Novell BUSINESS CONTINUITY CLUSTERING FOR NETWARE 1.1 - ADMINISTRATION, Руководство пользователя, Страница: 50 / 98

50 Novell Business Continuity Clustering 1.1 for NetWare Administration Guide
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2.7.1 SAN-based Mirroring Failure Types and Responses
SAN-based mirroring failure types and responses are described in the following sections:
Š
“Primary Cluster Fails but Primary SAN Does Not” on page 50
Š “Primary Cluster and Primary SAN Both Fail” on page 50
Š
“Secondary Cluster Fails but Secondary SAN Does Not” on page 50
Š “Secondary Cluster and Secondary SAN Both Fail” on page 50
Š
“Primary SAN Fails but Primary Cluster Does Not” on page 51
Š “Secondary SAN Fails but Secondary Cluster Does Not” on page 51
Š
“Intersite SAN Connectivity Is Lost” on page 51
Š “Intersite LAN Connectivity Is Lost” on page 51
Primary Cluster Fails but Primary SAN Does Not
This type of failure can be temporary (transient) or long-term. There should be an initial response
and then a long-term response based on whether the failure is transient or long-term. The initial
response is to restore the cluster to normal operations. The long-term response is total recovery from
the failure.
Promote the secondary LUN to primary. Cluster resources load (and become primary on the second
cluster). If the former primary SAN has not been demoted to secondary, you might need to demote it
manually. The former primary SAN must be demoted to secondary before bringing cluster servers
back up. Consult your SAN hardware documentation for instructions on demoting and promoting
SANs. You can use the
cluster resetresources
console command to change resource
states to offline and secondary. See the cluster resetresources command.
Prior to bringing up the cluster servers, the administrator must ensure that the SAN is in a state in
which the cluster resources cannot come online and cause a divergence in data. Divergence in data
occurs when connectivity between SANs has been lost and both clusters assert that they have
ownership of their respective disks.
Primary Cluster and Primary SAN Both Fail
Bring the primary SAN back up and follow your SAN vendor’s instructions to remirror and, if
necessary, promote the former primary SAN back to primary. Then bring up the former primary
cluster servers and fail back the cluster resources.
Secondary Cluster Fails but Secondary SAN Does Not
No additional response is necessary for this failure other than recovering the secondary cluster.
When you bring the secondary cluster back up, the LUNs will still be in a secondary state to the
primary SAN.
Secondary Cluster and Secondary SAN Both Fail
Bring the secondary SAN back up and follow your SAN vendor's instructions to remirror. When you
bring the secondary cluster back up, the LUNs will still be in a secondary state to the primary SAN.