DEA-1TT5 RAID and Data Protection 2

Question 1

What happens to a RAID 5 array when a disk fails?

Accepted Answer

The array operates in a degraded mode using parity to reconstruct the missing data on reads

Answer

A RAID 5 array with one failed disk operates in 'degraded mode,' recalculating missing data on-the-fly using parity during reads until a replacement disk is rebuilt.

Question 2

What is 'RAID rebuild' and why can it be risky?

Accepted Answer

Reconstructing a failed disk's data onto a replacement disk, which stresses remaining drives and risks a second failure

Answer

RAID rebuild reconstructs lost data onto a replacement drive by reading all remaining drives intensively, which increases the risk of uncovering another drive's latent errors during the process.

Question 3

Which RAID level mirrors data across two disks, providing full redundancy with 50% usable capacity?

Accepted Answer

RAID 1

Answer

RAID 1 writes identical copies of data to two disks simultaneously, meaning if one disk fails, an exact duplicate exists on the other disk.

Question 4

What is 'copyback' in a RAID context?

Accepted Answer

Migrating rebuilt data from a hot spare back to a new permanent replacement disk

Answer

Copyback is the process of moving data from a hot spare (used during an emergency rebuild) back to a new permanent replacement disk once it has been physically installed.

Question 5

How many minimum disks are required to implement RAID 5?

Accepted Answer

3

Answer

RAID 5 requires a minimum of 3 disks: at least 2 for data striping and 1 disk's worth of distributed parity across all drives.

DEA-1TT5 - Information Storage and Management Exam Practice Test

DEA-1TT5 - Information Storage and Management Exam Practice Test

DEA-1TT5 RAID and Data Protection 2