2024-11-23

Data Storage

Data storage knowledges, online data storage, data storage skills and more!

The ever-changing storage system technology

DATARECOVERYUNION.COM04 mins

Today’s storage technology encompasses all sorts of storage media. These could include WORM systems, tape library systems and virtual tape library systems. Over the past few years, NAS and SAN systems have provided excellent reliability. What is the difference between the two?

• NAS (Network Attached Storage) units are self-contained units that have their own operating system, file system, and manage their attached hard drives. These units come in all sorts of different sizes to fit most needs and operate as file servers.

• SAN (Storage Area Network) units can be massive cabinets – some with 240 hard drives in them! These large 50+ Terabyte storage systems are doing more than just powering up hundreds of drives. These systems are incredibly powerful data warehouses that have versatile software utilities behind them to manage multiple arrays, various storage architecture configurations, and provide constant system monitoring.

For some time, large-scale storage has been out reach of the small business. Serial ATA (SATA) hard disk drive-based SAN systems are becoming a cost-effective way of providing large amounts of storage space. These array units are also becoming main stream for virtual tape backup systems – literally RAID arrays that are presented as tape machines; thereby removing the tape media element completely.

Other storage technologies such as iSCSI, DAS (Direct Attached Storage), Near-Line Storage (data that is attached to removable media), and CAS (Content Attached Storage) are all methods for providing data availability. Storage architects know that just having a ‘backup’ is not enough. In today’s high information environments, a normal nightly incremental or weekly full backup is obsolete in hours or even minutes after creation. In large data warehouse environments, backing up data that constantly changes is not even an option. The only method for those massive systems is to have storage system mirrors – literally identical servers with the exact same storage space.

How does one decide which system is best? Careful analysis of the operation environment is required. Most would say that having no failures at all is the best environment – that is true for users and administrators alike! The harsh truth is that data disasters happen every day despite the implementation of risk mitigation policies and plans.

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CD Optical Storage Glossary of Computer Terms (Letter W)

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Warp
A special effect sequence of morph images that simulate smooth transitions of dissimilar frames.

WYSBYGI
“What You See Before You Get it.” An extension of WYSIWYG interface design allowing the user to view and edit selected smaller areas from a preview dialog box prior to committing special effects with the processing load of only a portion of the entire file.

WYSIWYG
“What You See Is What You Get.” A working interface of many authoring systems where an author sees the screens as he develops them exactly as they will appear to the user.

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CD Optical Storage Glossary of Computer Terms (Letter U)

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UART
Universal Asynchronous Receiver-Transmitter. An electronic circuit contained within the communications port(s) of the computer that decodes and encodes data in the fashion required by the specific machine for receiving and transmitting purposes. The UART also performs the actual data transmission to the communication device, once it has been encoded and is ready to send.

UPS
Uninterruptible Power Supply. A battery reserve system for computer power installed to supply power in the event of outage. These systems protect against data loss during power outage.

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New SMART technology in HP Hard Disk Drive

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HP Hard Disk DriveDuring the past years, the new, advanced technology of SMART has been introduced in the hard disk drives. The SMART stands for “Self Monitoring Analysis and Reporting Technology”. There are many benefits of the SMART technology. With the help of the SMART technology, the user is given a warning about the hard disk drive incase of imminent failure. In this way the user can change the hard disk drive before its failure.

The HP also has introduced the “SMART technology” in their hard disk drives. The SMART technology checks the key parameters of the hp hard disc drive, and gives message to the user in case if there is any problem in the hard disk drive. The performance of the hard disk drive is not affected during the monitoring process of the SMART technology. In case if any type of error is detected by the “SMART technology”, then an immediate message displays on the screen of the user.

The SMART technology has three versions “SMART”, “SMART-II” and “SMART-III”. In the year 1995, the SMART was developed by Compaq. During the drive activity of the hard disk drive, the SMART monitors and keeps eye on the major attributes and the key parameters of the hard disk drive. The “Client Management” or the Basic input output system (BIOS) gives warning message to the user incase the key parameters cross the limits that are defined.

The SMART-II makes the SMART technology more reliable. With the help of SMART-II, the SMART technology uses the offline data. So, the SMART technology can determine the health of the hard disk drive during the time when the hard drive is inactive. Both the SMART-1 and SMART-2 are supported by the SMART-III. By using the SMART-III, the SMART technology completes the “media self scan”. The latest feature has been added to the SMART-III that enforces the coverage. This enforcement is made even when the drive’s usage cycle is under heavy duty.
The SMART performs the job well of detecting the errors and identifying the errors to the user that affect the performance of the hard disk drive. The HP hard disk drives have the technology that helps the smooth flow of the data between the “Host interface” and the “Media”. Therefore, the HP Hewlett-Packard hard drives are more reliable and robust. In every block of 512bytes that are in “data-path” of the “cache Random Access Memory” of HP hard disk drive is added a parity-code. This is done to make sure that the data between the host and the media is moved swiftly.

When the disc is being read, after the transfer of data from the disc it generates a parity-code of two byte. The parity-data is again monitored when it is moved to interface of the hard drive from data-buffer. When the data is written onto the hard disk, the SMART 4 generates a parity-code of two bytes. Before the data moves into the buffer, this parity-code of two bytes attached to the data. Before the writing and transfer of the data to the data buffer, the SMART-4 checks the parity-code. A protocol of the HP hard disk notifies the Operating System of the host if an error occurs during the movement of the data. It is up to the operating system of the host to take action either by resending the command or to send message to the user about the error in the data. The Hewlett-Packard Binary input output system (BIOS) can also send the failure message when the system is rebooted next time. There is no need to install any additional softwares because the BIOS of the HP can handle the status commands of the SMART technology.

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CD Optical Storage Glossary of Computer Terms (Letter T)

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Tablet
A pressure sensitive input device used in conjunction with a pen to edit digital images.

Touch-screen
A display monitor that is pressure sensitive to touch and is often used as a multimedia control instead or in conjunction with a keyboard. Better authoring systems should have touch-screen interface functions built in their software. Touch-screen displays vary widely and can be accomplished with special overlays or can come as integral screens with built-in touch-screen capabilities. The best screens also feature z-axis control, which allows screen response at different rates depending on the level of pressure applied.

Track
A sequence of contiguous data, the beginning, length, mode and end of which are defined in the table of contents, which is held in the Q subcode channel of the lead-in area of the disc. The two types of tracks currently defined are the CD-DA track according to the CD-ROM specification that is also used in CD-I. In CD-DA the length of a track is related to playing times between four seconds and 72 minutes.

Tuning
The Group term for a number of image editing activities including color and grey balancing, hue & saturation, gamma, histogram, and contrast adjusting…etc.

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CD Optical Storage Glossary of Computer Terms (Letter S)

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Scanning
The most common practice of encoding real images into digital form Accomplished by use of a scanner which passes an image sensor across the original

Screen grabs
Common term for the capturing screen rasterization images and video stills to digital files. Can be preformed with software or hardware, but quality may vary between method used.

SCSI
Small Computer System Interface. The abbreviation is pronounced “scuzzy.” A connection that allows high-speed information transfer between the computer and any external devices at speeds in the range of 4 to 5 megabytes per second. This specification also allows multiple devices to be connected via addresses to a single port (receptacle).

SCSI-II
A specification developed to provide greater speed and performance. An SCSI-II connection provides transfer rates ranging from 10 to 40 megabytes per second.

Selection
The term for indicating the desired area to be effected by editing.

Sharpen
To increase contrast along object edges to improve image appearance.

SIMM
Single In-line Memory Module. A small narrow circuit board containing Random Access Memory Chips (the electronic devices that store data while your computer works with it). SIMMs plug into special slots inside the computer to give the computer extra memory.

Special effects
Digital image manipulation techniques for enhancing quality or creating unusual appearances. Can also be used to remove undesirable image attributes.

Spray
To paint with a diffused edge to simulate “air-brush” feathering

Storyboard
A method of planning the content of a presentation by drawing sketches of each screen with notes about what happens in that scene.

Substitution
the process of replacing colors in a image with colors or patterns on the pallet for the image. this is implemented during color format conversion and pallet correction

SyQuest
A manufacturer of SCSI removable cartridge hard drives. This drive specification has been widely used in pre-press and publishing situations.

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CD Optical Storage Glossary of Computer Terms (Letter R)

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Resampling
The practice of interpolating an image of one specification and producing an image of another specification from that interpolation.

Resolution
Defines image quality of a display. It refers to the number of pixels available on a display. Resolution controls the level of detail that can be presented on a screen.

Retouch
Digital image editing processes used to restore damaged photographs for reproduction

RLE
Run-Length Encoding: a data compression technique that records repeated data elements with the same value, which is coded once along with a count of the number of times it occurs.

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CD Optical Storage Glossary of Computer Terms (Letter P)

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Paint
to apply color or gradient to an area of an image

Palette
A group of selected colors used by a graphics board. The EGA board uses a palette of 16 colors. VGA boards in some resolutions provide a palette of 256 colors.

PCI Local Bus
The Peripheral Component Interconnect (PCI) local bus

PCMCIA
Personal Computer Memory Card International Association. PCMCIA is becoming the link between desktop and notebook computing for data transfer and storage. PCMCIA slots perform the same functions as expansion slots on PC compatibles.

Photo CD
Generic term used to refer to Digital images on compact disc (see Kodak Photo CD)

Pixel
Picture Element. The smallest element of a screen represented as a point of specific color and intensity level.

Platform
The hardware and operating system that applications are run on

Premastering
In CD-ROM distribution, the process of preparing the data to be placed on the CD-ROM so that is optimally fits the CD-ROM format and limitations.

Primary color
In a tri-stimulus color video system, one of the three colors mixed to produce an image. In additive color systems, the primary colors are red, green, and blue. In subtractive color systems, the primaries are cyan, magenta, and yellow.

Production
In video refers to the process of creating programs. In more specific usage, production is the process of getting original video onto tape or film and ready for post- production.

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CD Optical Storage Glossary of Computer Terms (Letter O)

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ODBO
bject Database. A database that can handle diverse and complex data including video images, audio, bit maps, graphics and unstructured text.

Opacity
Term used to describe the amount an editing technique effects a given area of an image. Opacity in commonly expressed in percentages an can be used to simulate watercolor wash or in sequence segments to fade or dissolve

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