Glossary

 < Day Day Up > 

Access control

Limiting access to resources according to rights granted by the system administrator, application, or policy.



Access time

The amount of time it takes for a controller to find and read data on a media.



Arbitrated loop

A Fibre Channel topology in which all nodes are connected in a loop, with frames passing from one node to the next.



Archive

Copying data, which is only occasionally accessed, to an off-line media.



Array

A device that aggregates large collections of hard drives into a logical whole.



Asynchronous

A process that is not coordinated in time. In data storage processes, asynchronous means that the device or software does not wait for acknowledgement before performing the next I/O.



Authentication

The process by which the identity of a user or process is verified.



Availability

The ability to access data or information on demand.



Backup

Making copies of data to a device other than the original data store.



Backup window

The interval in which backups can be performed without impacting other systems.



Block I/O

The type of I/O where a device or protocol accesses data on a disk as blocks of data without structure. Upper level protocols and applications are then responsible for building higher level constructs from the blocks.



Business continuity

The ability of a business to continue to operate in the face of disaster



Cascade failure

A catastrophic system failure where the failure of one system causes the failure of other systems.



CD-ROM/RW

Compact Disc Read-Only Memory and Compact Disc Read-Write. A mass storage medium that stores data on a small plastic disk. Originally used for music.



CIFS

The Common Internet File System. A protocol for accessing resources such as files and printers on a LAN.



Client

In client-server computing, the process that makes requests for information and then receives them.



Compression

The process of reducing the size of data by use of mathematical algorithms.



Content Addressed Storage (CAS)

A specialized storage device that locates and manages information based on its content.



Content Aware Storage

See [Content Addressed Storage]
Context

Other data that imparts meaning and structure to data.



Controller

An interface that allows mass storage devices to connect to a specific type of bus or network.



Data

An atomic element of information. Represented as bits within mass storage devices, memory, and processors.



Data corruption

An event where data is damaged.



Data Lifecycle Management (DLM)

The process by which data is moved to different mass storage devices based on its age.



Data migration

The movement of data from one storage system to another.



Data mover

An appliance that moves data from one storage device to another.



Data protection

The protecting of data from damage, destruction, and unauthorized alteration.



Data retention

Keeping data safe and available for some predetermined amount of time. Often a requirement of government regulations.



Defense in Depth

Having layers of security and detection systems to inhibit an intruder from gaining access to corporate systems and data.



Denial of Service (DoS)

A type of attack on a computer system that ties up critical system resources, making the system temporarily unusable.



Direct Access Storage Device (DASD)

A type of IBM mainframe mass storage device. The precursor to open Direct Attached Storage systems.



Direct Attach Storage (DAS)

A type of mass storage system where storage devices are attached directly to the system peripheral bus.



Director

Large storage networking switches with many ports and high availability features.



Disk-to-disk backup

Backup system based on hard drives rather than tape drives.



Disk-to-disk-to-tape backup

Three-tier backup system that first backs up to a disk, then to a tape.



Diversity of defense

Deploying many different methods of defense, in different layers.



Domain Naming Service (DNS)

A common name resolution system used extensively in internet systems. It associates an IP address with a common name.



Document Type Definitions (DTD)

A method of describing the structure of an XML document.



DVD-ROM/RW

Digital Video Disk, Read-Only Memory and Digital Video Disk Read-Write. A mass storage medium that stores data on a small plastic disk. Originally used for video.



Encryption

The encoding of data so that the plain text is transformed into something unintelligible, called cipher text.



Enterprise

Term used to describe formal organizations such as corporations. Often used to refer to the entire scope of an organization's IT systems.



Extended copy

A set of extensions to the SCSI protocol to control the movement of data between two other devices. Also known as Third-Party Copy, X-Copy, and E-Copy.



Failover

The ability of a secondary device to take the place of a primary device during failure of the primary device.



Fibre Channel

A type of network commonly used for Storage Area Networks. Fibre Channel encompasses hardware specifications and a set of protocols, well suited to performing block I/O in a network environment.



File head

A specialized server that presents mass storage devices as a filesystem on a network.



File I/O

Accessing data through a file system. Applications that do not access data directly as block rely on the file system to provide data in a format with a certain structure, called a file.



File system

A storage system layer that organizes data into general structures such as directories, folders, and files.



Filer

Another term for a NAS array. Originally a product name for NAS devices from Network Appliance.



Firewall

Software or devices that examine network traffic so that it may restrict access to network resources to unauthorized users.



Full backup

A backup of the entire hard drive or array.



Gigabit

1,073,741,824 bits. Used to describe transmission rates in data communications and networking.



Gigabit Ethernet

A networking technology with a transmission rate of one Gigabit or more.



Gigabyte

1024 Megabytes. Used as a unit of computer storage and to describe data transfer rates.



Hard drive

A mass storage device that deploys hard, revolving platters to provide persistent storage of data. Hard drives use magnetism as the method of encoding information on the platters.



Hash

A set of characters generated by running text data through certain algorithms. Often used to create digital signatures and compare changes in content.



High Availability (HA)

The ability of a device to continue operating in the event of component failures.



Host

(1) A computer that contains software or data that is shared through a network.

(2) In the SCSI protocol, the process that receives SCSI commands, processes them, and sends them back to an initiator.

(3) In general usage, a synonym for "client."



Host Bus Adapter (HBA)

A peripheral board or embedded processor used to connect a host's peripheral bus to the SCSI bus or Fibre Channel network.



I/O

Input/Output. The movement of data to or from some device or software element.



IDE/ATA

A mass storage specification and protocol common to desktop computers.



Image copy

A backup of an entire volume. Restoring from an image copy reproduces the entire volume at the point in time that the copy was made.



Incremental backup

Backups that only copy objects that have changed since the last backup.



Information

Information is data with context. It can be externally validated and is independent of applications.



Information assurance

The process by which an organization insures, protects, and verifies the integrity of vital information.



Information Lifecycle Management (ILM)

A strategic process for dealing with information assets. ILM is expressed as a strategy, which is used to generate policies. Finally, a set of rules is created to comply with the policies.



Information mover

A data mover combined with an ILM policy engine. It moves data in response to ILM events.



Information path

A way of describing where information is without subscribing to specific operating system nomenclature.



Information perimeter

The boundary beyond which an ILM policy cannot expect to have control over information.



Intrusion Detection System (IDS)

A device or software system that examines violations of security policy to determine if an attack is in progress or has occurred.



IPSec

An extension to the Internet Protocol that allows for encrypted messaging. Used extensively in secure communications.



iSCSI

A networked version of SCSI that transmits block data over an IP network.



IT

Information technology. A broad term that encompasses a range of technology that is used to manipulate information. Also used to refer to the industry that develops information technology products and the function within organizations that manages information technology assets.



Jukebox

A device that aggregates CD and DVD drives into a larger system.



Latency

The amount of time it takes a system to deliver data in response to a request. For mass storage devices, it is the time it takes to place the read or write heads over the desired spot on the media. In networks, it is a function of the electrical and software properties of the network connection.



Lightweight Directory Access Protocol (LDAP)

A protocol for accessing online directories. LDAP directories may contain all types of directory information, including host addresses.



Least privilege

The maximum amount of access any user, host, or processor should have to system resources.



LIP

Loop Initialization Primitive. A low-level Fibre Channel command that begins the process of loop reconfiguration in Arbitrated Loop topologies.



Load balancing

A method of assuring availability and performance where two devices or components share the processing load. It is also used as a failover technique in which failure of one device simply increases the load of the other devices.



LUN

Logical Unit Number. A SCSI protocol sub-address used to increase the overall number of addressable elements in a SCSI system.



LUN locking

Restricting access to LUNs to specific SCSI initiators. Used to keep unauthorized hosts from accessing storage resources.



LUN masking

The ability to hide SCSI LUNs from unauthorized initiators. The LUNs are still accessible but will not respond to a SCSI Inquiry command.



Magneto-optical disk

A mass storage device, which combines the properties of magnetic and laser-based disks.



Metropolitan Area Network (MAN)

A campus or city-wide network, usually based on optical networks such as SONET.



Media

Objects on which data is stored.



Megabit

Approximately 1024 thousand bits. Used to describe network transmission rates.



Megabyte

1024 thousand bytes. A unit of measure of mass storage used to describe data transfer rates (megabytes per second).



Metadata

Data that describes other data.



MIME type

Multipurpose Internet Mail Extensions. A method of describing the type of a document or object transmitted over Internet systems. Used extensively by e-mail and web applications.



Mirroring

Copying the same data block to different disks in order to have a copy of the block available in the event of a disk failure.



MIS

Management Information Systems. A subset of information technology, MIS is an older term that refers to the IT functions within companies.



MP3

Moving Picture Experts Group Layer-3. A standard format for encoding audio and video. Popular as a way of digitizing music so that it can be played on digital devices such as computers.



NAS head

See [File head]
Network Attached Storage (NAS)

A self-contained, highly optimized file server. NAS devices support common network interfaces and file transfer protocols such as NFS and CIFS.



Network Data Management Protocol (NDMP)

A bi-directional communication, based on XDR and a client-server architecture, optimized for performing backup and restore.



Network File System (NFS)

A common networked file system originally from Sun Microsystems. NFS is a common way of sharing data on UNIX and LINUX systems.



Non-disruptive failover

A failover technique that maintains I/Os in progress and completes all transactions, as if the failure had not occurred.



Policy

A set of best practices that the organization must follow. Policies are a concrete expression of a strategy.



Policy engine

A system that stores and executes the tasks, references, and constraints that express a DLM or ILM policy in terms that computer systems can understand.



Quality of Service (QoS)

The guaranteed performance of a network connection.



RAID

Redundant Array of Independent Disks. A schema for using groups of disks to increase performance, protect data, or both.



RAID level

The different types of RAID functions. RAID levels are expressed with a numbering system of 0, 1, 3, 5, 7, and 10.



Read head

The part of a mass storage system that retrieves data off of the media.



Recovery

The process by which data is retrieved from a backup and copied to a primary storage device.



Recovery Point Objective (RPO)

The point in time to which data must be restored.



Recovery Time Objective (RTO)

Following a disaster, the amount of time that a system may be offline before it must be up and running.



Remote copy

The duplication of I/O from one set of disks to another similar set, on a block level.



Replication

The duplication of I/O from one set of disks to another similar set, on a file level.



Restore

See [Recovery]
Schema

A description of data that provides context and structure. There are many types of schemas, including database schemas and XML schemas.



SCSI

Small Computer Systems Interface. A specification for both hardware and software protocols, used to transfer data between peripheral devices and the peripheral bus in a computer.



SCSI initiator

In SCSI systems, the device that issues commands and requests data block.



SCSI target

In SCSI systems, the device that receives commands and returns requested data blocks.



Security posture

The core philosophy or approach applied to a security plan. The two most common postures are referred to as Default DENY and Default ALLOW.



Serial ATA (SATA)

A serial version of ATA technology.



Serial Attached SCSI (SAS)

A serial version of SCSI technology. Fibre Channel SCSI and iSCSI are also serialized versions of SCSI, but are designed for specific network environments. SAS is designed for its own hardware layer.



Snapshot

A point-in-time virtual copy of the file system.



Solid state storage

A type of mass storage device that uses RAM to store data.



Spoofing

An intrusion technique that replaces a legitimate address with one provided by an attacker.



State

In ILM, this describes content and metadata (context) at a specific point in time.



Stateful failover

See [Non-disruptive failover]
Storage Area Network (SAN)

A storage system architecture that defines methods for performing block I/O over a high-speed network.



Storage switch

A switching device designed primarily with storage applications in mind. Fibre Channel switches and iSCSI-optimized Ethernet switches are often referred to as storage switches.



Streaming

To transfer data continuously from a device.



Switched fabric

A Fibre Channel topology that uses a switch to provide full bandwidth connections to all ports.



Synchronous

A process that is coordinated in time. In data storage processes, synchronous means that the device or software waits for acknowledgement before performing the next I/O.



Tape drive

A mass storage device that transfers data to and from magnetic tape.



TCP/IP

Transmission Control Protocol and Internet Protocol. Networking protocols common to most forms of networks. TCP provides for synchronous communications over IP.



Transfer time

The amount of time it takes the disk, tape, or other storage to transfer data from off the media and onto the data bus or network.



Trunking

Aggregating redundant network connections to provide more network bandwidth.



UML

Unified Modeling Language. A language that describes the design, modeling, and deployment of systems. Commonly used in software design, UML also has broader application for describing systems.



Virtual Private Network (VPN)

A connection made over a public or internal network, which uses encryption to provide security. A VPN provides the security of a private connection over an insecure network.



Virtual tape

The emulation of a tape system by a disk-based system. Virtual tape provides backup software with the same interface for a disk system as for a tape system.



Volume

A virtual set of blocks. A volume aggregates blocks from one or many disks into a single logical whole.



Volume manager

Software that creates and manages volumes.



WAN

Wide Area Network. A network topology designed to connect devices over very long distances, typically outside the limits of a single campus or city.



World Wide Name

A unique 64-bit identifier used as an address by Fibre Channel systems.



Write head

The part of a mass storage system that places data on the media.



XML

Extended Markup Language. A markup language that defines the structure of data through the use of paired tags. Commonly used in software protocols and web pages to store moderate amounts of information.



Zoning

A method of limiting access to resources in Fibre Channel networks. Zoning masks resources from hosts not in the same zone.



     < Day Day Up > 


    Data Protection and Information Lifecycle Management
    Data Protection and Information Lifecycle Management
    ISBN: 0131927574
    EAN: 2147483647
    Year: 2005
    Pages: 122

    flylib.com © 2008-2017.
    If you may any questions please contact us: flylib@qtcs.net