Considerations for changing the host protocol

The considerations for changing the host protocol depend on the starting and ending protocols of the baseboard host ports and the HIC ports.

If you use a Mirroring feature or the Data Assurance (DA) feature, you must understand what happens to these features when you change the host port protocol.

Note: The following considerations apply only if you are converting a storage array that has already been in use. These considerations do not apply if you are converting a new storage array that does not yet have hosts and volumes defined.

Converting from FC to iSCSI

Converting from iSCSI to FC

Converting from FC to FC/iSCSI

Mirroring considerations
  • If a storage array used for mirroring currently has only FC ports, and you want to convert some of them to iSCSI, you must determine which ports are used for mirroring.
  • You do not need to convert the ports on the local storage array and the remote storage array to the same protocol as long as both storage arrays have at least one active FC port after the conversion.
  • If you plan to convert the ports that are being used for mirrored relationships, you must deactivate any synchronous or asynchronous mirror relationships before applying the feature pack.

    Synchronous Mirroring is not supported for iSCSI.

  • If you plan to convert the ports that are not being used for mirroring, asynchronous mirroring operations will be unaffected.
  • Before applying the feature pack, you should confirm that all mirror consistency groups are synchronized. After applying the feature pack, you should test the communication between the local storage array and the remote storage array.
Data Assurance considerations
  • The Data Assurance (DA) feature is not supported for iSCSI.

    To ensure that data access remains uninterrupted, you might need to remap or remove DA volumes from host clusters before applying the feature pack.

    If you have... You must...

    DA volumes in the default cluster

    Remap all the DA volumes in the default cluster.
    • If you do not want to share DA volumes between hosts, follow these steps:
      1. Create a host partition for each set of FC host ports (unless this has already been done).
      2. Remap the DA volumes to the appropriate host ports.
    • If you want to share DA volumes between hosts, follow these steps:
      1. Create a host partition for each set of FC host ports (unless this has already been done).
      2. Create a host cluster that includes the appropriate host ports.
      3. Remap the DA volumes to the new host cluster.
        Note: This approach eliminates volume access to any volumes that remain in the default cluster.

    DA volumes in a host cluster that contains FC-only hosts, and you want to add iSCSI-only hosts

    Remove any DA volumes belonging to the cluster, using one of these options.

    Note: DA volumes cannot be shared in this scenario.
    • If you do not want to share DA volumes between hosts, remap all DA volumes to individual FC hosts within the cluster.
    • Segregate the iSCSI-only hosts into their own host cluster, and keep the FC host cluster as is (with shared DA volumes).
    • Add an FC HBA to the iSCSI-only hosts to allow for sharing of both DA and non-DA volumes.

    DA volumes in a host cluster that contains FC-only hosts, or DA volumes that are mapped to an individual FC host partition

    No action is needed before applying the feature pack. DA volumes will remain mapped to their respective FC host.

    No partitions defined

    No action is needed before applying the feature pack because no volumes are currently mapped. After converting the host protocol, follow the proper procedure to create host partitions and, if desired, host clusters.

Converting from iSCSI to FC/iSCSI

  • If you plan to convert a port that is being used for mirroring, you must move the mirroring relationships to a port that will remain iSCSI after the conversion.

    Otherwise, the communication link might be down after the conversion because of a protocol mismatch between the new FC port on the local array and the existing iSCSI port on the remote array.

  • If you plan to convert the ports that are not being used for mirroring, asynchronous mirroring operations will be unaffected.

    Before applying the feature pack, you should confirm that all mirror consistency groups are synchronized. After applying the feature pack, you should test the communication between the local storage array and the remote storage array.

Converting from FC/iSCSI to FC

Converting from FC/iSCSI to iSCSI

Same host protocol and mirroring operations

Mirroring operations are not affected if the host ports being used for mirroring keep the same protocol after you apply the feature pack.

Even so, before applying the feature pack, you should confirm that all mirror consistency groups are synchronized.

After applying the feature pack, you should test the communication between the local storage array and the remote storage array. Refer to the online help for SANtricity System Manager if you have questions on how to do this.