Sunday, 14 August 2011

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


1: Review http://cosonok.blogspot.com/2011/08/hp-p4000-multi-site-san-notes.html 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)

2 comments:

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

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

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