DEA-1TT5 RAID and Data Protection 3

Question 1

What is 'erasure coding' and how does it compare to RAID?

Accepted Answer

It distributes data and redundancy across many nodes using mathematical algorithms, offering more flexible fault tolerance than traditional RAID

Answer

It is another name for RAID 5 parity

Answer

It encrypts data before storing it across multiple disks

Answer

It is a method of compressing data before striping

Question 2

In a RAID 50 configuration, data is striped across multiple RAID 5 sets — what advantage does this provide?

Accepted Answer

It improves performance and fault tolerance by combining striping across multiple redundant parity groups

Answer

It eliminates all parity overhead

Answer

It allows any three drives to fail simultaneously

Answer

It provides a 100% mirror of all data

Question 3

What is the purpose of a 'patrol read' (or disk scrubbing) in a RAID array?

Accepted Answer

To proactively scan all disks for errors and correct them before they cause a drive failure

Answer

To clean dust from disk surfaces using compressed air

Answer

To optimize data placement across RAID stripes

Answer

To verify that the RAID controller firmware is up to date

Question 4

Which RAID level is best suited for a write-intensive database that requires high availability and fast recovery?

Accepted Answer

RAID 10

Answer

RAID 0

Answer

RAID 5

Answer

RAID 6

Question 5

What is an 'URE' (Unrecoverable Read Error) and why is it significant in RAID arrays?

Accepted Answer

A disk read error that cannot be corrected by error correction codes, which can cause data loss during RAID rebuilds

Answer

A controller error that prevents RAID configuration changes

Answer

An encryption error in secure storage environments

Answer

A network error that interrupts iSCSI connectivity

Question 6

In RAID terminology, what is 'stripe size' (or chunk size)?

Accepted Answer

The amount of contiguous data written to a single disk before moving to the next disk in the stripe

Answer

The total capacity of the RAID set

Answer

The number of disks in the RAID group

Answer

The size of the parity block stored on each disk