| 1: | What is primary storage, and where is it located? |
| A1: | Answer: Primary storage is online disk storage used by applications and systems. It is local to applications systems. |
| 2: | What is secondary storage, and where is it located? |
| A2: | Answer: Secondary storage is used by remote copy systems to hold redundant copies of data. It can be located at the primary site or at remote secondary sites. |
| 3: | What are the three primary objectives of remote copy systems? |
| A3: | Answer: Provide ready access to data at remote storage sites Maintain data consistency Resume normal operations at the primary processing site |
| 4: | How can remote copy slow down application processing? |
| A4: | Answer: Responses from write commands can be delayed, causing an I/O bottleneck. |
| 5: | What is the latency of signal propagation in a fiber-optic cable? |
| A5: | Answer: 5 microseconds per kilometer or 8 microseconds per mile |
| 6: | How many signals have to be transmitted for each write operation in remote copy? |
| A6: | Answer: Four |
| 7: | What is the difference between synchronous and asynchronous mode? |
| A7: | Answer: Synchronous mode acknowledges each write before forwarding another. Asynchronous mode allows multiple writes to be forwarded without receiving an acknowledgment from the remote site. |
| 8: | True or false: The receiving controller never acts like a SCSI initiator. |
| A8: | Answer: False. It acts like an initiator when writing to secondary storage. |
| 9: | Name three locations where secondary storage can be found. |
| A9: | Answer: Local site or campus, bunker site, and remote site |