Tips for migrating IBM PowerHA systemmirror clusters to IBM POWER7 servers

The purpose of the text is to provide a step-by-step guide to migrating an existing IBM HACMP (PowerHA) cluster from a POWER6 processor-based server to a new server based on the POWER7 processor. This article is based on a real customer scenario. Although your environment and requirements may not match what is given here, a similar approach can be applied in most other cases.

The customer purchased two new IBM Power systems™795 (9119-FHB) servers based on POWER7 processor technology. They need to migrate existing HACMP clusters from old POWER6 hardware to new systems. In addition to server migrations, they need to upgrade HACMP (because their current version will soon stop providing support). As part of the POWER7 migration, we think we can upgrade the cluster appropriately because the cluster needs to be offline anyway during the migration.

The customer's http://www.aliyun.com/zixun/aggregation/13999.html "> workload is dispersed across two existing IBM power 595 (9119-FHA) systems based on POWER6 processor technology. The existing cluster installs the HACMP v5.4. It is a cluster of two nodes, with one cluster node on each power 595 server. The LPAR and the cluster have been built for many years. Therefore, as part of the migration process, you need to change or upgrade the following components:

New POWER7 logical partition (LPAR) with new 8 GB Fibre Channel (FC) and 1 GB Ethernet adapters. The old POWER6 LPAR and power 595 servers will retire together. After introducing new disk storage, we need to migrate the cluster-shared volume group disks from the IBM System storage®ds8300 disk to the Hitachi Data Bae (HDS) virtual service processor (VSP) disk device. subsystem device drivers (subsystem Device Driver, SDD) and associated vpath devices need to be removed because there is no longer an IBM storage device on the new LPAR. To support the new HDS disk device, we need to install the HDS Object Data Manager (ODM) file set (and configure the new HDS VSP hdisks device). The volume groups that are shared in the cluster are converted from standard mode to enhanced concurrency mode. A new network switch was introduced. The 1GB Ethernet adapter in the POWER7 LPAR will be connected to the new switch. IBM aix®5.3* (from TL8) is updated to TL12. HACMP 5.4 Migrated to PowerHA 6.1.

* Note: AIX 5.3 is no longer supported. When planning to perform a POWER7 migration (September 2011), they want to still use AIX 5.3, given that their application software has not yet been validated for operation on AIX 7.1 (or 6.1). They plan to upgrade the cluster to AIX 7.1 this year (2013).

Migration overview

Before we started the migration, we generated a (very) general List of the steps needed to achieve our goals. The overall migration steps are as follows:

Restore the LPAR (mksysb recover = yes) from devices via the Network Setup Manager (receptacle installation Management, NIM) on the new POWER7 Lpar. Migrate the shared and unshared disk configuration from IBM to the HDS disk. Import a unshared volume group. Import a shared volume group. Perform HACMP discovery to find new (HDS) Hdisks devices instead of Vpath (SDD). Synchronize/validate the cluster. Start the Cluster service. Reconfigure the disk heartbeat to use Hdisks instead of Vpath. Synchronize/validate the cluster. Enable shared volume groups for fast disk takeover (enhanced concurrency mode). Synchronize/validate the cluster. Stop cluster services on two nodes. Start the Cluster service on two nodes. Verify that the shared disk group is connected in enhanced concurrency mode. Stop cluster services on two nodes. Upgrade (migrate) HACMP 5.4 on two nodes to PowerHA 6.1 SP6. Restart the two nodes. Start the Cluster service. Synchronize/validate the cluster. Perform a cluster failover test. Make sure the migration is complete.

At the end of the migration, the cluster nodes are located on a POWER7 processor-based system, that is, each node is on a power 795 server. Each node will run PowerHA 6.1, leveraging the HDS disk device for all AIX volume groups.