Dell PowerStore Importing External Storage to PowerStore Guide

Overview of the agentless import process

Before importing the external storage from a source system to a PowerStore cluster, the active path for the host I/O is to the source system. The host or hosts are not automatically added to the PowerStore cluster and must be added manually before setting up the agentless import. During the setup of an agentless import, volumes are created on the PowerStore cluster that match the specified volumes on the source system. However, unlike non-disruptive import, the host applications that access the source system volume or volumes must be shut down manually and the source volumes brought offline.

To start an agentless import, the destination volume must be manually enabled and the host application must be reconfigured to use the destination volume instead of the source volume. The destination volume is read-only until it is enabled. Once the destination volume has been enabled, the host application has to be reconfigured to access the destination volume. Start the import to copy the source volume data to the destination volume. The source system is kept updated through I/O forwarding from the PowerStore cluster. When the import reaches the Ready For Cutover state, you can initiate the cutover. The I/O forwarding from the PowerStore cluster to the source system ends when cutover is initiated.

Review the following processes to gain an understanding of the import procedure:

1. Preconfigure – Set up the network connectivity.
   • The connection between an existing Dell PS Series source system and the PowerStore cluster must be over iSCSI.
   • For Dell PS Series source systems – All the connections between the hosts and source system, and between the hosts and the PowerStore cluster must be over iSCSI.
   • For Dell SC Series, Dell Unity Series, Dell VNX2 Series, Dell XtremIO X1 or XtremIO X2, and NetApp AFF A-Series or Universal (either legacy Dell or third-party) source systems – The connections between the hosts and the source system and between the hosts and the PowerStore cluster must be either all over iSCSI or all over Fibre Channel (FC). See the PowerStore Simple Support Matrix document to determine which protocol to use
     NOTE:When FC connectivity is used between the hosts and the source system, the hosts and the PowerStore cluster, and the source system and the PowerStore cluster, the administrator must set up FC zoning between the hosts, the source system, and the PowerStore cluster. When the connections between the source system and the PowerStore cluster are all over iSCSI, the connections between the hosts and the source system and between the hosts and the PowerStore cluster can be either all over iSCSI or all over FC. However, when the connections between the source system and the PowerStore cluster are all over FC, the connections between the hosts and the source system and between the hosts and the PowerStore cluster must be all over FC.
   • The connection between an existing Dell SC Series, Dell Unity Series, Dell VNX2 Series, or Dell XtremIO X1 or XtremIO X2 source system, or NetApp AFF A-Series or Universal source system and the PowerStore cluster can be over either iSCSI or FC. See the PowerStore Simple Support Matrix document to determine which protocol to use.
   • The connection between an existing Dell PowerMax or VMAX3 source system and the PowerStore cluster must be over FC.
     NOTE: The administrator must set up FC zoning between the source system and the PowerStore cluster.
   • For Dell PowerMax and VMAX3 source systems – All the connections between the hosts and the source system and between the hosts and the PowerStore cluster must be over FC.
     NOTE:The administrator must set up FC zoning between the hosts, the source system, and the PowerStore cluster.
2. Setup import – If they are not already listed, add the source system and the hosts to the PowerStore cluster. Select one or more volumes or consistency groups (CGs), or both, or LUNs, or storage group to be imported. A volume group or storage group cannot be combined with any other volume or volume group. Select to map the hosts that access the storage to be imported. Set the import schedule and assign a protection policy.
   NOTE:For a Universal remote source system, you must add PowerStore with either iSCSI initiators or FC as a host on the source system and map the applicable volumes to it.
3. Start import – A destination volume is created for each selected source volume. Except for the Universal type of remote source systems, a volume group is automatically created for each CG or storage group that is selected for import. When the destination volume is in the Ready To Enable Destination Volume state, shutdown or take off line the host application on the applicable host or hosts that use the source volume. Also, remove the host mapping to the applicable source system volume. Select and enable the destination volume which is in the Ready To Enable Destination Volume state. Reconfigure the host application to use the applicable destination volume. Ensure that the host application can work successfully using the destination volume. Select and Start Copy for the destination volume which is in the Ready to Start Copy state.
   NOTE:It is recommended to remove the host mapping of the source volumes during the enable destination volume process. If the host mapping of the source volumes is not selected for removal by the orchestrator, the mapping should be removed manually. Also, only one agentless import can be processed from the PowerStore cluster at any point in time until the import process reaches the Ready to Start Copy state. A second agentless import will start execution only after the previous import reaches the Copy In Progress state.
   NOTE:Only volumes are discovered for a Universal type remote system. Consistency groups are not discovered. If a consistency group exists on the source system and should also exist on the destination, PowerStore Manager provides options to create it and to add the applicable volumes to it. When a consistency group is created in this manner, a volume group is automatically created in place of the consistency group on PowerStore during import. If you would like to group discovered individual volumes as a volume group when they are imported, PowerStore Manager provides options to create the volume group and to add the applicable volumes to it.
4. Cutover import – Cutover can be performed only when the import processing state appears as Ready For Cutover. In other words, cutover is a final confirmation. You can select to cut over automatically without user intervention.
   NOTE: After cutover of each volume or CG, it is recommended that the mapping of the volume or CG volumes to PowerStore in the source system be removed immediately before performing cutover of the next import session. If removal of the mapping of multiple volumes or CG is performed at once in the source system, it is recommended to leave a gap of at least 10 minutes before mapping the next set of volumes or CG to PowerStore for import. This delay is required for complete clean up of unmapped devices in PowerStore. Otherwise, new imports can fail because mirror service cannot be enabled on the destination volume of the import. In this case, retry the import and, if this error happens consistently, delete the remote system and re-add it to continue further imports.

In addition, the following actions are available during the import procedure:

• Pause import – Pause can be performed when the import processing state appears as Copy In Progress.
  NOTE:The Pause import action on a CG only pauses the member volumes that are in the Copy In Progress state. The CG remains in the In Progress state. Other member volumes that are in other states, such as Queued or In Progress, are not paused and may go to the Ready For Cutover state. The other member volumes can be paused when they reach the Copy In Progress state by using the Pause import action again on the CG. If any of the member volumes are in the Paused state but the overall status of the CG is In Progress, both the Pause and Resume import action options are available for the CG.
• Resume import – Resume can be performed when the import processing state is Paused.
• Cancel import – For volumes, Cancel can be performed only when the import processing state is Queued, Scheduled, Ready To Enable Destination Volume, Ready to Start Copy, Copy In Progress, Paused, Ready for Cutover, or Cancel Required and the host application that is accessing the volume has been shut down. For volume groups, Cancel can be performed only when the import processing state is Queued, Scheduled, In Progress, Paused, Ready for Cutover, Cancel Required, Cancel Failed, and the host application that is accessing the volume has been shut down.
• Enable Destination Volume – Ensure the host application on the applicable host or hosts that use the source volume or volumes have been shut down or taken off line before enabling each destination volume in an import session.
• Start Copy – Start Copy can be performed for each of the destination volumes that are in the Ready to Start Copy state.