The native file import feature provides a native option for file migration to Dell Unity from a VNX1 or VNX2 system. This feature supports allows for migrating a VNX VDM and file systems to a Dell Unity NAS server. Native file import was developed to handle the communication and data transfer between VNX and Dell Unity. This enables ability for the migration to be transparent to host IO for NFS clients due to the stateless nature of the protocol. This feature allows for a full rollback to the VNX VDM without user data loss at any time before the migration is committed.
Some preparatory work is required on the VNX system, but creation, monitoring, and cutover are all managed on Dell Unity. This feature is fully supported through Unisphere, as well as UEMCLI and REST API. Due to the Unified nature of Dell Unity, only one remote system connection is required to leverage both the native file import and native block import features.
OE version 4.1 includes support for NFSv3, and OE version 4.2 includes support for SMB.
OE version 5.1 adds support for multiprotocol where both NFSv3 and SMB are used. When performing a multiprotocol file import, it is important to note the Access Policy differences between VNX and Dell Unity. Some access policies behave differently on VNX compared to Dell Unity and some VNX access policies are no longer available. Depending on the configuration, client access behavior may be impacted after the migration. The table below shows the access policy mappings that are used when performing a multiprotocol import along with the access policy differences.
VNX Access Policy | Dell Unity Access Policy | Differences |
NATIVE | NATIVE | Same behavior between VNX and Dell Unity |
NT | WINDOWS | VNX: SMB clients only need to check the Windows permissions |
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| VNX: NFS clients check both UNIX and Windows permissions |
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| Dell Unity: Both NFS and SMB clients only need to check Windows permissions |
UNIX | UNIX | VNX: NFS clients only need to check the UNIX permissions |
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| VNX: SMB clients check both UNIX and Windows permissions |
OE version 5.1 adds support for stub-aware migrations when using native file import. Previously, any stub files on the source file system are migrated as rehydrated full files on Dell Unity. The stub-aware migration feature works on SMB, NFS, and multiprotocol imports. To enable this functionality, the backup policy must be set to offline (default is passthrough) on VNX and parameter imt.dhsmEnabled=1 (default is 0) on Dell Unity. The offline option enables the backup of stubs on VNX and the parameter directs native file import to migrate stubs instead of full files.
For more information about Dell Unity Native File Import, reference the Dell Unity: Migration Technologies white paper and the VNX Series Data Import to a Dell Unity System User Guide on Dell Technologies Info Hub.