Comptia A+ Identifying purposes and characteristic of a storage devices (WGU)

(computing total sectors in CHS Geometry) cylinders/heads/sector a drive labeled with the maximum allowed CHS eoemtry of 16383/16/63 has how many GB?

7.9 cylinders x heads ________________________ total tracks x sectors ___________________________ total sectors /2/2

designed for modern high-definition video sources. The equipment used to read the resulting discs employs a violet laser, in contrast to the red laser used with standard DVD and CD technologies. Taking a bit of creative license with the color of the laser, the Blu-ray Disc Association named itself and the technology Blu-ray Disc (BD), after this visibly different characteristic. Blu-ray technology further increases the storage capacity of optical media without changing the form factor. On a 12cm disc, similar to those used for CD-ROMs and DVD-ROMs, BD derives a 25GB storage capacity from the basic disc. When you add a second layer to the same or opposite side of the disc, you attain 50GB of storage. The Blu-ray laser is of a shorter wavelength (405nm) than that of DVD (650nm) and CD (780nm) technologies. As a result, and through the use of refined optics, the laser can be focused on a much smaller area of the disc. This leads to a higher density of information being stored in the same area.

BD-ROM

was designed for long-term storage of data .are read-only, meaning that information written at the factory can't be erased or changed. became very popular because they made a great software distribution medium. Programs are always getting larger and increasingly require more room to install, version after version. Instead of installing the program of the day using 100 floppy disks, you could use a single CD-ROM, which can hold approximately 650MB in its original, least-capable format. Although CDs capable of storing 700MB eventually became and continue to be the most common, discs with 800MB and 900MB capacities have been standardized as well.

CD-ROM

attained by placing two media surfaces on the same side of the disc, one on top of the other, and using a more sophisticated mechanism that burns the inner layer without altering the semitransparent outer layer and vice versa, all from the same side of the disc. Add the DL technology to a double-sided disc, and you have a disc capable of holding 17.1GB of information—again twice the capacity of the single-sided version

DVD DL (dual-layer)

These discs have a capacity of 4.7GB, many times the highest CD-ROM capacity. Simple multiplication can sometimes be used to arrive at the capacities of other DVD-ROM varieties. For example, when another media surface is added on the side of the disc where the label is often applied, a double-sided disc is created. Such double-sided discs have a capacity of 9.4GB, exactly twice that of a single-sided disc.

DVD-ROM

the hard disk drive system contains three critical components: This is the translator, converting signals from the controller to signals that the computer can understand. Most motherboards today incorporate the host adapter into the motherboard's circuitry, offering headers for drive-cable connections. Legacy host adapters and certain modern adapters house the hard drive controller circuitry.

Host bus adapter (HBA)

is a standard electronic interface used between a computer motherboard's data paths or bus and the computer's disk storage devices

IDE (integrated drive electronics)

uses the classic 40-pin connector for parallel data communications, whereas SATA uses a more modern 7-pin card-edge connector for serial data transfer.

Pata (Parallel ATA)

a way of combining the storage power of more than one hard disk for a special purpose such as increased performance or fault tolerance. Raid can be implemented into software or in hardware, but hardware raid is more efficient and offers higher performance but at an increased cost.

RAID (redundant Array of Independent Disks)

There are several types of RAID. The following are the most commonly used RAID levels: Also known as disk mirroring. RAID 1 is a method of producing fault tolerance by writing all data simultaneously to two separate drives. If one drive fails, the other contains all of the data, and it will become the primary drive. However, disk mirroring doesn't help access speed, and the cost is double that of a single drive. If a separate host adapter is used for the second drive, the term duplexing is attributed to RAID 1. Only two drives can be used in a RAID 1 array.

RAID 1

There are several types of RAID. The following are the most commonly used RAID levels: Combines the benefits of both RAID 0 and RAID 1, creating a redundant striped volume set. Unlike RAID 1, however, RAID 5 does not employ mirroring for redundancy. Each stripe places data on n -1 disks, and parity computed from the data is placed on the remaining disk. The parity is interleaved across all of the drives in the array so that neighboring stripes have parity on different disks. If one drive fails, the parity information for the stripes that lost data can be used with the remaining data from the working drives to derive what was on the failed drive and to rebuild the set once the drive is replaced.

RAID 5

There are several types of RAID. The following are the most commonly used RAID levels: Also known as disk striping, where a striped set of equal space from at least two drives creates a larger volume. This is in contrast to unequal space on multiple disks being used to create a simple volume set, which is not RAID 0. RAID 0 is not RAID in every sense because it doesn't provide the fault tolerance implied by the redundant component of the name. Data is written across multiple drives, so one drive can be reading or writing while another drive's read-write head is moving. This makes for faster data access. However, if any one of the drives fails, all content is lost. Some form of redundancy or fault tolerance should be used in concert with RAID 0.

Raid 0

a disadvantage of SSD is that :

SSD is still more expensive per byte, and SSDs are not yet available in capacities high enough to rival the upper limits of conventional hard disk drive technology. As of August 2015, for instance, the largest SSD on the market was 2TB, while the largest readily available conventional HDD was 8TB.

computer bus interface that connects host bus adapters to mass storage devices such as hard disk drives, optical drives, and solid-state drives. it succeeded the older parallel ATA standard to become the predominant interface for storage devices.

Serial ATA

a firmware interface designed as a replacement for BIOS

UEFI

A hard drive is constructed in a cleanroom to avoid the introduction of contaminants into the hermetically sealed drive casing. Once the casing is sealed, most manufacturers seal one or more of the screws with a sticker warning that removal of or damage to the seal will result in voiding the drive's warranty. Even some of the smallest contaminants can damage the precision components if allowed inside the hard drive's external shell. The following is a list of the terms used to describe these components in the following paragraphs: Platters Read/write heads Tracks Sectors Cylinders Clusters (allocation units)

anatomy of a hard drive

(anatomy of the hard drive) File systems laid down on the tracks and their sectors routinely group a configurable number of sectors into equal or larger sets called ___________ or _____________ _________. this concept exist because operating system designers have to settle on a finite number of addressable units of storage and a fixed number of bits to address them uniquely.

clusters or allocation units

the hard disk drive system contains three critical components: This component controls the drive. It controls how the drive operates and how the data is encoded Ono the platters. It controls how the data sends signals to the various motors in the drive and receives signals from the sensors inside the drive. most of today's hard disk drive technologies incorporate the controller and drive into one assembly. Today the most common and well-known of these technologies is SATA.

controller

(the basic drive geometry) the number of _____________ is the number of tracks that can be found on any single surface of any single platter. It is called this because the collection of the same number of tracks on all writable surfaces of the hard drive assembly looks like a geometric cylinder when connected together vertically.

cylinders

_________ -________ storage solutions can also benefit from technologies such as intel's SRT but because they are implemented as two separate drives. one conventional HDD and one SSD each with its own separate file system ad drive letter the user can also manually choose the data to move to the SSD for faster read access. Users can choose to implement dual-drive systems with SSDs of the same size as the HDD, resulting in a fuller caching scenario.

dual-drive

MultiMediaCard. An eMMC drive can be permanently embedded on the primary circuit board of a cheaper or smaller mobile device. With its integrated controller logic, the eMMC drive can be made bootable as well. Although fostered beyond the time when development of the removable MMC card ceased, eMMC drives cannot compete outright with SSDs because the former does not have the latter's firmware and fast interfaces, such as SATA. Furthermore, SSDs use multiple flash memory chips as an array, similar to the way RAID uses multiple drives, to attain higher performance than an eMMC drive c

embedded flash memory

a kind of memory that retains data in the absence of power supply.

flash memory

for many years modules and PC Card devices known as ________ _________ offered low to mid capacity storage for devices. The name comes from the concept of easily being able to use electricity to alter the contents of the memory instantly. The original flash memory is still used in devices that require a nonvolatile means of storing critical data and code often used in booting the device, such as routers and switches.

flash memory

the hard disk drive system contains three critical components: This is the physical storage medium. Hard disk drive systems store information on small discs (from under 1 inch to 5 inches in diameter) also called platters, stacked together and placed in an enclosure.

hard disk

______ _____ ______ (___) systems (or hard drives for short) are used for permanent storage and quick access. They reside in the computer where they are semi-permanently mounted with no external access (although there are external and removable hard drives) and can hold more information Han other forms of storage.

hard disk drive (HDD)

this means that you can insert and remove the device with the system powered on. Most USB-attached devices without a file system fall into this category. Non-hot-swappable devices, in contrast, either cannot have the system's power applied when they are inserted or removed or have some sort of additional conditions for their insertion or removal. One subset is occasionally referred to as cold swappable, the other as warm swappable.

hot-swappable devices

a cost-saving alternative to a standard SSD that can still provide a significant increase in performance over conventional HDDs is the ________ ________, can be implemented in two ways: a solid-state hybrid drive and a dual-drive storage solution. Both forms of hybrid drives can take advantage of solutions such as Intel's Smart Response Technology (SRT), which inform the drive system of the most used and highest-value data. The drive can then load a copy of such data into the SSD portion of the hybrid drive for faster read access.

hybrid drives

Flash -based SSDs made with NAND memory use _____ power than HDDs. this made with DRAM can use every bit as much power as conventional drives. The advantage of those made with the standard RAM modules used in desktop motherboards is that the modules can often be upgraded using larger modules, making a larger SSD overall.

less

Hard drives use a ____________ storage medium, and they are known as conventional drives to differentiate them from newer solid-state storage media.

magnetic

the circular disk on which magnetic data is stored in a hard disk drive. it is called this because it is of rigid nature.

platter

and advantage of the SSD is that its able to :

read contents more quickly, can consume less power and produce less heat, and are more reliable and less susceptible to damage from physical shock and heat production than their magnetic counterparts.

The Blu-ray Disc Association duplicated the use of the R suffix to denote a disc capable of being recorded only once by the consumer. Instead of the familiar RW, however, the association settled on RE, short for re-recordable. As a result, watch for discs labeled BD-R and BD-RE. Dual-layer versions of these discs can be found as well. The Blu-ray Disc Association decided against creating separate logos for each BD type, resolving instead to use only the logo shown in Figure 2.9. Discs are labeled most often in a sans-serif font with the actual type of the disc as well as this generic BD logo.

recordable BD formats

CD-recordable (CD-R) and CD-rewritable (CD-RW) drives (also known as CD burners) are essentially CD-ROM drives that allow users to create (or burn) their own CD-ROMs. They look very similar to CD-ROM drives, but they feature a logo on the front panel that represents the drive's CD-R or CD-RW capability. Figure 2.6 shows the CD-R and CD-RW logos that you are likely to see on such drives

recordable CD Formats

discs that could be written to, erased, and rewritten were developed. Drives that contained the firmware to recognize these discs and control the laser varied the laser's power in three levels. The original two levels closely matched those of the writable discs and drives. The third level, somewhere in between, could neutralize the crystalline material without writing new information to the disc. This medium level of power left the disc surface in a state similar to its original, unwritten state. Subsequent high-power laser usage could write new information to the neutralized locations.

recordable discs and burners

A DVD burner is similar to a CD-R or CD-RW drive in how it operates: It can store large amounts of data on a special, writable DVD. Single-sided, dual-layer (DL) discs can be used to write 8.5GB of information to one single-sided disc. Common names for the variations of DVD burning technologies include DVD+R, DVD+RW, DVD-R, DVD-RW, DVD-RAM, DVD-R DL, and DVD+R DL. The "plus" standards come from the DVD+RW Alliance, while the "dash" counterparts are specifications of the DVD Forum. The number of sectors per disc varies between the "plus" and "dash" variants, so older drives might not support both types. The firmware in today's drives knows to check for all possible variations in encoding and capability. The "plus" variants have a better chance of interoperability, even without the disc being finalized.

recordable dvd formats

RAID systems benefit from devices and bays with a single connector that contains both power and data connections instead of two separate connectors. This is known as Single Connector Attachment (SCA). SCA interfaces have ground leads that are longer than the power leads so that they make contact first and lose contact last. SATA power connectors are designed in a similar fashion for the same purpose. This arrangement ensures that no power leads make contact without their singular ground leads, which would often result in damage to the drive. Drives based on SCA are hot swappable. RAID systems that have to be taken offline before drives are changed out, but the system power can remain on, are examples of warm-swappable systems.

single connector attachment (SCA)

have no moving parts, but they use the same solid-state memory technology found in the other forms of flash memory. is limited to a finite number of write (including erase) operations. Algorithms have been developed to spread the write operations over the entire device constantly. Such "wear leveling" increases the life of the SSD, but lack of longevity remains a disadvantage of this technology.

solid-state drives (SSD)

the _______-_______ ________ _________ (____) is a conventional HDD manufactured with a substantial amount of NAND-technologu solid-state storage aboard. The SSHD is known to the operating system as a single drive, and individual access to the separate components is unavailable to the user.

solid-state hybrid drive

(HDD Speeds) To make information available to the electronics more quickly, manufacturers increase the

speed at which the platters spin from one generation of drives to the next, with multiple speeds coexisting in the marketplace for an unpredictable period, at least until the demand dies down for one or more speeds.

________ ________ hold the data being accessed as well as the files that the system needs to operate and the data that needs to be saved.

storage media

an older form of removable storage is the ________ _________. they can be installed internally or externally and use either a digital or analog magnetic tape medium instead of disks for storage. They hold much more data than any other medium but they are also much slower. They are primarily used for batch archival storage, not interactive storage. they are the most reliable over time and were once most common choice in larger enterprises and networks because they were able o hold the most data and were the most reliable over time.

tape backup

The basic hard drive geometry consists of three components:

the number of sectors that each track contains, the number of read/write heads in the disk assembly, and the number of cylinders in the assembly. This set of values is known as CHS (for cylinders/heads/sector)

(anatomy of a hard drive) factory preparation for newer drives or low level formatting in the field for legacy drives. maps the inherent flaws of the platters so that the drive controller know not to place data in these compromised locations. Additionally this phase in drive preparation creates concentric rings, or _______, which are dawn magnetically around the surface of the platters. ______ are then delineated within each of the tracks. These are the magnetic domains that represent the smallest units of storage on the disk's platters. Magnetic drive sectors commonly store only 512 bytes (1/2kb) of data each.

tracks, sectors

incredibly versatile and convenient devices that allow you to store large quantities of information in a very small form factor. Many such devices are merely extensions of the host's USB connector, extending out from the interface but adding little to its width, making them easy to transport, whether in a pocket or laptop bag.

usb flash drives

SSDs are separated into two broad categories:

volatile DRAM-based and Non volatile flash-based.

include USB flash drives and external drives that have a file system. Windows and other operating systems tend to leave files open while accessing them and write cached changes to them at a later time, based on the algorithm in use by the software. Removing such a device without using the Safely Remove Hardware utility can result in data loss. However, after stopping the device with the utility, you can remove it without powering down the system, hence the warm component of the category's name. These are officially hot-swappable devices.

warm-swappable devices