Source and destination Virtual I/O Server logical partitions in a partition mobility environment

Partition mobility that is managed by a Hardware Management Console (HMC) requires at least one Virtual I/O Server (VIOS) logical partition on the source server and at least one VIOS logical partition on the destination server.

When the VIOS is at Version 2.2.3.0, or later, if any VIOS command fails for any reason during the migration operation, additional information or specific detail about the failure is displayed in an error message with the following format:

VIOS_DETAILED_ERROR
actual error message 1
actual error message 2
......................
......................
End Detailed Message.

The error message looks similar to this example:

VIOS_DETAILED_ERROR
Client Target WWPNs: 50050763080801ae 500507630808c1ae 50050763083341ae
There are no FC adapters
Returning from npiv_dest_adapter rc=83
End Detailed Message.

Server partition

The mobile partition must receive storage and networking resources from the following sources:

At least one VIOS logical partition on the source server.
At least one VIOS logical partition on the destination server.

The VIOS logical partitions provide the mobile partition with access to the same storage from both the source and destination servers.

The mobile partition can access its physical storage through redundant VIOS logical partitions, a VIOS logical partition with redundant physical adapters, or both. In most cases, you must maintain the redundancy configuration of the VIOS logical partitions on the destination system. However, in some situations, you can migrate a logical partition to a destination system with less redundancy.

Where possible, partition mobility preserves the following configuration attributes:

Slot IDs of the virtual server adapters
User-defined names of virtual target devices
User-defined adapter IDs of the virtual server adapters

Mover service partition

For active partition mobility, the following logical partitions must be designated as mover service partitions (MSPs):

At least one VIOS logical partition on the source server.
At least one VIOS logical partition on the destination server

A mover service partition is a VIOS logical partition with the following characteristics:

The MSP attribute indicates that the VIOS logical partition can support active partition migration.
Both VIOS partitions must be at version 1.5 or later.

The source and destination MSPs communicate with each other over the network. On both the source and destination servers, the Virtual Asynchronous Services Interface (VASI) device provides communication between the MSP and the hypervisor. These connections facilitate active partition mobility as follows:

On the source server, the MSP extracts the logical partition state information of the mobile partition from the hypervisor.
The MSP on the source server sends the logical partition state information to the MSP on the destination server.
On the destination server, the MSP installs the logical partition state information to the hypervisor.

When the VIOS is at version 2.2.5.0, and the firmware is at level FW860, or later, and when multiple MSPs are available, redundant MSPs are selected by default for partition mobility operations. Redundant MSPs are supported only for active partition mobility operations. You cannot use redundant MSPs for migrating suspended partitions. Redundancy of MSPs provides better reliability of partition mobility operations during a VIOS failure, some HMC failures, or network failures.

Paging VIOS partition

A VIOS logical partition that is assigned to the shared memory pool (hereafter referred to as a paging VIOS partition) provides access to the paging space devices for the logical partitions that use shared memory.

You are not required to maintain the same number of paging VIOS partitions for the mobile partition from the source server to the destination server. For example, a mobile partition that uses redundant paging VIOS partitions on the source server can migrate to a destination server with only one paging VIOS partition assigned to the shared memory pool. Similarly, a mobile partition that uses a single paging VIOS partition on the source server can use redundant paging VIOS partitions on the destination server, if two paging VIOS partitions are assigned to the shared memory pool on the destination server. The following table describes these redundancy options in more detail.

When you validate the configuration for active partition mobility, the HMC checks that the paging VIOS partitions on the destination system have access to a paging space device that meets the size requirements of the mobile partition as well as the redundancy preferences that you specify. The HMC selects and assigns paging space devices to the mobile partition on the destination system by using the same process as used during partition activation. For details, see Paging space devices on systems that are managed by an HMC.

Table 1. Redundancy options for the paging VIOS partitions that are assigned to the mobile partition
Number of paging VIOS partitions that are used by the mobile partition on the source server	Number of paging VIOS partitions that are assigned to the shared memory pool on the destination server
1 The mobile partition uses a single paging VIOS partition to access its paging space device on the source system.	1 Because there is only one paging VIOS partition that is assigned to the shared memory pool on the destination system, the mobile partition must continue to use a single paging VIOS partition to access a paging space device on the destination system. To successfully migrate the mobile partition in this situation, you can perform one of the following actions: Do not specify a redundancy preference. By default, the HMC attempts to maintain the current redundancy configuration on the destination system. In this case, the mobile partition continues to use a single paging VIOS partition to access a paging space device on the destination system. Specify that the mobile partition does not use redundant paging VIOS partitions. The mobile partition continues to use a single paging VIOS partition to access a paging space device on the destination system. Specify that the mobile partition uses redundant paging VIOS partitions, if possible. Use this option if you do not know whether the mobile partition can use redundant paging VIOS partitions on the destination system. The HMC examines the destination system to determine whether it is configured to support redundant paging VIOS partitions. In this case, the HMC finds that the mobile partition cannot use redundant paging VIOS partitions because only one paging VIOS partition is assigned to the shared memory pool on the destination server. Instead, the mobile partition continues to use a single paging VIOS partition to access a paging space device on the destination system.
1 The mobile partition uses a single paging VIOS partition to access its paging space device on the source system.	2 To successfully migrate the mobile partition in this situation, you can perform one of the following actions: Do not specify a redundancy preference. By default, the HMC attempts to maintain the current redundancy configuration on the destination system. In this case, the mobile partition continues to use a single paging VIOS partition to access a paging space device on the destination system. Specify that the mobile partition does not use redundant paging VIOS partitions. The mobile partition continues to use a single paging VIOS partition to access a paging space device on the destination system. Specify that the mobile partition uses redundant paging VIOS partitions, if possible. Use this option if you want the mobile partition to use redundant paging VIOS partitions on the destination system or if you do not know whether the mobile partition can use redundant paging VIOS partitions on the destination system. The HMC examines the destination system to determine whether it is configured to support redundant paging VIOS partitions. In this case, the HMC finds that the mobile partition can use redundant paging VIOS partitions because two paging VIOS partitions are assigned to the shared memory pool on the destination server. The mobile partition uses redundant paging VIOS partitions to access a paging space device on the destination system.
2 The mobile partition uses redundant paging VIOS partitions to access its paging space device on the source system.	1 Because only one paging VIOS partition is assigned to the shared memory pool on the destination server, the mobile partition cannot continue to use redundant paging VIOS partitions to access a paging space device on the destination system. Instead, it must use a single paging VIOS partition to access a paging space device. To successfully migrate the mobile partition in this situation, you can perform one of the following actions: Specify that the mobile partition does not use redundant paging VIOS partitions. The mobile partition uses a single paging VIOS partition to access a paging space device on the destination system. Specify that the mobile partition uses redundant paging VIOS partitions, if possible. Use this option if you do not know whether the mobile partition can use redundant paging VIOS partitions on the destination system. The HMC examines the destination system to determine whether it is configured to support redundant paging VIOS partitions. In this case, the HMC finds that the mobile partition cannot use redundant paging VIOS partitions because only one paging VIOS partition is assigned to the shared memory pool on the destination server. Instead, the mobile partition uses a single paging VIOS partition to access a paging space device on the destination system.
2 The mobile partition uses redundant paging VIOS partitions to access its paging space device on the source system.	2 To successfully migrate the mobile partition in this situation, you can perform one of the following actions: Do not specify a redundancy preference. By default, the HMC attempts to maintain the current redundancy configuration on the destination system. In this case, the mobile partition continues to use redundant paging VIOS partitions to access a paging space device on the destination system. Specify that the mobile partition does not use redundant paging VIOS partitions. The mobile partition uses a single paging VIOS partition to access a paging space device on the destination system. Specify that the mobile partition uses redundant paging VIOS partitions, if possible. Use this option if you want the mobile partition to use redundant paging VIOS partitions on the destination system or if you do not know whether the mobile partition can use redundant paging VIOS partitions on the destination system. The HMC examines the destination system to determine whether it is configured to support redundant paging VIOS partitions. In this case, the HMC finds that the mobile partition can use redundant paging VIOS partitions because two paging VIOS partitions are assigned to the shared memory pool on the destination server. The mobile partition continues to use redundant paging VIOS partitions to access a paging space device on the destination system.

Last updated: Tue, March 12, 2019