DEA-1TT5 Replication Technologies 1 — Questions and Answers
Question 1: What is the primary purpose of storage replication in an enterprise environment?
- To increase storage capacity at the primary site
- To create copies of data on separate storage systems for availability and disaster recovery (Correct answer)
- To improve read performance by distributing data across arrays
- To reduce storage costs through deduplication
Correct answer: To create copies of data on separate storage systems for availability and disaster recovery
Storage replication creates duplicate copies of data on geographically or logically separate systems to ensure availability and enable disaster recovery.
Question 2: Which type of replication requires the write operation to be confirmed on BOTH source and target before acknowledging success to the host?
- Asynchronous replication
- Delta replication
- Synchronous replication (Correct answer)
- Cascade replication
Correct answer: Synchronous replication
Synchronous replication waits for the remote target to acknowledge the write before returning success to the host, ensuring zero data loss between sites.
Question 3: What does Recovery Point Objective (RPO) measure in the context of replication?
- The maximum time allowed to restore a system after a failure
- The maximum acceptable amount of data loss measured in time (Correct answer)
- The geographic distance allowed between source and target sites
- The bandwidth required to sustain replication traffic
Correct answer: The maximum acceptable amount of data loss measured in time
RPO defines the maximum tolerable period of data loss, measured in time, that a business can accept after a disaster or disruption.
Question 4: In asynchronous replication, when is the write operation acknowledged to the host?
- Only after the remote target confirms receipt of the data
- After the data is written locally, before propagation to the remote site (Correct answer)
- Simultaneously as data is written to both source and target
- Only during scheduled batch replication windows
Correct answer: After the data is written locally, before propagation to the remote site
Asynchronous replication acknowledges the write locally first, then propagates data to the remote site independently, reducing latency impact on the host application.
Question 5: Which replication topology involves a single source replicating to multiple separate target sites?
- Cascade replication
- Fan-in replication
- Fan-out replication (Correct answer)
- Bi-directional replication
Correct answer: Fan-out replication
Fan-out replication sends data from one source to multiple targets simultaneously, useful for distributing copies to several disaster recovery or test environments.
Question 6: What is a replication 'journal' used for in continuous data protection (CDP)?
- A log file that records all failed replication attempts for troubleshooting
- A chronological record of write operations that enables point-in-time recovery (Correct answer)
- A database catalog of all replicated volumes and their current status
- A scheduled performance report for the replication infrastructure
Correct answer: A chronological record of write operations that enables point-in-time recovery
A journal captures a continuous, time-stamped sequence of write operations, allowing recovery to any specific point in time within the journal retention window.
Question 7: What is the main performance disadvantage of synchronous replication compared to asynchronous replication?
- Higher storage capacity requirements at the target site
- Inability to replicate across more than two sites simultaneously
- Write latency increases because the host waits for remote acknowledgment on every write (Correct answer)
- Requirement for identical storage hardware models at both sites
Correct answer: Write latency increases because the host waits for remote acknowledgment on every write
Synchronous replication adds round-trip network latency to every write I/O because the host cannot proceed until the remote site confirms the write, degrading application performance.
DEA-1TT5 Replication Technologies 1
What is the primary purpose of storage replication in an enterprise environment?