| 1: | What is the primary function of storage virtualization? |
| A1: | Answer: To create upstream storage address spaces from downstream storage address spaces |
| 2: | What is the similarity between a SAN virtualization system and a storage subsystem? |
| A2: | Answer: A SANvirtualization system is similar to placing the subsystem controller in the SANinstead of in a subsystem cabinet. |
| 3: | How do volume managers and SAN virtualization systems differ in their "view" of the network? |
| A3: | Answer: SANvirtualization systems work with multiple hosts, and volume managers work with a single host. |
| 4: | Describe the difference between concatenation and striping. |
| A4: | Answer: Concatenation appends a storage address space to another, and striping intertwines strips of different address spaces. |
| 5: | What is the difference between fan-in and fan-out of a SAN virtualization system? |
| A5: | Answer: Fan-in is the number of simultaneous initiator/target connections available through a single port. Fan-out is the number of downstream LUNs used to form a single upstream LUN. |
| 6: | How can high utilization of storage lead to poorer I/O performance? |
| A6: | Answer: It causes disk fragmentation, which leads to longer seek times and the creation of hot spots on disk drives. |
| 7: | True or false: Storage subsystems have more predictable connection environments than volume managers or SAN virtualization controllers. |
| A7: | Answer: True |
| 8: | Starting with the filing system and looking downstream, name the elements of the I/O software stack in a host system. |
| A8: | Answer: Filing system, volume manager, multipathing software, SCSIcommand driver |
| 9: | If a SAN virtualization system is a single point of failure, what can be done to improve availability? |
| A9: | Answer: Operate two or more virtualization systems in a cluster configuration. |