This glossary defines technical terms and abbreviations used in SAN File
System documentation. If you do not find the term you are looking for, refer
to the index of the appropriate DFSMS manual or view the Glossary of Computing
Terms located at: http://www.ibm.com/ibm/terminology/.
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 routine activities and error
conditions that are generated by the administrative servers.
- 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 that modify
metadata or configuration data and significant operations, including commands
that would have made a change but failed to do so.
- CIFS
- See Common Internet File System.
- 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).
- 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 metadata servers 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 routine activities and error
conditions that are generated 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.
- Common Internet File System (CIFS)
- A protocol that enables collaboration on the Internet by defining a remote
file-access protocol that is compatible with the way applications already
share data on local disks and network file servers.
- container
- See fileset.
- 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
- dynamic fileset
- A fileset that is dynamically assigned to a metadata server by SAN File
System.
- 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. It is a subset of the cluster log.
- 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 metadata
- Information about the file, such as owner, permission, and physical location.
This information is stored in the system storage pool.
- file-management rule
- A rule that controls into what storage pool SAN File System moves a file
in the global namespace or whether to delete a file. See also rule and global
namespace.
- file-placement rule
- A rule that controls in what storage 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 fileset
- The root fileset in the global namespace.
- global namespace
- A single file system that provides complete, shared access to both Windows® and UNIX® clients
in the same environment.
- ID
- See identifier.
- initializing
- A status condition during which a metadata server or the entire cluster
is set up for the first time.
- lease
- The amount of time that a client can hold a lock.
- Lightweight Directory Access Protocol (LDAP)
- An open protocol that uses TCP/IP to provide access to directories that
support an X.500 model and that does not incur the resource requirements of
the more complex X.500 Directory Access Protocol (DAP). For example, LDAP
can be used to locate people, organizations, and other resources in an Internet
or intranet directory.
- 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 console
- In a system with multiple consoles, the basic console used for communication
between the operator and the system.
- master metadata server
- In SAN File System, the metadata server in a cluster that is responsible
for physical-space allocation.
- master volume
- The first volume assigned to the system storage pool that stores the most
critical system metadata.
- metadata
- The 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.
- metadata server log
- A log that maintains a history of routine activities and error conditions
that are generated by a metadata server.
- MOF
- See managed object format.
- Network File System (NFS)
- A protocol, developed by Sun Microsystems, Incorporated, that allows any
host in a network to mount another host's file directories. After a file directory
is mounted, it appears to reside on the local host.
- not running
- A condition in which the cluster cannot perform any functions because the master metadata server has not completed the start up
procedure to the point where the cluster is able to service
filesets or perform administration functions.
- A status condition where the metadata server is not running and cannot
perform any functions.
- OBDC
- See one-button data collection.
- 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 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 rules that define placement or management 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 file-management rule.
- pool
- See storage pool.
- primary administrative server
- The administrative server that runs on the same engine as the master metadata
server. It processes all administrative requests that are initiated from the
SAN File System console and those requests initiated from the ACLI that are
logged into the master metadata server.
- quota
- A size limitation, such as the limit on the amount of disk
space or size of a fileset.
- remote access
- A serviceability feature that enables remote IBM service personnel to
access the system to assist in diagnosing and resolving problems.
- Remote Supervisor Adapter II (RSA II)
- A high-performance PCI adapter that provides remote access to and control
of xSeries servers, including remote management independent of server status,
remote control of hardware and operating systems, and remote updates.
- rogue metadata server
- A metadata server that is not reachable from the cluster, fails to respond
to requests, and might be running or have latent queued I/O.
- 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.
- secondary administrative server
- The administrative server that runs on the same engine as a subordinate
metadata server and processes only those administrative requests that are
initiated from the administrative command-line interface (CLI) that is logged
into that subordinate metadata server.
- security log
- A log that maintains a history of administrator login activity
generated by the administrative server.
- service alert
- A serviceability feature that automatically notifies the IBM Support Center
about a problem that occurred.
- 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.
- Simple Network Management Protocol (SNMP)
- In the Internet suite of protocols, a network management protocol that
is used to monitor routers and attached networks. SNMP is an application-layer
protocol. Information on devices managed is defined and stored in the application's
Management Information Base (MIB).
- Simple Network Management Protocol (SNMP) trap
- In the Simple Network Management Protocol (SNMP), a message sent by a
managed node (agent function) to a management station to report an exception
condition. See also simple network management protocol.
- SLP
- See service location protocol.
- spare metadata server
- An idle metadata server that has no statically assigned filesets. It is
used for failover to take on the workload of another metadata sever that goes
off-line.
- starting
- A status condition when a metadata server is starting as designed but
is not ready to accept connections from clients.
- static fileset
- A fileset that is manually assigned to a specific metadata server by the
administrator.
- storage pool
- A named set of storage volumes that is the destination for storing client
data.
- system metadata
- Information that is create and managed by the metadata server, such as
information about filesets, storage pools, volumes and policies. This information
is stored in the system storage pool.
- 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.
- trace log
- A log that maintains of history of trace activity on the 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
- worldwide node name
- A unique 64-bit identifier for a host containing a fibre-channel
port. See also worldwide port name.
- worldwide port name
- A unique 64-bit identifier associated with a fibre-channel
adapter port. The WWPN is assigned in an implementation-independent and protocol-independent
manner.
- WWNN
- See worldwide node name
- WWPN
- See worldwide port name