Error Message

Setting peerinact too low can trigger GAB to panic the system. If there are known network delays in the environment, then peerinact should be set higher than the longest typical delay. 

Here are two example messages from a Linux system where a network disconnect caused a GAB panic.

Messages like this will lead up to the panic in the system log.

VCS WARNING V-16-1-10485 Excessive delay between successive calls to GAB heartbeat (17 seconds)

Typically, an error similar to this is found in the core dump if one was generated.

Kernel panic - not syncing: GAB: Port f halting system due to network failure at [14:2277]

The default peerinact value may not be suitable for all environments, especially virtualized setups where latency can be higher than a physical environment. Adjusting this parameter is necessary to accommodate specific needs and ensure optimal performance.

Increase peerinact to a value that is greater than the longest expected network delay in the environment. The default value is 1600, but for virtualized environments we recommend starting with a value of 3200. This value is in hundredths of a second or centiseconds. The value 3200 is 32 seconds.

To persistently set the value of peerinact:

1. Modify /etc/llttab on each node in the cluster.
# vi /etc/llttab

2. Add the following line at the end of llttab . Ensure that this value is consistent across all nodes in the cluster.
set-timer peerinact:3200
Note:
This configuration will take effect each time the Low Latency Transport (LLT) starts. If this change is made in a running cluster, then it will be applied at the next reboot.

If a reboot is undesireable, this value can be updated dynamically using the "lltconfig" command without rebooting.  This change will take effect immediately, but the changes will not persist after rebooting. Execute the following command on all cluster nodes to update the running LLT configuration to the same value set in /etc/llttab.
# lltconfig -T peerinact:3200

Check the current running LLT configuration for peerinact, use the command below. Ensure that the displayed value matches the desired peerinact setting.

# lltconfig -T query | grep peerinact