RAID: Redundant Array of Independent Disks

What does RAID stand for?

• Redundant Array of Independent Disks

• Random Access Integrated Data

• Rapid Array of Integrated Devices

• Reliable Access of Independent Drives

Answer explanation

RAID stands for Redundant Array of Independent Disks, which is a technology that combines multiple disk drives into a single unit for data redundancy and performance improvement.

Why is RAID used? (Select all that apply)

• Improved Performance

• Fault Tolerance

• Increased Storage Capacity

• Reduced Cost

Answer explanation

RAID is used for Improved Performance by distributing data across multiple disks, Fault Tolerance by mirroring or parity, and Increased Storage Capacity by combining drives. Reduced Cost is not a primary benefit.

Which RAID type is described as having no fault tolerance and losing all data if one drive fails?

• RAID 0

• RAID 1

• RAID 5

• RAID 6

Answer explanation

RAID 0 offers no fault tolerance, meaning if one drive fails, all data is lost. Unlike RAID 1, RAID 5, and RAID 6, which provide redundancy, RAID 0 focuses on performance without any data protection.

Which RAID type is ideal for systems requiring high data reliability, such as databases or financial records?

• RAID 0

• RAID 1

• RAID 5

• RAID 6

Answer explanation

RAID 1 is ideal for high data reliability as it mirrors data across two drives, ensuring that if one drive fails, the data remains intact on the other. This is crucial for databases and financial records where data integrity is paramount.

What is a drawback of RAID 6?

• Increased write latency due to dual parity calculations

• Limited storage capacity compared to RAID 0

• No data redundancy

• Inability to recover from a single disk failure

Answer explanation

RAID 6 provides dual parity for data protection, which results in increased write latency due to the need for additional calculations. This is a significant drawback compared to other RAID levels.

What is RAID 10 and what are its use cases and drawbacks?

• RAID 10 is a combination of RAID 1 and RAID 0, used for high performance and redundancy, but it requires a minimum of four disks and has a high cost.

• RAID 10 is a type of RAID that provides only redundancy without performance benefits.

• RAID 10 is a software-based RAID solution that is used for data backup.

• RAID 10 is a cloud-based storage solution that offers unlimited storage capacity.

Answer explanation

RAID 10 combines RAID 1's redundancy with RAID 0's performance, making it ideal for applications needing both. It requires at least four disks and can be costly, which are important considerations for its use.

What is a common problem caused by RAID related to drive failure, and what is the solution?

• Data loss; replace the failed drive and rebuild the array.

• Increased speed; add more drives to the array.

• Higher costs; switch to a cheaper RAID level.

• Reduced storage capacity; upgrade to larger drives.

Answer explanation

RAID can lead to data loss if a drive fails. The correct solution is to replace the failed drive and rebuild the array, ensuring data integrity and availability.

How can rebuild time be a problem in RAID, and what is the suggested solution?

• Rebuild time can lead to data loss; the solution is to use faster drives.

• Rebuild time can cause system downtime; the solution is to use RAID 0.

• Rebuild time can degrade performance; the solution is to use RAID 6.

• Rebuild time can increase failure risk; the solution is to use hot spares.

Answer explanation

Rebuild time can increase the risk of failure because the system is vulnerable while rebuilding. Using hot spares allows for immediate replacement of a failed drive, minimizing the risk during the rebuild process.

What is the issue with RAID controller failure, and how can it be addressed?

• RAID controller failure can lead to data loss and system downtime; it can be addressed by replacing the controller and restoring data from backups.

• RAID controller failure has no impact on data integrity; it can be ignored.

• RAID controller failure only affects the speed of data access; it can be addressed by upgrading the controller.

• RAID controller failure is a rare occurrence and does not require any specific action.

Answer explanation

RAID controller failure can cause significant issues like data loss and downtime. The correct approach is to replace the faulty controller and restore data from backups to ensure system integrity and availability.

How does RAID handle data corruption, and what is the recommended solution?

• RAID uses parity to detect and correct errors, and the recommended solution is to replace the faulty drive.

• RAID does not handle data corruption, and the recommended solution is to use backups.

• RAID uses checksums to detect errors, and the recommended solution is to restore from a backup.

• RAID automatically repairs corrupted data, and the recommended solution is to do nothing.

Answer explanation

RAID employs parity to detect and correct errors, ensuring data integrity. When a drive fails, the recommended action is to replace the faulty drive to maintain the RAID's functionality and protect against data loss.