setcontrolledhandover Command

Enables or disables controlled handover.

Syntax

setcontrolledhandover state|list

where state is either TRUE, or FALSE.

Description

This hardware command enables or disables the controlled handover feature. The TRUE option enables and the FALSE option disables the action. The list option provides a listing of the Subnet Manager settings in respect to priority, controlled handover, and subnet prefix.

The InfiniBand specification identifies two parameters used to negotiate a master Subnet Manager - the Subnet Manager priority and the port GUID. Should two or more Subnet Managers have the same highest configured priority, the Subnet Manager with the lowest GUID becomes the master Subnet Manager.

If an un-controlled or automatic handover state exists, when the primary-and-master Subnet Manager fails, the secondary-and-standby Subnet Manager takes on the role of the new master Subnet Manager. During this time, traffic is temporarily suspended as the secondary-and-master Subnet Manager discovers and sets up the InfiniBand fabric.

If the primary Subnet Manager is able to recover from the failure, reboot, and reinitialize itself, it identifies itself as the intended master Subnet Manager. Again, traffic is temporarily suspended as the primary-and-master Subnet Manager re-discovers and sets up the InfiniBand fabric. The secondary Subnet Manager returns to the standby status.

If controlled handover is enabled, then some priority values become reserved. The Subnet Managers dynamically adjust their respective priorities to avoid the dual handover situation. A secondary Subnet Manager that became a master Subnet Manager due to a handover raises its priority to a reserved value and retains its master Subnet Manager status. Regardless if the primary Subnet Manager comes back online, the second handover does not occur.

The user-configured priorities of the Subnet Managers are retained, only during a handover are reserved priorities used.

The result of this scheme is that the user-configured priority is respected during system boot, but dual handover does not occur because the primary Subnet Manager loses its master Subnet Manager status (secondary Subnet Manager priority changes to reserve).

The setcontrolledhandover command is available from the /SYS/Fabric_Mgmt Linux shell target of the Oracle ILOM CLI interface.

Example

This example – shows how to enable a controlled handover of Subnet Managers with the setcontrolledhandover command.

FabMan@switch_name->setcontrolledhandover TRUE
Current SM settings:
smpriority 5
controlled_handover TRUE
subnet_prefix 0xabbababe
M_Key None
FabMan@switch_name->

Related Information

• enablesm Command

• setsmpriority Command

• setsubnetprefix Command

• Linux Shells for Hardware Commands