Upgrading Clusters; Cluster Upgrade Prerequisites; Recognizing Failure Situations; Chapter 8 Upgrading Csm Software - Cisco MDS 9216 Configuration Manual

Upgrading Clusters

Upgrading Clusters

Cluster software upgrades are done concurrently with user I/O operations and selected management
activities.
When software upgrades are in progress, not all nodes in the cluster are operational depending on the
Note
upgrade phase. Consequently, the cache operates in write through mode.
Configuration changes are disallowed from the time the upgrade is started until the upgrade operation
Tip
has terminated successfully. In case of failure, the upgraded and/or failed nodes must be reverted to the
original software version before configuration changes are permitted. If any configuration change is
attempted during this time, an error message is issued to indicate that an upgrade is in progress.

Cluster Upgrade Prerequisites

To prepare a switch for cluster software upgrade, follow these steps.
Wait for all data migration to complete. The time taken for the data migration depends on the size of the
Step 1
VDisks being migrated.
Data migration, once started, cannot be stopped.
Caution
Step 2 Wait for all FlashCopy mappings to complete or stop them. If you choose to stop the FlashCopy
mapping, this will result in the FlashCopy targets going offline. The FlashCopy must be prepared and
started again in order to restart FlashCopy. This procedure results in the FlashCopy point-in-time being
lost.
Stop all remote copy relationships.
Step 3

Recognizing Failure Situations

Cluster software upgrade will fail if one of the following situations apply:
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Cisco MDS 9000 Family SAN Volume Controller Configuration Guide
8-2
Any node configured to be a member of the cluster is not present—in order to upgrade the software
the node must either be deleted from the cluster or must be brought online.
All the nodes configured into the cluster do not currently have the same software level—may happen
as result of a failed back out or a service mode upgrade. This behavior cannot be overridden using
the force option.
The new SVC software image is not compatible with the current switch or the SVC software level.
This behavior cannot be overridden using the force option.
A node has been deleted from the cluster such that any I/O group has only one member—the upgrade
process would result in loss of access to data if this were allowed. The force option can be used to
override this restriction if you do not mind losing access to data during the upgrade.
Chapter 8 Upgrading CSM Software
78-16119-01, Cisco MDS SAN-OS Release 1.3