Mapping remote command devices for delta resync operations

For information about command device and remote command device configurations, see Setting up remote command devices for use with RAID Manager.

Procedure

  1. Set a path for the external port and target port of each site.

    For details about the external port, see the Universal Volume Manager User Guide. For details about port and LU path settings, see the Provisioning Guide .

  2. Set command devices for all sites.

    For details about setting command devices, see the Provisioning Guide .

  3. In the site in which you are creating a pair, map command devices in all sites as remote command devices.

    For details about mapping remote command devices, see the Universal Volume Manager User Guide.

Results

When the above procedure is performed, the status of each site changes as follows:
  • Each site has two command devices mapped to the other two sites through two target ports.
  • Each site has two remote command devices mapped from the other two sites through an external port.

In the Logical Devices window, logical devices that are command devices or remote command devices are displayed as Command Device or Remote Command Device (in the Attribute column in HDvM - SN). In RAID Manager, command devices are displayed as CMD for VOL_ATTR of the raidcom get ldev command, and remote command devices are displayed as RCMD for VOL_ATTR of the raidcom get ldev command. For details about the Logical Devices window, see the Provisioning Guide .

The following figure shows a configuration of command devices and remote command devices.

When mapping of remote command devices to each site is complete, you must assign mirror IDs to the remote command devices. This operation is required for delta resync operations.

Parent Topic
  • Delta resync configuration

    With the delta resync configuration, you bring the S-VOL to a consistent state more quickly after failure because only missing differential data must be copied.