Trucking features in AFM DR

AFM DR trucking feature can be used to synchronize data between the primary and secondary filesets when the DR relationship is established for the first time.

Features

  • AFM DR requires the same data between the primary and secondary before a DR relationship is established by using the peer-to-peer snapshot (PSNAP) mechanism. If the data on the primary and secondary are the same, the peer-to-peer snapshot mechanism creates a special snapshot called PSNAP0. The PSNAP0 is created on both the primary fileset and the secondary fileset.
  • Two trucking methods are supported by AFM DR:
    • Inband trucking: AFM DR copies the data from the primary to the secondary using the DR transport protocol (NFSv3 or NSD). After the copy is complete, the primary and secondary have the exact same data and PSNAP0 is created.
    • Outband trucking: It is the user’s responsibility to copy all the data from the primary and secondary by using any mechanism that they choose. For example, rsync with mtime preserved. After all the data is copied, the user can use the AFM DR commands to establish the DR relationship that creates the PSNAP0.
Note: Both methods use the --inband option of the mmafmctl command while setting up the relationship between the primary and secondary sites.

For more information about the two trucking methods, see Converting GPFS filesets to AFM DR. See the following use cases for recommendation on when to use inband versus outband trucking.