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Maintenance Commands

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gabconfig - Group Membership and Atomic Broadcast (GAB) configuration utility


/sbin/gabconfig [-abcejklsuUvx] [-f iofence] [-h interval] [-m count] [-n count ] [-t stable ]


The gabconfig utility sets up and maintains the configuration of the GAB driver. The GAB driver is dependent on the Low Latency Transport (LLT) protocol, which must be configured prior to running gabconfig.


Display GAB driver port memberships.
Enable system halt when the process fails to heartbeat. By default, if a process fails to heartbeat in a given interval, GAB makes five attempts to kill the process. With this option set, GAB panics the system without making any attempts to kill the process. This option can be turned off using the -B option.
Disable system halt when the process fails to heartbeat. This option will turn off the functionality enabled by the -b option.
Print out kernel tunables set for GAB. If the value of the tunables is changed, the changed value will get into effect on module reload.
Configure the driver for use. Configuring the GAB driver enables client registrations and the joining of an already seeded group.
Enable halt on rejoin. A network failure may cause systems to form independant clusters, or partitions. When the connections are restored, systems will attempt to rejoin into one cluster. By default, GAB kills processes associated with ports on rejoining systems. This option directs GAB to halt the system.
Disable halt on rejoin. This option will turn off the functionality enabled by the -j option.
Repeat attempts to kill a process that does not die. By default, after five attempts to kill a process, GAB halts the system. This option directs GAB to close the client port and repeatedly and silently attempt to kill a process without halting the system.
Display the GAB driver configuration.
Single network. This flag disables network partition arbitration and should be used only to test configurations. It is required for operating GAB over one network connection with no alternative communication path, such as heartbeat disks.
Unconfigure the GAB driver. Close the seed control port (port a) if all client ports are closed.
Unconfigure the GAB driver and reinitialize all configuration states, including disk and seed configurations.
Display GAB version information like the product version, build time stamp, interface version, minimum, maximum, and on-the-wire protocol versions.
Seed control port. This option affords protection from pre-existing network partitions. The control port (port a) propagates the seed to all configured systems. GAB must be seeded to enable the delivery of membership on client ports.
-f iofence_timeout
Specify a timeout (in milliseconds) for clients to respond to an IOFENCE message before the system halts. When clients receive an IOFENCE message, they must unregister from the GAB driver within iofence_timeout milliseconds to avoid halting the system. The default is 15000ms or 15 seconds.
-h heartbeat_interval
Disk heartbeating interval, in milliseconds. If heartbeat disks are configured, this parameter monitors connectivity through the disk. The default is 1000ms or 1 second.
-m disk_heartbeat_miss_count
The number of disk heartbeats that can be missed before the disk or path is declared unavailable. The default is 4.
-n system_count
Count of systems in the cluster. A non-zero system count auto-seeds the cluster when all systems are present. The default is zero, for no auto-seeding.
-t stable_timeout
Specifies the time GAB waits to reconfigure membership after the last report from LLT of a change in the state of local node connections for a given port. Any change in the state of connections will restart GAB waiting period. stable_timeout applies during membership transitions. The default value for stable_timeout is five seconds. Note that message latency for connection state messages, typically less than one second, should be taken into consideration when calculating stable_timeout value.


Manual editing of the GAB and LLT configuration files is not recommended. Refer to the documentation for your clustering solution for information and guidelines on configuring LLT and GAB. -k, -b, -B, -f, -h, -m, -j, -J options are applicable only in VCS environment.

Last updated: March 2006
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