IBM System p LPM (Live Partition Mobility) Requirements

The requirements for successful migration of active LPARs between Power Systems servers using PowerVM Live Partition Mobility include the following:

1.       Both source and target server must have POWER6 CPUs and both must have PowerVM Enterprise Edition installed. JS22 blades are eligible (but not JS21).

2.       The LPAR to be migrated cannot be a VIO server.

3.       Virtual I/O servers on the two servers must be able to communicate over the network.

4.        Time of Day clocks for VIO servers should be synchronized.

5.       The DVD in the VIO may not be attached to mobile LPAR as virtual optical device.

6.       If using FBO (file backed optical) no virtual optical device can be attached to the mobile LPAR.

7.        A supported AIX, Linux or IBM i version.

8.       LPAR to be moved must be running AIX V5.3 TL 07, AIX V6.1, or RHEL 5 update 1 or later, SUSE (SLES 10) Service pack 1 or later.

9.       If HMC-managed, both servers must be managed by the same HMC until Release 7 Version 3.4 of the HMC code, which introduced the ability to migrate between different HMCs.

10.   In the move preparation phase, the contents of an LPAR's memory must be transmitted over virtual Ethernet (via Virtual I/O Servers) from the source LPAR to the target LPAR. Pages updated after transmission must be transmitted again. Assuming a Gigabit Ethernet can transmit 80 MB/sec and that 256 GB of working memory is in use on the source LPAR, it will take at least 256*1024/80 = 3276.8 seconds or one hour to prepare for the move if only a gigabit of network bandwidth is available. That's assuming source working memory pages are not updated after they are transmitted, which is NOT a good assumption, so actual time will be longer. The Virtual I/O Servers will consume roughly one CPU on the source and one on the target managing the data transmission. (See VIOS Sizing for more information on estimating CPU consumption by a VIO Server.) And unless sufficient network bandwidth is available to accommodate the additional network activity, application network bandwidth and response time will be impacted during the move preparation phase.

11.   Once the move preparation phase is complete, only a few seconds are required to actually move the LPAR.

12.   All I/O must be virtualized in an LPAR to be moved - any dedicated PCI adapters (physical adapter) must be deallocated before the LPAR can be moved. Dedicated IO adapters must be de-allocated before migration.

13.   AIX must boot from LUNs accessible to both virtual I/O servers. Considerations when booting from SAN suggest that AIX dump space be configured on a SCSI hdisk dedicated to the LPAR or on a vSCSI disk which is mapped to an internal SCSI disk dedicated to a virtual I/O server LPAR. AIX dump space must therefore be deallocated (or perhaps reallocated to a LUN) prior to moving the LPAR and (re)allocated to a (different) dedicated SCSI disk after moving the LPAR.

14.   Network switches and routers must support and properly handle gratuitous ARP packets, so that when the network sees the LPAR's IP (and MAC?) addresses jump from one network port to another, the jump will be handled properly.

15.   The source and target VIO servers must have access to the same network (VLAN and subnet) with a SEA (shared ethernet adapter).

16.   The target frame must have enough cores, memory and virtual adapter slots free.

Ref: SG24-7460