Dell EMC Solutions Enabler 9.2 SRDF Family CLI User Guide

Use the consistency exempt option to dynamically add and remove device pairs from an active SRDF/A session without affecting:

• The state of the session, or
• Reporting of SRDF pair states for devices that are not the target of the operation

When enabled, the consistency exempt option places devices into a consistency exempt state. Exempt devices are excluded from the group's consistency check.

After the operation is complete, the consistency exempt state is automatically terminated. Specifically, consistency is terminated when:

• The target devices are resumed and fully synchronized and
• Two full cycle switches have occurred, or

  The devices are removed from the group.

The -exempt option can be used with the following commands:

• createpair

  The SRDF pairs become consistency exempt in the SRDF group in which they are created.

• movepair, half_movepair

  The SRDF pairs become consistency exempt in the target SRDF group into which they are moved.

• suspend

  Device pairs become consistency exempt in their current SRDF group. Device pairs moved from one group to another can be suspended with consistency exempt without effecting other devices in their group.

When devices are suspended and consistency exempt (within an active SRDF/A session) they can be controlled apart from other devices in the session. This is useful for resume, establish, deletepair, half_deletepair, movepair, and half_movepair operations.