NPIV LUN or disk level validation
With the Virtual I/O Server (VIOS) version 2.2.4.0 or earlier, partition mobility validation for N_Port ID Virtualization (NPIV) devices are checked only up to the port level. This resulted in the possibility of client failures if the actual disk mapped to the client on the source system were not properly mapped on the destination system. With the VIOS version 2.2.4.0, you can validate up to the disk mapping. To perform disk level validation, both the source and destination VIOS must be at level 2.2.4.0 or later, and the Hardware Management Console (HMC) must be at least at Version 7.4.4.
Disk validation can add a considerable amount of time to partition mobility validation for clients that are using NPIV disks. The amount of time that is required to validate NPIV devices up to the disk level depends on the number of disks that are mapped to a client. For larger configurations, the additional time that is spent in validation might have a noticeable impact on the overall time that is required to migrate the partition. Therefore, it is suggested that you might want to consider performing periodic partition mobility validation with LUN level validation enabled. Also, it would be prudent to plan the validation outside of scheduled maintenance windows and either skip validation, or run validation with LUN level validation disabled when partition mobility operations must be completed in a short period.
- Since disk validation sends additional commands to the SAN, any instability in the SAN might result in validation failures where port level validation might have succeeded.
- Disk mapping validation is done during partition mobility validation, and is not done during migration. The migration phase of a partition mobility operation validates only up to the port level.
- When you are using the HMC graphical user interface, validation is always done for each partition mobility operation. You must keep this in mind before you enable disk level validation, particularly if the client has many disks.
- When the HMC command line interface is used, validation is performed only if the –o flag is set to the character v and migration is done only if the ––o flag is set to the character m. These flags are mutually exclusive.
