Partition mobility overview

Partition mobility is the ability to migrate a logical partition, including its operating system and applications, from one system to another system. Partition migration can be active or inactive. Active partition migration lets you move a running logical partition from one system to another system without shutting down the partition or applications running on the partition. Inactive partition migration lets you move a powered-off logical partition from one system to another system.

The partition migration environment consists of the following parts:

Partition migration environment part	Description
Source system	The system from which you want to move the logical partition.
Destination system	The system to which you want to move the logical partition.
Hardware Management Console (HMC)	The management tool you use to move the logical partition from the source system to the destination system. Partition Mobility requires one of the following HMC configurations: Both the source and destination servers are managed by the same HMC (or redundant HMC pair). In this case, the HMC must be at version 7 release 3.2, or later. The source server is managed by one HMC and the destination server is managed by a different HMC. In this case, both the source HMC and the destination HMC must meet the following requirements: The source HMC and the destination HMC must be connected to the same network so that they can communicate with each other. The source HMC and the destination HMC must be at version 7, release 3.4, or later In order to move a shared memory partition, the source HMC and destination HMC (if available) must be at version 7, release 3.4.2, or later.
Migrating partition	The logical partition that you want to move from the source system to the destination system. If the source system and the destination system have a shared memory pool with at least one paging Virtual I/O Server (VIOS) partition, then the migrating partition can be a shared memory partition.
Source Virtual I/O Server logical partition	At least one Virtual I/O Server logical partition on the source system that provides the migrating partition with storage and networking resources. For active partition migration, this could also be the mover service partition that transfers the partition state information to the destination environment. The VIOS partition that acts as the Mover Service Partition does not need to be the same VIOS partition that provides virtual storage and networking resources to client partitions on the system. If the mobile partition is a shared memory partition, at least one paging VIOS partition on the source system must provide access to a paging space device. The paging VIOS partition could be the same VIOS partition that is the mover service partition. The paging VIOS partition could also be the VIOS partition that provides the mobile partition with virtual SCSI, virtual Ethernet, and virtual fiber channel resources. The source paging VIOS partition provides access to the paging space device for the mobile partition on the source system.
Destination Virtual I/O Server logical partition	At least one Virtual I/O Server logical partition on the destination server that provides the migrating partition with all of its storage and networking resources after the migrating partition is moved. For active partition migration, this could also be the mover service partition that receives the partition state information from the source environment. The VIOS partition that acts as the Mover Service Partition does not need to be the same VIOS partition that provides virtual storage and networking resources to client partitions on the system. If the mobile partition is a shared memory partition, at least one Virtual I/O Server partition on the destination system must provide access to a paging space device. The paging VIOS partition could be the same VIOS partition that is the mover service partition. The paging VIOS partition could also be the VIOS partition that provides the mobile partition with virtual SCSI, virtual Ethernet, and virtual fiber channel resources. The destination paging VIOS partition provides access to the paging space device for the mobile partition on the destination system.
Storage area network	Provides the migrating partition with access to the same storage from both the source and the destination environments. The migrating partition receives its storage resources from a Virtual I/O Server on both the source and destination systems. Both the source and destination Virtual I/O Servers are connected to the storage area network. The same physical storage must be assigned to the source and destination Virtual I/O Servers so that the migrating partition can access the storage from both the source and destination environments.
Local area network (LAN)	Provides the means to transport the partition state information from the source environment to the destination environment. The migrating partition receives its networking resources from a Virtual I/O Server on both the source and destination systems. Both the source and destination Virtual I/O Servers use a shared Ethernet adapter to connect their virtual networks to the LAN on the Virtual I/O servers designated as mover service partitions. This provides the connection necessary to transfer the partition state information from the source environment to the destination environment. In addition, the source and destination network environments must be configured so that the migrating partition can continue to communicate with the necessary clients and servers after it is moved from the source environment to the destination environment.

If your partition migration environment supports Active Memory Sharing, these additional concepts may apply:

Active Memory Sharing partition migration concepts	Description
Shared Memory Partition	When a partition uses shared memory, a VIOS partition with access to a paging space device is required to provide paging space to the shared memory pool. A paging space device is a physical or logical device that is used to hold portions of a shared memory partition’s logical memory that do not reside in the shared memory pool. When the operating system that runs in a shared memory partition attempts to access data, and the data is located on the shared memory partition’s paging space device, the hypervisor sends a request to the Virtual I/O Server to retrieve the data and write it to the shared memory pool so that the operating system can access it. To migrate a shared memory partition, a shared memory pool and supporting VIOS partitions with the required paging space device support must exist on the destination managed system.
Redundant paging VIOS support	When migrating a partition that uses shared memory, you can configure this partition to use dual paging VIOS partitions for redundancy on the destination managed system. When redundancy is successfully configured for the migrating partition, a paging device that can be accessed through both paging VIOS partitions configured to the shared memory pool on the destination system is allocated to the migrating partition. If the primary paging VIOS partition fails, the paging space can be accessed through the secondary paging VIOS partition.

Active Memory Sharing partition migration concepts

Description

Shared Memory Partition

When a partition uses shared memory, a VIOS partition with access to a paging space device is required to provide paging space to the shared memory pool. A paging space device is a physical or logical device that is used to hold portions of a shared memory partition’s logical memory that do not reside in the shared memory pool. When the operating system that runs in a shared memory partition attempts to access data, and the data is located on the shared memory partition’s paging space device, the hypervisor sends a request to the Virtual I/O Server to retrieve the data and write it to the shared memory pool so that the operating system can access it.

To migrate a shared memory partition, a shared memory pool and supporting VIOS partitions with the required paging space device support must exist on the destination managed system.

Redundant paging VIOS support

When migrating a partition that uses shared memory, you can configure this partition to use dual paging VIOS partitions for redundancy on the destination managed system. When redundancy is successfully configured for the migrating partition, a paging device that can be accessed through both paging VIOS partitions configured to the shared memory pool on the destination system is allocated to the migrating partition. If the primary paging VIOS partition fails, the paging space can be accessed through the secondary paging VIOS partition.

Partition migration requires that you properly prepare your source and destination environments. If these environments are not configured properly, the migration can fail. For step-by-step instructions about how to prepare your environments for partition migration, see the Partition Mobility documentation: Live Partition Mobility.