To enable concurrent maintenance, configure the system nodes in pairs. If one system node
is being serviced, the other node can keep the network operational.
With concurrent maintenance, the hardware on one
system node can be serviced
or replaced while the network and host systems are doing productive
work.
Attention: Do not remove the power from both system nodes unless the procedures
instruct you to do so.
Verify that concurrent maintenance is enabled before you shut down a node that is part
of a system or when you delete the node from a system. To do so, complete the following checks.
- Confirm that no volumes have dependencies on the node by completing these steps:
- In the management GUI, select .
- On the System -- Overview page, use the directional arrow near the
enclosure that contains the node canister to open the Enclosure Details page.
- Under Rear View of the system, right click the canister and select
Dependent Volumes from the Actions menu you display
all volumes that become unavailable to hosts if the canister is powered off. You can also use the
node parameter with the lsdependentvdisks CLI command to view dependent volumes.
If dependent volumes exist, determine whether the volumes are
being used. If the volumes are being used, either restore the redundant configuration or
suspend the host application. If a dependent quorum disk is reported, repair the access to
the quorum disk or modify the quorum disk configuration.
- Ensure that the host multipathing device drivers can fail over to the partner node.
Some host multipathing device drivers take a while to update after changes are
made on the fabric. Do not shut down a node or delete the node from a cluster if the
partner node in the I/O group to which the node belongs has not been online for more than 30
minutes.
If possible, check the status of the host multipathing device drivers before you
shut down a node to ensure that the device drivers can fail over to the partner node.
When you delete a node from the clustered system, retain the node information that is described
in Deleting a node from a clustered system by using the management GUI. This information helps you
avoid data corruption when you add the node back to the system. The topic describes how to ensure
that the multipathing device driver does not rediscover any paths that are manually removed. Other
considerations about dependent volumes are also provided.
For more information about working with dependent volumes, see the following topics: