrored pairs. This configuration offers high performance and redundancy, as it allows for the failure of one disk per mirrored pair without data loss.

Example: Picture four bookshelves arranged in two pairs. Each pair contains identical books (mirroring), and the pairs are split into two parts (striping). If one shelf in a pair collapses, you still have the complete set of books on the other shelf in that pair, and the other pair remains intact.