Storage — page 5 of 9

Storage terms

401. LTO (Linear Tape-Open) A type of backup tape which can hold as much as 400 GB of data, or 600 CDs depending on the data file format.
402. Lubricant (LOO-brih-kant) An oily or slippery substance.
403. LUN Logical Unit Number. A logical unit of storage.
404. LUN (Logical Unit Number) A unique identifier used on a SCSI bus to distinguish between devices that share the same bus.
405. LUN Masking A method to restrict server access to storage not specifically allocated to that server.
406. LVD (Low Voltage Differential) Introduced with Ultra2 SCSI, and further enhanced with Ultra160 and Ultra320 SCSI, LVD technology enables data transfer to 320MB/s and supports cable…
407. LZW (Lempel-Ziv & Welch) A common, lossless compression standard for computer graphics, used for most TIFF files. Typical compression ratios are 4/1.
408. M by N A type of Symmetrix grouping in which up to two Symmetrix frames may be configured on either side of a data replication link in a Metrocluster/SRDF…
409. Magnetic particles The magnetic particles incorporated in the binder to form the magnetic layer on a magnetic tape.
410. Magnetic pigment See magnetic particles.
411. Magnetic remanence The strength of the magnetic field that remains in a tape or magnetic particle after it is (1) exposed to a strong, external magnetic field and (2) the…
412. Magnetic retentivity See magnetic remanence.
413. mailbox disk One of a set of disks owned by each filer that is used to store the cluster state information of the filer.
414. maintenance mode One of the options available when you boot a NetApp appliance from a system boot disk.
415. Management Information Base (MIB) ASCII files that describe the information that the SNMP agent sends to network management stations.
416. manual failover Failover requiring human intervention to start an application or service on another node.
417. Mb (Megabit) One million bits. Unit of measure for data transfer.
418. MB (Megabyte) 1,048,576 bytes, or 1,024 KB. Unit of measure for computer storage.
419. Mbps Megabits per second.
420. MD5 message-digest algorithm meant for digital signature applications where a large message has to be compressed in a secure manner before being signed with…
421. mean time between failures (MTBF) A measure of the reliability of an item. Defined as the total functioning life of an item divided by the total number of failures within the population…
422. mean time to repair (MTTR) The total elapsed time for corrective maintenance divided by the total number of corrective maintenance actions during a given period of time.
423. Megabyte A unit of information or computer storage abbreviated as M orMB, equal to 1,024 x 1,024 = 1,048,576 bytes.
424. Message Digest 5 (MD5) An algorithm for checksum generation for use in security applications. See also "RSA."
425. Metrocluster A Hewlett-Packard product that allows a customer to configure an Serviceguard cluster as a disaster tolerant metropolitan cluster.
426. metropolitan cluster A cluster that is geographically dispersed within the confines of a metropolitan area requiring right-of-way to lay cable for redundant network and data…
427. MIB Management Information Base. ASCII files that describe the information that the SNMP agent sends to network management stations.
428. Microprocessor A processor on the RAID card which performs all RAID management functions.
429. Microsoft Management Console (MMC) A GUI framework for management applications.
430. Microsoft Media Streaming (MMS) The streaming media control protocol used in Windows Media Technologies 3 and 4 streams.
431. MIME Multipurpose Internet Mail Extension.
432. Mirror A reflecting surface of various physical shapes (parabolic, nearly flat, or flat) used to reflect and/or concentrate the sun's energy to specific…
433. Mirror Site A file server containing a duplicate set of files located in a different geographic area for the purposes of managing heavy traffic, providing security…
434. mirrored data Data that is copied using mirroring.
435. mirroring The duplication of data for purposes of backup or to distribute Internet or network traffic among several servers with identical data.
436. mission critical application Hardware, software, processes and support services that must meet the uptime requirements of an organization.
437. mission critical solution The architecture and processes that provide the required uptime for mission critical applications.
438. Mistracking The phenomenon that occurs when the path followed by the read head of the recorder does not correspond to the location of the recorded track on the…
439. MMC A Microsoft management display framework that provides a unified view for administering multiple integrated network applications.
440. MMS Multi-Mode Seeker.
441. mount To make the file system on a particular device accessible by attaching it to the file hierarchy.
442. Mount Point A mount point is a directory on a volume that an application can use to "mount" (set up for use) a different volume.
443. MPOF (Multiple Points of Failure) More than one point of failure that can bring down an Serviceguard cluster.
444. MRH (Magneto-Resistive Head) a read head technology designed to support data acquisition from media with very high recording densities. See GMR.
445. MRTG Multi-Router Traffic Grapher. A Web-based tool for monitoring traffic and other SNMP variables on network connections. See also "Cricket."
446. MSBF (Mean Swaps Between Failures) the average number of swaps a jukebox or tape library can be expected to deliver before maintenance is required.
447. MTBF Mean Time Between Failures.
448. MTBF (Mean Time Between Failures) The average time between expected device failures.
449. MTDL (Mean Time until Data Loss) the average time until a component failure can be expected to cause data loss. This includes the consideration that RAID redundancy can protect against…
450. MTTR Mean Time To Repair.
451. MTTR (Mean Time To Repair) Average time to repair. The higher the number, the more costly and difficult to fix.
452. Multi-Router Traffic Grapher (MRTG) A Web-based tool for monitoring traffic and other SNMP variables on network connections. See also "Cricket."
453. Multipathing Multipathing is the use of redundant storage network components responsible for transfer of data between the server and storage.
454. multiple system high availability Cluster technology and architecture that increases the level of availability by grouping systems into a cooperative failover design.
455. mutual recovery configuration A continental cluster configuration in which each cluster serves the roles of primary and recovery cluster for different recovery groups.
456. MVC (Multiple Volume Cartridge) a "real" physical cartridge that contains multiple virtual volumes.
457. name server A network server that provides a directory service. See also "DNS," "NIS," and "WINS."
458. NAP NDS Augmentation Package.
459. NARA The abbreviation for National Archives and Records Administration.
460. NAS (1) National Academy of Sciences, Washington, DC. (2) Naval Air Station.
461. NAS (Network Attached Storage) NAS provides storage resources to servers and workstations over a shared or dedicated network.
462. NCS (Nearline Control Solution) an MVS-based StorageTek software product that supports more than 16 MVS images sharing a single library complex.
463. NDMP Network Data Management Protocol. A communications protocol for backing up data in a heterogeneous environment.
464. NDMP (Network Data Management Protocol) A communication protocol that standardizes command and control functions, allowing a central backup application to seamlessly backup different file…
465. Nearline Storage Secondary storage, typically disk-based, that offloads reference data from primary storage resources, yet, unlike archived storage, allows quick access to…
466. NetApp The trademarked short form for Network Appliance, Inc.
467. NetCache The proprietary software that runs on NetCache appliances. Developed by Network Appliance.
468. NetCache appliance An appliance designed specifically to serve Internet and intranet content quickly and reliably. Developed by Network Appliance.
469. NetCache Manager The browser interface through which a NetCache appliance is managed.
470. network access point (NAP) Traditionally the point at which an entity connects to the public Internet; but the term generically applies to any point of entry to a WAN.
471. network adapter A printed circuit board that connects a computer or other node to a network. Also known as a "network interface card" or "NIC."
472. network attached storage (NAS) A file-storage device that is accessed through a network.
473. Network Data Management Protocol (NDMP) A communications protocol for backing up data in a heterogeneous environment.
474. network failover The ability to restore a network connection after a failure in network hardware when there are redundant network links to the same IP subnet.
475. Network File System (NFS) The Network File System (NFS) protocol allows a given computer to access a disk on another computer over a network in a transparent fashion.
476. Network Information Service (NIS) An administrative database for networks. Formerly called Yellow Pages.
477. network interface card (NIC) A printed circuit board that connects a computer or other node to a network. Also known as a "network adapter."
478. network lock manager A facility that works with NFS to provide a System V-style of advisory file and record locking over the network.
479. network management station (NMS) A client workstation on a network that uses a third-party application (SNMP) to process status and diagnostic information.
480. network trace A facility for tracing the route of a computer that is connected to the Internet. See also "packet trace."
481. news cache A NetCache appliance configured to accept news requests from clients and to fetch requested news data from a news server or another NetCache appliance…
482. NFS Network File System, which allows you to mount a remote filesystem as if it were local.
483. Nibble A 4 Bit aggregation - or half an octet.
484. NIC National Intelligence Council.
485. NIC (Network Interface Card) Interface cards designed to transfer packetized file level data among PCs, servers and storage devices.
486. NIS Network Information Service. An administrative database for networks. Formerly called Yellow Pages.
487. NMS A life-threatening condition that may be caused by certain drugs used to treat mental illness, nausea, or vomiting.
488. nonvolatile random access memory (NVRAM) Type of computer memory that retains data in the event of a loss of power. In NetApp filers, NVRAM is used for logging incoming write data and requests.
489. normal mode The state of a filer when there is no takeover in the cluster.
490. Notification The third of five Early Warning System components consisting of communicating alerts and warnings about an emergency condition at a dam to appropriate…
491. NOW NetApp On the Web. The secure customer service Web site for Network Appliance.
492. NT domain A group of Windows NT systems that share a common database of security objects.
493. NT file system (NTFS) The Windows NT hierarchical file system.
494. NT LAN Manager (NTLM) A Windows NT authentication protocol; supported by NetCache.
495. NTAP The Network Appliance stock-ticker symbol on NASDAQ.
496. NTFS NT File System. The Windows NT hierarchical file system.
497. NTFS File System Designed exclusively for use with the Windows NT and later operating systems. NTFS allows for stronger security and more flexible file management methods…
498. NTFS permissions The permissions used in NTFS-style security to control access to files and directories.
499. NTLM NT LAN Manager. A Windows NT authentication protocol; supported by NetCache.
500. NTLM credential A message containing a challenge and response, sent from the browser to NetCache or from NetCache to a domain controller, for the purpose of…