Chapter 6: Storage Flashcards
Hard Disk Drives (HDDs)
Most common of magnetic media; Nonvolatile
Solid State Drives (SDD)
Used to store operating systems and files, similar to a magnetic hard disk drive; Write data to nonvolatile microchips or to DRAM
Capacity
Accessible capacity varies depending on the environment the hard drive is used in
Data Throughput
The actual data transfer rate, usually less than the maximum
Cache (Buffer)
Cache on most hard drives is on-board DRAM
Rotational Speed (Magnetic disks only)
Platters in the example hard drive can rotate a maximum of 7,200 RPM; Other typical speeds are 5,400 RPM and 10,000 RPM
Latency (Magnetic disks only)
Delay in time before a particular sector on the platter can be read
Defragment (Defragging)
Rearranges the data on a partition or volume so that it is laid out in a contiguous, orderly fashion
Hot-swappable
Drives that can be removed and replaced while the device is on
Fault tolerance
The capability of the hard drive system to continue working after there is a problem with one of the drives
RAID 1
Striping; Not fault tolerant; 2 minimum number of disks
RAID 1
Mirroring; Fault tolerant; Only 2 disks
RAID 5
Striping with Parity; Fault tolerant; 3 minimum number of disks
RAID 10
Combines the advantages of RAID 1 and RAID 0; Fault tolerant; 2 minimum number of disks
Calculate the maximum read speed of a CD-ROM drive 48x
48 x 150 KB = 7.2 MB/s
CD-R
Compact Disc-Recordable; 48x (7.2 MB/s) or 52x (7.8 MB/s)
CD-RW
Compact Disc-ReWritable; 24x (3.6 MB/s) or 32x (4.8 MB/s)
Capacity of DVD-5
4.7 GB
Capacity of DVD-18
17 GB
Calculate the maximum read speed of a DVD drive 16x
16 x 1.32 MB/s = 21 MB/s
Blu-ray Disc Recordable (BD-R)
Writes to a Blu-ray disc once
Blue-ray Disc Recordable Erasable (BD-RE)
Can be erased and re-recorded multiple times
NAND Flash Memory
A type of non-volatile storage technology that does not require power to retain data.
Bad Block Management
Maintains a table of the faulty blocks within the USB flash device, making sure not to save data to those blocks; Blocks divided into pages, between 512 bytes and 4 KB; Each page has error detection and correction information