This glossary includes terms and definitions from:
This glossary uses the following cross-reference forms:
- See
- This refers the reader to one of two kinds of related information:
- A term that is the expanded form of an abbreviation or acronym. This expanded
form of the term contains the full definition.
- A synonym or more preferred term
- See also
- This refers the reader to one or more related terms.
- ACLI
- See administrative command-line interface (ACLI).
- administrative command-line interface (ACLI)
- A command-line interface used to administer all aspects of the SAN File
System. The ACLI runs on all engines that host metadata servers and the administrative
server.
- administrative log
- A log that maintains a history of messages created by the administrative
server.
- administrative server
- For SAN File System, a set of servlets running within a customized instance
of WebSphere® Application
Server that handles all SAN File System administrative requests from the SAN
File System console. See also SAN File System console.
- alert
- A message or other indication that identifies a problem or an impending
problem.
- audit log
- A log that maintains the history of all commands issued by any administrator
for all metadata servers in the cluster.
- CIM
- See Common Information Model.
- CIM client application
- A storage management program that initiates CIM requests to the administrative
agent for the device.
- CIM namespace
- The scope within which a CIM schema applies.
- CIM object manager (CIMOM)
- The common conceptual framework for data management that receives, validates,
and authenticates the CIM requests from the client application and then directs
the requests to the appropriate component or device provider.
- CIMOM
- See CIM object manager.
- client
- For SAN File System, a client is a system that can access the SAN File
System. These clients act as servers to a broader clientele, providing Network
File System or Common Internet File System access to the global namespace
or hosting applications (such as database servers or Web-hosting services
that use multiple servers).
- class
- The definition of an object within a specific hierarchy. An object class
can have properties and methods and serve as the target of an association.
- CLI
- See Administrative command-line interface.
- client state manager (CSM)
- A component of the client kernel that provides protocol support for the
client.
- cluster
- A group of engines that is managed as a set and presents a single point
of control for configuration and service activity.
- cluster log
- A log that maintains a history of messages created by all metadata servers
in the cluster.
- cluster state
- A status condition of the cluster. Cluster states can be inactive (Not
running or Forming), active (Online, Offline, Partly quiescent, or Fully quiescent)
or unknown. See also Forming, Fully quiescent, Not running, Offline, Online, and Partly
quiescent.
- Common Information Model (CIM)
- A set of standards from the Distributed Management Task Force Inc. (DMTF).
CIM provides a conceptual framework for storage management and an open approach
to the design and implementation of storage systems, applications, databases,
networks, and devices.
- coordinated universal time (UTC)
- The time scale, based on the System International (SI) second, as defined
and recommended by the Comitb Consultatif International de la Radio (CCIR)
and maintained (using an atomic clock) by the Bureau International des Poids
et Mesures (BIPM).
- CSM
- See client state manager.
- default user storage pool
- A storage pool that stores file data that SAN File System has not assigned
(using the active policy) to a user storage pool, as well as file data that
is assigned directly to this storage pool. There is only one default user
storage pool; however, you can assign any user storage pool as the default
storage pool. See also user storage pool
- engine
- The hardware unit that hosts the software for the metadata server.
- event log
- A log that maintains a history of event messages issued by all metadata
servers in the cluster.
- IBM® Term:
A log that contains information about events for a particular system or group,
for a particular metric, or for all the events that are associated with a
specific monitor.
- failover
- The automatic recovery of resources in the event of a network outage,
or failure of the hardware or software.
- file-placement rule
- A rule that controls in what pool SAN File System places files in the
global namespace. See also rule and global namespace.
- fileset
- A hierarchical grouping of files managed as a unit for balancing workload
across a cluster.
- FlashCopy® image
- A space-efficient image of the contents of part of the SAN File System
at a particular moment.
- Forming
- A status condition where the cluster has a master and is in the process
of forming. This state is always the initial one whenever a cluster is newly
formed.
- Fully quiescent
- A status condition that cuts off all client communication with the cluster.
- global namespace
- A single file system that provides complete, shared access to both Windows® and UNIX® clients
in the same environment.
- ID
- See identifier.
- identifier (ID)
- A sequence of bits or characters that identifies a user, program, device,
or system to another user, program, device, or system.
- Initializing
- A status condition during which a metadata server or the entire cluster
is set up for the first time.
- key
- A property that is used to provide a unique identifier for an instance
of a class. Key properties are marked with the Key qualifier. (D)
- lease
- The amount of time that a client can hold a lock.
- lock
- A restriction that allows clients to have exclusive access to files. Types
of locks include data locks, session locks, and range locks.
- logical unit (LU)
- In open systems, a logical disk drive.
- logical unit number (LUN)
- In the small computer system interface (SCSI) protocol, a unique number
used on a SCSI bus to enable it to differentiate between up to sixteen separate
devices per SCSI ID address, each of which is a logical unit.
- LU
- See logical unit.
- LUN
- See logical unit number.
- managed object format (MOF)
- A compiled language for defining classes and instances. A MOF compiler
offers a textual means of adding data to the CIM Object Manager repository.
MOF eliminates the need to write code, thus providing a simple and fast technique
for modifying the CIM Object Manager repository. (D)
- master metadata server
- In SAN File System, the metadata server in a cluster that is responsible
for physical-space allocation.
- metadata
- Data that describes the characteristics of stored data; descriptive data.
- metadata server
- In SAN File System, a server that offloads the metadata processing from
the data-storage environment to improve SAN performance. An instance of the
SAN File System runs on each engine, and together the metadata servers form
a cluster. See also cluster.
- method
- A way to implement a function on a class.
- MOF
- See managed object format.
- Not running
- A status condition where one or more servers in the cluster are not added
and therefore the cluster cannot perform any functions.
- OBDC
- See one-button data collection.
- object name
- An object that consists of a CIM namespace path and a model path. The
namespace path provides access to the CIM implementation managed by the CIM
agent, and the model path provides navigation within the implementation.
- Offline
- A status condition during which clients are not being serviced and the
cluster is responding only to administrative requests.
- one-button data collection
- A utility that gathers data for diagnosing errors or failures
associated with metadata servers and clients. It is intended primarily for
first-failure data-capture capabilities useful for investigating problems
upon their initial occurrence, without requiring problem recreation or subsequent
tracing.
- Online
- A status condition that indicates the normal operational state for the
cluster.
- Partly Quiesced
- A state in which the cluster or server is in a “quiet” client communications
mode to allow other operations to occur.
- Partly quiescent
- A status condition that allows existing metadata activity and client communication
to continue on the cluster, but prohibits new communication.
- policy
- A list of file-placement rules that define characteristics and placement
of files. Several policies can be defined within the configuration, but only
one policy is active at one time. See also file-placement rule and service-class
rule.
- pool
- See storage pool.
- property
- An attribute that is used to characterize instances of a class.
- qualifier
- A value that provides additional information about a class, association,
indication, method, method parameter, instance, property, or reference.
- quota
- A limit on the amount of disk space a user can use.
- root squashing
- The process of a root or Administrator user logging into a client that
is not a privileged client.
- rule
- The lines within a policy that specify which actions will occur when certain
conditions are met. Conditions include attributes about an object (file name,
type or extension, dates, owner, and groups) and the fileset name associated
with the object.
- SAN File System console
- A Web user interface used to monitor and control the SAN File System remotely
by using any standard Web browser.
- schema
- A group of object classes defined for and applicable to a single namespace.
Within the CIM agent, the supported schemas are loaded through the managed
object format (MOF) compiler.
- security log
- A log that maintains a history of administrative server login activity.
- service location protocol
- A directory service that the CIM client application calls to locate the
CIMOM.
- Shutdown
- A status condition that describes when the cluster is shut down as intended.
- SLP
- See service location protocol.
- Starting
- A status condition when a metadata server is starting as designed but
is not ready to accept connections from clients.
- storage pool
- A named set of storage volumes that is the destination for storing client
data.
- symbolic link
- A type of file that contains the path name of and acts as a pointer to
another file or directory.
- system storage pool
- A storage pool that contains the system metadata (system and file attributes,
configuration information, and metadata server state) that is accessible to
all metadata servers in the cluster. There is only one system storage pool.
See also metadata server.
- user storage pool
- An optional storage pool that contains blocks of data that compose the
files that are created by SAN File System clients. See also storage pool and default
user storage pool.
- volume
- A labeled logical unit, which can be a physical device or a logical device.
For SAN File System, there is a one to one relationship between volumes and
LUNs. See also logical unit number.
- UTC
- See coordinated universal time