Dell PowerStore Importing External Storage to PowerStore Guide

General block-based import restrictions

The following restrictions apply to importing block-based external storage to PowerStore:

• At any given time a maximum of 6 source systems is supported.
• (For non-disruptive import) A maximum of 64 hosts is supported. The applicable host plugin for import must be installed on the host.
• (For agentless import) See the PowerStore Simple Support Matrix for the maximum number of hosts that are supported.
• A maximum of 8 parallel import sessions is supported, but they all start sequentially. That is, imports start one by one but, once they reach Copy-In-Progress, the next one is taken for processing.
• (For non-disruptive import) A maximum of 16 volumes in a consistency group (CG) is supported.
  NOTE:When a CG has 16 members, a maximum of 8 members is imported in parallel, but they all start sequentially. That is, imports start one by one but, once they reach Copy-In-Progress, the next one is taken for processing. Once any one of them reaches Ready-For-Cutover, the next member is imported in parallel. Once all the members reach Ready-For-Cutover, the CG is Ready-For-Cutover.
• (For agentless import) A maximum of 75 volumes in a consistency group (CG) is supported.
  NOTE:When a CG has 75 members, a maximum of 8 members is imported in parallel, but they all start sequentially. That is, imports start one by one but, once they reach Copy-In-Progress, the next one is taken for processing. Once any one of them reaches Ready-For-Cutover, the next member is imported in parallel. Once all the members reach Ready-For-Cutover, the CG is Ready-For-Cutover.
• A CG that has volumes that are mapped to hosts running different types of operating systems cannot be imported. For example, a CG having volumes from a Linux host and Windows host cannot be imported.
• NVMe host mapping on PowerStore is not supported for importing a volume or CG.
• A maximum of 16 import sessions is supported in the Ready-For-Cutover state. Sometimes when several dozen import operations are run back-to-back, intermittent failures of alternate import sessions may occur. If this occurs, do the following:
  1. Remove the remote (source) system and then add it again.
  2. Run fewer set of imports (16 or less) at a time. It is recommended to start all these import sessions with automatic cutover turned off.
  3. Once all imports have reached the Ready-For-Cutover state, do a manual cutover.
  4. After one set of imports is completed, run the next set of imports after a delay of 10 minutes. This delay allows enough time for the system to cleanup any connections to the source system.
• You can import only an active volume or LUN. Snapshots are not imported.
• It is not recommended to change a host cluster configuration once the volume is selected for import.
• All the target port IP addresses returned by the PowerStore's iSCSI target portal should be reachable from the host where import is planned.
• Replication relationships are not imported.
• SAN boot disks are not supported.
• IPv6 is not supported.
• Veritas Volume Manager (VxVM) is not supported.
• (For non-disruptive import) Only implicit ALUA mode is supported on source systems.
• The following configuration changes are not supported on the source system during import:
  • Firmware or Operating Environment upgrade
  • System re-configuration, including network configuration and restart of node or members
• When any configuration changes, such as moving a volume between hosts or re-sizing the source system volume capacity, are made to the source or a host system after they have been added to PowerStore, all the affected or involved systems must be refreshed from PowerStore Manager.
• Only an iSCSI connection is supported between the following source systems and the PowerStore cluster:
  • Dell EqualLogic PS
  • (For agentless import) NetApp AFF and A Series
  Either an iSCSI connections or Fibre Channel (FC) connection is supported between a Dell Compellent SC or Unity, or Dell VNX2, or XtremIO X1 or XtremIO X2 source system and the PowerStore cluster. However, the connection between the Dell Compellent SC or Unity, or Dell VNX2, or XtremIO X1 or XtremIO X2 source system and the PowerStore cluster, and the connections between the hosts and the Dell Compellent SC or Unity, or Dell VNX2, or XtremIO X1 or XtremIO X2 source system and between the hosts and the PowerStore cluster must be either all over iSCSI or all over FC. (For agentless import) Only a FC connection is supported between a Dell PowerMax or VMAX 3 source system and the PowerStore cluster.
• (For non-disruptive import) SCSI-2 clusters are not supported. Only SCSI-3 persistent reservation (PR) clusters are supported.
• Heterogeneous host cluster is not supported.
• Configuration changes must not be made during import, such as resizing a volume during import or adding or removing a host node in a cluster configuration, on either the source system or PowerStore. The following configuration changes are allowed but not supported on either the source system or PowerStore during import for consistency groups:
  • Removing members from consistency group
  • Restoring
  • Cloning
  • Snapshot
  • Consistency group migration
  • Creating replication
  • Refreshing volume
  Such operations should be done before starting import.
• Snapshot restore on a volume under import is not supported.
• Only 512b-sector sized devices are supported from the following systems, 4k-sector devices are not supported from these systems:
  • Dell EqualLogic PS
  • Dell Compellent SC
  • Dell Unity
  • Dell VNX2
• Both 512b-sector and 4k-sector resources are supported from XtremIO systems.
• iSCSI hardware initiators are not supported.
• Running in iSCSI Data Center Bridging (DCB) configurations is not supported for Dell EqualLogic PS series and Dell Compellent SC series.
• Do not delete then add the same VNX2 remote system again in a very short interval (few seconds). The add operation may fail because the software cache on the VNX2 may not have completed being updated. Wait at least five minutes between these operations for the same VNX2 remote system.