Disk Mirroring (RAID 1)

RAID 1 stands for Redundant Array of Independent Disks 1. RAID 1, also known as disk mirroring, is the technique of storing a copy of the same data in another disk. Here, the data is not broken into blocks rather a duplicate copy of the data is stored in another disk. A minimum of 2 disks are required in RAID.

Supposing, we have some data namely, D1, D2, and D3. In RAID 1, along with these original data we store copies of these data in another disk. Below is a diagram justifying the above statement and thus explaining the concept of RAID 1.

RAID 1

Mirroring of RAID 1

Basically, the RAID 1 Mirroring is implemented when some fault tolerance is desired. The ability of the required data in the array to survive the failure of a disc is mainly known as fault tolerance. Like every piece of data in a mirrored array is duplicated over two or more hard discs accordingly. That’s why, all of one’s crucial data would be kept on a mirrored array to access the required data from the other drive, even in the event that one of the hard drives may fail. The RAID 1 mirroring is available across all of ZNetLive’s dedicated servers as well.

Applications Recommended for RAID 1

• Various types of transactional applications like Financial, Accounting, Payroll, etc.
• Emails communications
• Operating Systems

Advantages of RAID 1

• RAID 1 provides applications with increased data security. In case, one of the disks fails, the other disk contains a duplicate copy of the same data. Thus, RAID 1 provides a good fault tolerance.
• Data redundancy is provided in RAID 1.
• RAID 1 provides good performance for the read operation.

Disadvantages of RAID 1

• In RAID 1 , the write operation is slower as compared to the read operation.
• Here, there is a wastage of storage space as we keep the same data in two different disks.
• The cost incurred in RAID 1 is high.

Therefore, RAID 1 can be used mostly in cases where fault tolerance, data redundancy and high availability is required by the applications.

Frequently Asked Questions

Q.1: What is disk mirroring?

Answer: 

Disk mirroring refers to the technique of storing duplicate copy of the same data in another disk. This technique helps in providing effective fault tolerance thereby enhancing the security of data.

Q.2: What is RAID?

Answer: 

RAID stands for Redundant Array of Independent Disks. RAID is a technique in which a combination of multiple disks are used for achieving increased performance and data redundancy.

Q.3: What is the major advantage of RAID 1?

Answer: 

RAID 1 provides effective fault tolerance thereby increasing the security of data.

Q.4: Give some common applications of RAID 1?

Answer: 

RAID 1 finds its applications in emails and several transaction applications like financial systems. It is ideal for use in mission-critical systems like accounting systems.