Acronyms

Acronyms are horrible things - they tend to create a layer of obfuscation that confuses new users, allows knowledge and understanding to diverge from reality as original meanings get lost and forgotten, and can be used by some to imply some kind of knowledge superiority over their peers. Unfortunate they are rife in IT (!), and systems and techniques are often given unnecessarily long or complex names in order to create a good acronym...

A

• AD - Active Directory
• ALUA - Asymmetric Logical Unit Access, SAN feature whereby connected hosts can determine the states of target ports and prioritise paths to use to access LUN's
• AP - Asia Pacific
• API - Application Programming Interface, used to allow a 3rd party access to an application via software/script
• ASCII - American Standard Code for Information Interchange, character encoding system
• ASLR - Address Space Layout Randomisation, security feature that randomises data layout in memory
• ASR - Automated System Recovery, HP feature to reboot hardware in the case of the OS failing
• ATA - AT Attachment (disks), also known IDE or EIDE

B

• BCS - British Computer Society
• BGP - Border Gateway Protocol, a routing protocol
• BSOD - Blue Screen of Death, as seen on Windows servers

C

• CDB - SCSI Command Descriptor Block
• CIFS - Common Internet File System
• CIM - Common Information Model
• CMDB - Configuration Management Database
• CRAC - Computer Room Air-Conditioning
• CRC - Cyclic Redundancy Check, allows for error detection (without recovery)

D

• DCE - Data Communications Equipment, eg modem
• DHCP - Dynamic Host Configuration Protocol
• DMA - Direct Memory Access, allows components direct access to system memory (rather than through the CPU)
• DNS - Domain Name System
• DTE - Data Termination Equipment, eg router

E

• ECC - Error Checking Code, allows for error detection and some recovery of errors
• EIDE - Enhanced IDE (drive), approximately equivalent of ATA-2
• EMEA - Europe, Middle-East, Asia

F

• FATA - Fibre-Channel ATA disks, slower disks with FC interface
• FC - Fibre-Channel, normally used to connect servers with remote storage
• FOSS - Free and Open Source Software
• FQDN - Fully Qualified Domain Name, eg vwiki.sandfordit.com as opposed to vwiki
• FTP - File Transfer Protocol, uses TCP 20 and 21
• FTPS - Secure version of FTP, FTP over SSL/TLS, (not to be confused with SFTP)

G

• GPO - Group Policy Object
• GUI - Graphical User Interface

H

• HBA - Host Bus Adapter, server interface used to connect to SAN based storage
• HTTP - HyperText Transport Protocol, the bread and butter of the internet
• HTTPS - Secure HTTP, HTTP over SSL or TLS. Used for secure websites, and for delivering API and SOAP services

I

• IDE - Integrated Drive Electronics, aka ATA version 1
• IMAP - Internet Message Access Protocol, mailbox access protocol
• IP - Internet Protocol
• IPMI - Intelligent Platform Management Interface, open standard for managing hardware platforms
• iSCSI - IP Small Computer Serial Interface, SCSI over IP
• ISEB - Information Systems Examinations Board
• ITIL - IT Infrastructure Library

J

• JBOD - Just a Bunch of Disks

K

L

• LAN - Local Area Network
• LDAP - Lightweight Directory Access Protocol
• LDS - Lightweight Directory Services

M

• MAN - Metropolitan Area Network, somewhere between a LAN and a WAN, for example connecting buildings within a localised area
• MPLS - Multi Protocol Label Switch(ing)
• MSCS - Microsoft Clustering Services

N

• NAS - Network Attached Storage, storage that's available via a network
• NTP - Network Time Protocol, reliable time sync protocol, uses UDP 123

O

• OSPF - Open Shortest Path First, dynamic routing protocol
• OVA - Open Virtualisation Appliance, single file TAR of an OVF
• OVF - Open Virtualisation Format, industry standard virtual appliance definition, made up of various files within a folder

P

• PATA - Parallel ATA (disks, newer name for ATA disks)
• PCRE - Perl Compatible Regular Expressions, a widely used Regex system
• PDU - Protocol Data Unit, a unit or package of data. For example an SNMP Get request is a PDU
• PID - Process ID, number assigned by the OS to a running process
• POSIX - Portable Operating System Interface, cross OS standards for API's, etc
• PSOD - Purple Screen of Death, as seen on ESX servers
• PVLAN - Private VLAN, VLANs over VLANs

Q

R

• RAM - Random Access Memory - read/write memory
• RDP - Remote Desktop Protocol
• REST (API) - Representational State Transfer, web service
• RIP - Route Information Protocol, old school routing protocol
• ROM - Read Only Memory
• RSS - Really Simple Syndication, news feed protocol

S

• SAN - Storage Area Network, architecture for connecting systems to centralised storage
• SAS - Serial Attached SCSI (disk)
• SATA - Serial Advanced Technology Attachment (disk)
• SCOM - System Centre Operations Manager, Microsoft monitoring and operations product
• SCP - SSH Copy, provided by SSH v1 (has weaknesses and is outdated, SFTP provided by SSH v2 is current))
• SCSI - Small Computer Serial Interface
• SFTP - SSH File Transfer Protocol, secure copy provided by SSH v2 (not to be confused with FTPS)
• SLP - Service Locator Protocol]
• SMB - Server Message Block (aka CIFS), typically used to access shared file-systems and printers
• SMTP - Simple Mail Transfer Protocol, email message delivery protocol, uses TCP 25
• SNMP - Simple Network Management Protocol, used to monitor and manage network based devices by either polling of the device, or by the device generating traps (alerts)
• SNTP - Simple Network Time Protocol, lightweight version of NTP that doesn't include error checking etc
• SOAP - Simple Object Access Protocol, used to deliver remote services, usually over HTTP or HTTPS
• SPD - Serial Presence Detect, counter of errors experienced by a RAM memory stick, recorded on the stick
• SQL - Structure Query Language
• SSH - Secure Shell, used to access network devices securely over TCP 22
• SVN - SubVersioN, a version control system

T

• TAR - Tape Archive, a collection of files bundled together into a container file (historically used for backups)
• TCP - Transmission Control Protocol, networking transport of the internet
• TFTP - Trivial FTP, lightweight FTP using UDP 69
• TLB - Translation Lookaside Buffer, a cache mapping virtual memory addresses to physical addresses
• TLS - Transport Layer Security, successor to SSL

U

• UPS - Uninterruptable Power Supply
• UUID - Universally Unique ID

V

• VCP - VMware Certified Professional, title for certification on VMware Virtual Infrastructure / vSphere
• VI3 - VMware Infrastructure 3, the name given to an infrastructure running ESX3(i) host servers managed by Virtual Centre v2
• VI4 - VMware Infrastructure 4, officially called vSphere, the name sometimes given to an infrastructure running ESX4(i) host servers managed by vCentre v4
• VIC - (VMware) Virtual Infrastructure Client
• VIM - Virtual Infrastructure Manager, old name for VMware vCentre
• VLAN - Virtual LAN, allows different networks to be carried across the same Ethernet, differentiated by 802.1Q tags
• VMDK - Virtual Machine Disk file, a VMware virtual machine's virtual hard drive file
• VMFS - Virtual Machine File System, VMware's storage format for virtual machines to run on
• VNC - Virtual Network Computer, superior remote desktop application
• VPN - Virtual Private Network
• VRF - Virtual Routing and Forwarding, used to provide selective/conditional routing
• VSS - Volume Shadow Service, Microsoft OS service that creates quiesced disks (aka snapshots)

W

• WAN - Wide Area Network

X

Y

Z

• ZCA - Appliance version of a ZCS
• ZCS - Zimbra Collaboration Suite