Ubuntu Manpage: /etc/sysconfig/o2cb - Cluster configuration file for the o2cb cluster stack.

NAME

       /etc/sysconfig/o2cb - Cluster configuration file for the o2cb cluster stack.

SYNOPSIS

       The  configuration  file /etc/sysconfig/o2cb stores the active cluster stack, its name and
       the various cluster timeouts for the o2cb cluster stack.

DESCRIPTION

This file can be populated using the o2cb init script. An example of the same is
illustrated in the examples section.

The list of configurable parameters in this file are:

O2CB_STACK
Name of the cluster stack. The possible values are o2cb, pcmk and cman. o2cb is
the default cluster stack of the OCFS2 file system. pcmk (Pacemaker) and cman
(rgmanager) are the two other cluster stacks that are supported by the same file
system.

O2CB_BOOTCLUSTER
Name of the active cluster. While /etc/ocfs2/cluster.conf can hold descriptions of
multiple clusters, only one can be active at any one time. The name of that active
cluster is specified here. The name itself can be up to 16 alphanumeric characters
[0-9A-Za-z] with no special characters.

The remaining configurable parameters (cluster timeouts) are only relevant for the o2cb
cluster stack. These cluster timeouts are used by the o2cb cluster stack to determine
whether a node is dead or alive. The default timeouts are just a guide and may need to be
tweaked depending on the hardware the software is running on.

The various cluster timeouts for the o2cb cluster stack are:

O2CB_HEARTBEAT_THRESHOLD
The disk heartbeat timeout is the number of two second iterations before a node is
considered dead. The exact formula used to convert the timeout in seconds to the
number of iterations is as follows:

O2CB_HEARTBEAT_THRESHOLD = (((timeout in seconds) / 2) + 1)

For example, to specify a 60 sec timeout, set it to 31. For 120 secs, set it to 61.
The default for this timeout is 60 secs (O2CB_HEARTBEAT_THRESHOLD = 31).

While it defaults to 60 secs, multipath users typically set it to 120 secs.

O2CB_IDLE_TIMEOUT_MS
The network idle timeout specifies the time in milliseconds before a network
connection is considered dead. While it defaults to 30000 ms, network bonding users
typically set it to 60000 ms.

O2CB_KEEPALIVE_DELAY_MS
The network keepalive specifies the maximum delay in milliseconds before a
keepalive packet is sent to another node to check whether it is alive or not. It
defaults to 2000 ms.

O2CB_RECONNECT_DELAY_MS
The network reconnect specifies the minimum delay in milliseconds between repeated
connect attempts. It defaults to 2000 ms.

EXAMPLE

       The example below illustrates populating the o2cb  sysconfig  file  using  the  o2cb  init
       script.

       $ service o2cb configure
       Configuring the O2CB driver.

       This will configure the on-boot properties of the O2CB driver.
       The following questions will determine whether the driver is loaded on
       boot.  The current values will be shown in brackets ('[]').  Hitting
       <ENTER> without typing an answer will keep that current value.  Ctrl-C
       will abort.

       Load O2CB driver on boot (y/n) [n]: y
       Cluster stack backing O2CB [o2cb]:
       Cluster to start on boot (Enter "none" to clear) [ocfs2]: webcluster
       Specify heartbeat dead threshold (>=7) [31]: 62
       Specify network idle timeout in ms (>=5000) [30000]: 60000
       Specify network keepalive delay in ms (>=1000) [2000]:
       Specify network reconnect delay in ms (>=2000) [2000]:
       Writing O2CB configuration: OK

       $ cat /etc/sysconfig/o2cb
       #
       # This is a configuration file for automatic startup of the O2CB
       # driver.  It is generated by running /etc/init.d/o2cb configure.
       # On Debian based systems the preferred method is running
       # 'dpkg-reconfigure ocfs2-tools'.
       #

       # O2CB_ENABLED: 'true' means to load the driver on boot.
       O2CB_ENABLED=true

       # O2CB_STACK: The name of the cluster stack backing O2CB.
       O2CB_STACK=o2cb

       # O2CB_BOOTCLUSTER: If not empty, the name of a cluster to start.
       O2CB_BOOTCLUSTER=webcluster

       # O2CB_HEARTBEAT_THRESHOLD: Iterations before a node is considered dead.
       O2CB_HEARTBEAT_THRESHOLD=62

       # O2CB_IDLE_TIMEOUT_MS: Time in ms before a network connection is considered dead.
       O2CB_IDLE_TIMEOUT_MS=60000

       # O2CB_KEEPALIVE_DELAY_MS: Max time in ms before a keepalive packet is sent
       O2CB_KEEPALIVE_DELAY_MS=2000

       # O2CB_RECONNECT_DELAY_MS: Min time in ms between connection attempts
       O2CB_RECONNECT_DELAY_MS=2000

AUTHORS

       Oracle Corporation

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