Virtualization Technologies Questions and Answers

Answer: C

Successive passes copy pages that changed since the last, until a brief final pause transfers the rest. Shared storage or storage migration is required for the disk to be reachable from both hosts. The pause is brief if it converges.

Answer: D

Correct answer: 2 - 4 - 1 - 3

Live migration copies memory while the guest keeps running, so the first pass is followed by iterative passes copying only the pages dirtied during the previous one. When the remaining set is small enough, the guest is paused for a few tens of milliseconds, the remainder and the CPU state are transferred, and it resumes on the target. The iteration exists precisely to make that final pause short enough to go unnoticed.

Answer: A

Correct answer: Both A and R are true, and R is the correct explanation of A

Both are true and the reason is the mechanism. Each iterative pass must transfer the pages dirtied during the previous one, so convergence requires the dirty rate to fall below the transfer rate. A guest writing memory faster than the link can carry never converges, and the migration either stalls indefinitely or must be forced with a long pause. Throttling the guest’s CPU is the usual remedy.

Answer: B

Hardware is still required and someone still runs it. The other three are the three capabilities that made virtualisation transform data centre operations. Hardware is still needed. Someone must run the machines beneath.

Answer: C

It allows a rollback to a known state, which is invaluable during upgrades. Long lived snapshots grow and degrade performance, so they are not a substitute for backup. Rollback is its purpose. Upgrades are the usual occasion for one.

Answer: D

Both are true and the reason gives both objections, and losing the underlying storage loses the snapshot along with the machine it was meant to protect. Growth is the other objection. Dependence on the same storage is fatal.

Answer: A

Correct answer: 1 and 2 only

Statements 1 and 2 are correct: a snapshot allows rollback, and a long-lived one degrades performance because every write must be redirected into a growing delta file that is also read on every access. Statement 3 is a dangerous belief - a snapshot depends on the original disk and lives on the same storage, so it protects against a bad upgrade and against nothing else. It is not a backup.

Answer: B

Thin provisioning, snapshots and migration between arrays all follow from that decoupling. The guest sees a volume without knowing what lies beneath it. Decoupling is what enables the rest. Migration between arrays follows from it.

Answer: C

Correct answer: as it is written rather than at creation

A thin-provisioned volume consumes physical capacity only as blocks are actually written, so a terabyte volume holding ten gigabytes occupies ten. It raises utilisation substantially, since most volumes are sized for growth that never arrives, and it moves the capacity risk from provisioning time to run time.

Answer: D

Correct answer: Both A and R are true, and R is the correct explanation of A

Both are true and the reason is why the monitoring is necessary. Because allocation follows writing, the provisioned total may far exceed the physical pool - which is fine until the pool fills. At that point writes fail across every volume drawing on it, not just the one that grew, so the pool must be watched and expanded ahead of demand rather than in response to it.