What happens when connectivity to the origin system is lost

You can control how the FlexCache volume functions when connectivity between the caching and origin systems is lost by using the disconnected_mode and acdisconnected volume options.

The disconnected_mode volume option and the acdisconnected timeout, combined with the regular TTL timeouts (acregmax, acdirmax, acsymmax, and actimeo), enable you to control the behavior of the FlexCache volume when contact with the origin volume is lost.

When you configure the FlexCache disconnected options, you should consider the following questions:

• Would your applications or file access protocols react better if an I/O request returned an error or if it did not return at all?
• How long can you safely serve stale data when connectivity is lost?

The following flowchart shows the multi-step decision process used by Data ONTAP to determine what happens when a FlexCache volume is disconnected from its origin volume. The possible outcomes of this process are:

• The data is served.
• An error is returned.
• The operation hangs.