Which of the following descriptions about the snapshot function of OceanStor Dorado NAS is incorrect?

Question

Options

• AONAS snapshots occupy storage pool space
• BThe shortest period of ONAS snapshot is 15 seconds
• CONAS and SAN snapshots are both ROW snapshots
• DYou can select a snapshot of the NAS at any point in time to roll back

• A
  5% (3)
• B
  2% (1)
• C
  84% (48)
• D
  9% (5)

Explanation

Option C is incorrect because ONAS (NAS) and SAN snapshots use different snapshot technologies: SAN snapshots use ROW (Redirect-on-Write), while ONAS snapshots use COW (Copy-on-Write). In COW, the original data is copied to a snapshot area before being overwritten; in ROW, new writes are redirected to new locations while the original blocks remain untouched for the snapshot.

The distractors are all true statements and therefore not the answer:

• A is correct - ONAS snapshots do consume space in the storage pool, as the COW mechanism must store the original data blocks.
• B is correct - 15 seconds is indeed the minimum configurable interval for ONAS periodic snapshots.
• D is correct - administrators can roll back to any available snapshot point that was previously captured.

Memory tip: Use the phrase "NAS COWs, SAN ROWs" - NAS snapshots Copy-On-Write, SAN snapshots Redirect-On-Write. When you see a statement claiming they are the same type, that's your flag that it's wrong.

No community discussion yet for this question.