Dell EMC Metro node 7.0.1 Administrator Guide

Auto-resume-at-loser

Determines whether the loser automatically resumes I/O when the inter-cluster link is repaired after a failure.

When the link is restored, the losing cluster finds out that the data on the winning cluster is different. The loser must determine whether to suddenly change to the winner's data, or to keep suspending I/O.

By default, auto-resume is enabled.

Set this property to true for consistency groups used in a cluster cross-connect. In this case, there is no risk of data loss since the winner is always connected to the host, avoiding out of sequence delivery.

true (default) - I/O automatically resumes on the losing cluster after the inter-cluster link has been restored.

Set auto-resume-at-loser to true only when the losing cluster is servicing a read-only application such as servicing web pages.

Set this property to false to give the administrator time to stop and restart the application. Otherwise, dirty data in the host’s cache may be inconsistent with the image on disk to which the winning cluster has been writing. If the host flushes dirty pages out of sequence, the data image may be corrupted.

false - I/O remains suspended on the losing cluster after the inter-cluster link has been restored. I/O must be manually resumed.

Set auto-resume-at-loser to false for all applications that cannot tolerate a sudden change in data.

Use the set command in the advanced context to configure the auto-resume property for a consistency group:

VPlexcli:/clusters/cluster-1/consistency-groups/TestCG/advanced> set auto-resume-at-loser true