Cluster states

This topic describes SAN File System cluster states.

SAN File System cluster states can be active, inactive, or unknown.

Table 1. SAN File System cluster states
State type State name State description
Inactive Not running 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.
Forming The cluster has a cluster master and is in the process of forming. This state is always the initial one whenever a cluster is newly formed.
Active Offline One or more servers in the cluster are in the "Offline" state. This state terminates all current client sessions and prevents new client sessions from being started, but still allows all server I/O. The offline state is used for restricting the cluster from client access.
Characteristics:
  • No cluster configurations are allowed in this state. Configuration changes will fail.
  • Metadata activity stops.
  • Existing locks are maintained.
  • File extensions (growing a file) are not allowed during this time, which guarantees a consistent metadata view for LUN-based backup.
  • Only existing USER data blocks from client side can be modified and assume client-application based techniques are used to make that data consistent later.
  • SAN File System FlashCopy® image activity is available.
  • Administration command line interface client locks are revoked, caches flushed, and so on.
Fully quiescent One or more servers in the cluster are in the “Fully Quiescent” state. Quiescence puts the cluster in a “quiet” client communications mode to allow other operations to occur, such as configuring a cluster or creating a FlashCopy image. Full quiescence cuts off all client communications with the cluster.
Characteristics:
  • SAN File System FlashCopy image activity is available.
  • No cluster configurations are allowed in this state. Configuration changes will fail.
  • Administration command line interface client locks are revoked, caches flushed, and so on.
Partly quiescent One or more servers in the cluster are in the “Partly Quiescent” state. Quiescence puts the cluster in a “quiet” client communications mode to allow other operations to occur, such as configuring a cluster or creating a FlashCopy image. Partial quiescence allows existing metadata activity and client communication to continue, but prohibits new communication.
Online All servers in the cluster are in the “Online” state, meaning that the cluster has fully initialized all of its subsystems, and is serving client requests.
Unknown Unknown The cluster state cannot be determined.

Parent topic: States

Related concepts
Metadata server

Related tasks
Creating a FlashCopy image

Related reference
Managing the cluster
Metadata server states

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IBM TotalStorage SAN File System v2.2