Qlogic Online Data Migration Using the iSR6200 in Cluster Configurations (ISR651405-00 A, December 2011)

2 – Online Data Migration Methods
ISR651405-00 A 3
2.1
Method 1—Generic Method (Cluster Downtime During Insertion)
Use this method to insert the iSR6200 in the data path of the cluster node in offline mode. You must
bring down cluster nodes during the insertion process. You must also present the source LUNs from the
iSR6200—instead of directly zoning source array ports—and then bring back online the cluster nodes.
Cluster applications can start using shared LUNs as they were doing before the shared LUNs were directly
exposed from the source storage. For details on how to present LUNs to cluster nodes, refer to the Data
Migration Service for iSR6200 User’s Guide.
2.2
Method 2—Online Migration with Zero Downtime
The process for online insertion of the iSR6200 in a cluster data path is exactly as documented in
Appendix A of the Data Migration Service for iSR6200 User’s Guide. The router insertion occurs
transparently without any downtime. However, router insertion requires that you configure specific settings
for the host entity created on the array when you register the router’s Fibre Channel world wide port
numbers (WWPNs) in the array management software. For the method supported during the insertion
process, see Table 3-1 and Table 3-2.
2.3
Method 3—Online Migration with Minimal Downtime
Array-specific multipath (multipath device-specific module) software determines the type of reservation
used for shared cluster resources. For example, the HP StorageWorks XP12000 array uses a SCSI3
reservation (persistent reservation) policy. When the resource is brought offline, the reservation is
released. QLogic recommends that you insert the router after bringing the resource offline because this
requires only a minimal downtime. In addition, it ensures that the router paths are used for SCSI3
(persistent) reservation when resources are brought back online.
Follow these steps to insert the router with this method:
1. Bring down the cluster resource as follows:
a. Bring offline the disk resources associated with the LUNs to be migrated.
b. Ensure that the disks are not being accessed by any application.
2. Replace the direct paths with router paths as follows:
a. Remove all direct paths presented to the host by zoning out the array controller ports from the host
ports. Ensure that you remove paths from both fabrics.
b. Insert the router paths by zoning the router’s presented target WWPNs with the host ports. Ensure
that you zone target presentations from both fabrics.
c. Verify that the storage array is presenting LUNs to all router Fibre Channel WWPNs.
3. Bring the cluster resource online as follows:
a. Using an adapter management utility such as QLogic’s unified adapter management utilities,
QConvergeConsole GUI or CLI, ensure that the host sees only router paths and that no direct paths
are available.
b. Bring the disk resource online.
c. Verify that the cluster application becomes available and can use the cluster resource.