Example - Decision support using the snapshot feature and the vradmin ibc command

This example shows implementing decision support using the snapshot feature and the vradmin ibc command.

To use the snapshot feature and the vradmin ibc command for decision support

  1. Create the following directory on both Primary and Secondary hosts:
     /etc/vx/vvr/ibc_scripts/dss_app
  2. Create the quiesce and unquiesce scripts and copy them to the /etc/vx/vvr/ibc_scripts/dss_app directory on the Primary host.

    In the quiesce script, provide commands to put the application that is using the Primary data volumes hr_dv01 and hr_dv02 in quiesce mode.

    In the unquiesce script, provide commands to resume the application or take it out of the quiesce mode.

  3. Create the prefreeze and onfreeze scripts and copy them to the/etc/vx/vvr/ibc_scripts/dss_app directory on the Secondary host. In the prefreeze script, include the following commands to add snapshot plexes to the Secondary data volumes hr_dv01 and hr_dv02:
    #!/bin/sh
    /usr/sbin/vxsnap -g hrdg prepare hr_dv01
    /usr/sbin/vxsnap -g hrdg prepare hr_dv02
    
    /usr/sbin/vxassist -g hrdg make SNAP-hr_dv01 datavolume-length
    /usr/sbin/vxassist -g hrdg make SNAP-hr_dv02 datavolume-length
    
    /usr/sbin/vxsnap -g hrdg prepare SNAP-hr_dv01
    /usr/sbin/vxsnap -g hrdg prepare SNAP-hr_dv01
    

    In the onfreeze script, include the following command to take the snapshot of the Secondary volumes:

    /usr/sbin/vxrvg -g vvrdg -F -P SNAP snapshot hr_rvg
    
  4. Run the following vradmin ibc command from any host in the RDS:
    # vradmin -g hrdg ibc hr_rvg dss_app london
  5. On the Secondary, use the snapshot data volumes SNAP-hr_dv01 and SNAP-hr_dv02 to run the DSS application, that is, for off-host processing.
  6. When the DSS application completes, reattach the snapshot plexes to the data volumes by issuing the following command on the Secondary host london:
    # vxrvg -g hrdg snapback hr_rvg

    The snapback destroys the SNAP volumes and reattaches the snapshot plexes to their original volumes. If you have enabled FR on these volumes, the reattach is faster.