List I List II A. RAID Level 2 I. Block interleaved distribution parity B. RAID Level 3 II. Also known as P+Q redundancy Scheme C. RAID Level 5 III. Bit interleaved parity D. RAID Level 6 IV. Also known as Memory style error correcting code organization
Choose the correct answer from the options given below:
A→IV, B→III, C→I, D→II
RAID Level Matching Explained
This question requires matching different Redundant Array of Independent Disks (RAID) levels with their corresponding characteristics described in List II.
Understanding RAID Levels and Characteristics
Let's break down each RAID level mentioned and its features:
- RAID Level 2: This level is characterized by its use of Error Correcting Codes (ECC), specifically Hamming codes, distributed across multiple drives. It operates at the bit level and is often associated with a "memory style" organization because of the ECC, which requires dedicated drives for parity bits.
- RAID Level 3: This RAID level uses dedicated parity, meaning one drive is solely for parity information. It employs bit interleaving, where data bits are striped across multiple drives, and a single parity bit is calculated for each corresponding bit position. It's efficient for large files but less so for small, random ones.
- RAID Level 5: This is a widely used level that offers a good balance between storage efficiency, performance, and fault tolerance. It uses block interleaved distribution parity. Data is striped in blocks across multiple drives, and parity information is also distributed across all drives, rather than being dedicated to a single drive.
- RAID Level 6: This level enhances fault tolerance beyond RAID 5 by implementing dual distributed parity. It can withstand the failure of two drives simultaneously. The characteristic described as "P+Q redundancy Scheme" refers to these two independent parity calculations used in RAID 6.
Matching the Lists
Based on the descriptions above, we can perform the matching:
- A. RAID Level 2 matches with IV. Also known as Memory style error correcting code organization (due to its use of ECC).
- B. RAID Level 3 matches with III. Bit interleaved parity (its method of data distribution and parity calculation).
- C. RAID Level 5 matches with I. Block interleaved distribution parity (its block-level striping and distributed parity).
- D. RAID Level 6 matches with II. Also known as P+Q redundancy Scheme (its use of dual parity).
Correct Matching Summary
The correct matching is therefore:
- A → IV
- B → III
- C → I
- D → II
This corresponds to the option A→IV, B→III, C→I, D→II.
Important Questions from Disk Scheduling
Which of the following is the time taken to move an access arm to a certain track on a disk?
Move the Read/Write head of disk in or out to position on a correct track is known as ______.
_______ is a process of lifting the process from memory and placing it on disk.
- What shall be the total head movement of cylinders if the FCFS disc scheduling method is used ?
- What will be the total head movement of cylinders for the SSTF disc Scheduling technique ?
