Hello -
- The assignment of LUNs can only be from those that are part of the storage partition (HA) and local volumes cannot be created.
This is not completely true - You absolutely CAN create local and HA volumes on the same system, however, a host cannot have volumes that are Both HA and Local. One of the many values of PBHA over Hyperswap is that you can maintain access to local only volumes in the event of link failure, whereas in Hyperswap if you lose access to the other site, you will lose access to the local and HA volumes. Please be aware, there is an existing Idea to allow hosts to exist in multiple partitions that you/your client should consider voting on IBM Aha!
- A preferred site cannot be chosen since in the storage partition configuration the alternate site appears as passive, so the pool when creating the volume must always be the primary one.
You need to use the active management system to create volume for the partition - this is correct. However, you can create local only partitions, dictating the active management system.
- If a LUN is created that does not belong to the Storage Partition, it cannot be assigned to the Host that already belongs to the Storage partition.
This is correct at time of writing.
- If you want to add more wwpn identifiers to a host that is in the storage partition, it is not allowed.
This is a current restriction at time of writing.
- If you try to create a volume in an alternate site that is part of a volume Group, it is not possible because the alternate site is the passive one.
You need to use the active management system to create volumes for a partition. This is core to the design to avoid making you do things in two places (another key value of Policy based management). Please be aware, that a system may have multiple partitions and they do not need to have the same active management system across the set.
I hope this helps. If you or your client have any questions about PBHA and want to get more details or a roadmap, please reach out to your IBM Sales contacts for more information. We also provide playbacks and design feedback with the development team if they want to get involved in the design thinking process.