DEA-1TT5 Replication Technologies 2 — Questions and Answers
Question 1: Which replication mode acknowledges a write after the data is written to a local persistent buffer but before the remote site confirms receipt?
- Asynchronous replication
- Synchronous replication
- Semi-synchronous replication (Correct answer)
- Snapshot-based replication
Correct answer: Semi-synchronous replication
Semi-synchronous replication writes to a local persistent buffer and acknowledges the host, then propagates to the remote site, balancing near-zero RPO with reduced latency impact.
Question 2: What does 'delta replication' refer to in storage systems?
- Replicating a full copy of all data every day during a maintenance window
- Replicating only the changed blocks or files since the last replication cycle (Correct answer)
- Replicating data to a geographically distant tertiary location
- Replicating metadata and directory structures without the actual data blocks
Correct answer: Replicating only the changed blocks or files since the last replication cycle
Delta replication transfers only the data that has changed since the previous replication pass, significantly reducing bandwidth consumption and replication time.
Question 3: In a fan-in replication topology, multiple source systems send their data to:
- Multiple independent target systems, one per source
- A single consolidated target system (Correct answer)
- A cascade chain of secondary and tertiary systems
- Bi-directional peer systems that also act as sources
Correct answer: A single consolidated target system
Fan-in replication aggregates data from several source systems into a single target, commonly used for centralized backup or consolidation scenarios.
Question 4: What is the purpose of a 'replication consistency group'?
- A set of volumes replicated together to maintain write-order consistency across all members (Correct answer)
- A group of storage arrays that share a common replication license
- A collection of replication policies that share the same RPO target
- A cluster of target systems that collectively store replicated data
Correct answer: A set of volumes replicated together to maintain write-order consistency across all members
A consistency group ensures that a set of related volumes (such as those belonging to one application) are replicated in a coordinated, crash-consistent manner.
Question 5: Which replication mode is best suited for long-distance replication where network latency is a significant factor?
- Synchronous replication
- Asynchronous replication (Correct answer)
- Semi-synchronous replication
- Write-through replication
Correct answer: Asynchronous replication
Asynchronous replication decouples the host write acknowledgment from remote delivery, making it tolerant of high-latency WAN links over long distances.
Question 6: What is 'cascade replication' in a multi-site storage architecture?
- Data is replicated from Site A to Site B, and then from Site B onward to Site C (Correct answer)
- Multiple sources simultaneously replicate to a single consolidated target
- Replication that triggers automatically only when storage utilization exceeds a threshold
- Replication that uses multiple parallel network paths for load balancing
Correct answer: Data is replicated from Site A to Site B, and then from Site B onward to Site C
In cascade replication, Site A replicates to Site B, which in turn replicates to Site C, creating a chain useful for multi-tier disaster recovery architectures.
Question 7: What is a 'replication session' in storage system terminology?
- A scheduled maintenance window during which replication is allowed to run
- A logical connection established between source and target volumes for ongoing data replication (Correct answer)
- A periodic report summarizing replication performance and error statistics
- A group of storage administrators assigned to manage the replication infrastructure
Correct answer: A logical connection established between source and target volumes for ongoing data replication
A replication session is the active logical relationship between a source volume and its target, governing how data transfers occur between the two endpoints.
DEA-1TT5 Replication Technologies 2
Which replication mode acknowledges a write after the data is written to a local persistent buffer but before the remote site confirms receipt?