Sunday, 14 August 2011

Converting an Existing HP P4000 Storage Cluster into a Multi-Site Cluster

1: Review to check all prerequisites are in place and networking best practices are being followed

Note: The lab demo used here to demonstrate the process, is configured as one Cluster with two Storage Systems, a Virtual Manager, one Server object connected to 2 volumes, and there are no Sites configured.

2: Add the secondary site Storage Systems to the management group as standalone nodes

Example: The image below shows the management group with the two standalone Storage Systems (VSA03 and VSA04) added

3: From 'Getting Started' choose option 2 – 'Management Groups, Clusters, and Volumes Wizard'

4: Choose a Management Group -> select 'Existing Management Group'

and choose the 'Existing Management Group' to be changed

5: Create a Cluster -> select the option 'Existing Cluster' → 'Convert a Standard Cluster to a Multi-Site Cluster'

- and choose the 'Existing Cluster' to be changed -

6: Set up Sites to be Used in Your Multi-Site Cluster → Configure as desired

Example: The image below shows SITEA and SITEB with 2 Storage Systems each (VSA01 and VSA02 in SITEA, VSA03 and VSA04 in SITEB)

7: Assign Virtual IPs and Subnet Masks → Configure as desired

Example: The image below shows the one Virtual IP being used by this Multi-Site Cluster, in different scenarios more Virtual IPs may be used

8: Create Volume → Tick 'Skip Volume Creation' and Finish

Wait a bit and the process of converting to Multi-Site Cluster is nearly complete!

9: (Final step) Right-click the existing Cluster → choose 'Edit Cluster' → click on 'Add Systems...' and add the standalone Storage Systems into the Multi-Site Cluster

Adding Storage Systems to the cluster will cause volumes to restripe but will remain available whilst this is in process.

10: (Optional recommended step) Create a 3rd site object (can be logical) and add a Failover Manager to maintain quorum in the event of a site failure.

Note: in this example of 2 storage systems per site (4 storage systems,) resilience is as below:

Resilient to a system failure in one site
Network-RAID 10, Network-RAID 10+1, Network-RAID 10+2
Resilient to one system failure in each site (two systems)
Network-RAID 10+1, Network RAID 10+2
Resilient to a site failure (two systems)
Network-RAID 10, Network-RAID 10+1, Network-RAID 10+2
Resilient to 3 systems failing
Network-RAID 10+2 (the cluster will lose quorum when 3 nodes are down)


  1. Can this conversion be done without impacting existing production volumes on the primary site?

    1. Yes absolutely. You might want to confirm your environment is healthy and supported for multi-site with HP support first. Cheers!