Chapter 11: Drives Flashcards
Write through writes information to the disk before what?
The OS is notified that the write was successful
SAS uses what legacy storage protocol?
SCSI
In NAS technology, what keeps track of where files are located?
The NAS device’s operating system
In the Fibre Channel model what is layer 0?
Physical
The sixth step in a disk array controller operation is?
Head reads servo track and waits for data to rotate underneath the head.
Servo track allows accurate tracking
For a 15,000rpm drive, how long is the rotational latency?
2ms
Linear movement of the head is called?
Seek
The third step in a disk array controller operation is?
Disk array controller executes I/O commands
Platter assembly mounted on a _______ that revolves around an axis
spindle
iSCSI allows SCSI access over what?
TCP/IP
SCSI is limited to how many drives?
14
What feature found in SCSI improves data integrity?
Cyclic redundancy checking
Seek time is the time to get what?
A Track
As a rule of thumb, doubling the number of drives will increase your throughput by how much?
50%
The platters in hard disk drives are coated with what?
Magnetic Material
The second step in a disk array controller operation is?
OS generates an interrupt
The tenth step in a disk array controller operation is?
Controller communicates a completion to the device driver
In NAS technology, what issues disk I/O requests?
The NAS device’s operating system
The time required for the disk to transfer requested data is called what?
Transfer Rate
SAS usually has how many lanes?
4
EIDE cables are typically what length?
18 inches
On a consumer grade disk, the seek operation usually takes how long?
7-10ms
LBA stands for what?
Logical Block Address
iSCSI uses what medium?
Gigabit Ethernet
PATA operates at what voltage?
5v
The ninth step in a disk array controller operation is?
PCI data is transferred into the server main memory