Dell PowerStore Importing External Storage to PowerStore Guide

Overview of the file-based import process

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

1. Prepare the source VDM for an import – Create a source import network interface.
   NOTE:The interface must be named nas_migration_<interface_name>. Clients are connected to the source VDM either through the NFSv3 or SMB1, SMB2, or SMB3 file sharing protocol.
2. Add the remote system (to establish the import connection) – Establish a file import interface connection to the source VNX2 (Control Station management interface) from PowerStore over SSH. The system is validated, source VDMs are discovered (the configuration of file systems, network interfaces, and such are retrieved), and pre-checks identify the import capability for each VDM on the source system.
   NOTE:The procedure can be repeated on demand for an existing connection.
3. Create a file import session – Specify all the options for the import.
   NOTE:The user settings and the source VDM are validated. If an import session is scheduled to start at a later time, the Import State is shown as Scheduled. However, if two active import sessions (which is the maximum for active import sessions) are running, any new import sessions that are set to start are shown with an Import State of Queued. A maximum of ten import sessions can be scheduled or queued, however, only a maximum of eight import sessions can be scheduled or queued while two import sessions are active.
4. Start the file import session.
   NOTE:The basic configuration of the source VDM must not change since an import session is created.
   1. The import session begins – Destination NAS server, destination file mobility network and destination file systems are created. In the case of an NFS import, unexported file systems are exported.
   2. Initial (baseline) data copy is initiated. Stable data and directory structure is pulled to the destination.
   3. Import of the configuration from the source VDM to the destination NAS server occurs. The configuration includes:
      • Production network interfaces
      • Static routes
      • DNS
      • SMB server
      • SMB shares
      • NFS server
      • NFS exports
      • NIS
      • LDAP
      • Local files
      • Effective naming service
      • Quotas
      NOTE:The session state is shown as Ready For Cutover when the import of the configuration completes. If the file system on the destination system is low on space (reaches 95% of capacity) during import, import of the source file system will fail. In this case you can either ensure that enough space is available and run Resume or Cancel the import session.
5. Cut over the import session – Production interfaces are disabled on the source side and enabled on the destination side.
   NOTE:For SMB import, the Active Directory configuration is imported and the switch over is disruptive. For NFS import, NLM locks are reclaimed for transparent switch over and clients may experience a 30-90s downtime.
   An incremental data copy begins – Live import and re-synchronization of data from the source to the destination occurs.
   NOTE:Clients are connected to the destination and the source is updated with modifications from the destination. The source is authoritative. File Creation/Write is done first on the source. When re-synchronization occurs on a file, it is marked up to date and further reads are done from the destination. For a file or directory that is not synchronized yet, all operations are forwarded to the source. During synchronization, file read can be done on the destination (partial read) for imported data already committed on this file. Some configuration changes on the destination during an import are pushed back to the source in a rollback. During an import, snapshots/backups can be created on the source VDM. Replication from the source is still active and user quota management is still active on the source VDM. When all files are synchronized, the status of the import session is shown as Ready For Commit.
6. Commit the import session – Protocol data connections to the source terminate and synchronizing modifications stop. The destination import interface is deleted and cleanup of the source system occurs. The final state is shown as Completed.

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

• Pause import – Pause can be performed when the import processing state is Copy In Progress during session create or cutover operations.
  NOTE: When a user tries to pause an import session when an incremental copy is about to complete, the session can be transitioned automatically from the Paused state to the Ready For Commit state without the user having to resume the import session. The Ready For Commit state is equivalent to the Paused state in terms of the load on the source system.
• Resume import – Resume can be performed when the import processing state is Paused.
• Cancel import – Cancel is allowed at any state of the file import session except Completed, Failed, Cancelling and Cancelled. Production interfaces are disabled on the destination side and enabled on the source side. Cancel is disruptive for NFS and SMB clients. Some changes to the configuration will be synchronized from the destination to the source. The source system is cleaned up and the destination NAS server is deleted. Cancelled is a terminal state. Cancel can be forced if the source stops responding.