Chapter 3

1:	What are the two main performance areas in storage networks?
A1:	Answer: Bandwidth and latency
2:	True or false: DAS storage is less reliable than network storage.
A2:	Answer: False. DAShas historically been extremely reliable.
3:	Which of the following is not part of the software used in the I/O path: file system, volume manager, storage resource manager, multipathing drivers, or SCSI driver?
A3:	Answer: Storage resource manager
4:	What are the two layers most HBAs need?
A4:	Answer: SCSIapplication layer driver and network driver
5:	Name the host system hardware components in the I/O path.
A5:	Answer: System processors, system memory, memory bus, I/O bus, and host bus adapter
6:	What is flow control used for?
A6:	Answer: It adjusts the data rate of data being transmitted by a network node.
7:	Name the subsystem hardware elements found in the I/O path.
A7:	Answer: Network port, storage controller, cache memory, storage interconnect, storage device, and storage media
8:	True or false: Storage controllers in subsystems are the same as host system HBAs.
A8:	Answer: False. They have different logic to handle different types of tasks.
9:	True or false: File systems and operating systems do not have to be from the same vendor.
A9:	Answer: True. Installable file systems have worked very successfully for many years.
10:	True or false: The volume manager usually writes I/Os directly to disk device drivers.
A10:	Answer: False. The operating system kernel does this.