Recovery time objective (RTO)
Recovery time objective (RTO) is the time that is taken to convert a secondary fileset into an active primary fileset and move applications to that site after a disaster.
After a disaster at the primary site, the secondary site becomes the
acting primary by running the mmafmctl failoverToSecondary command. The
--norestore
option is set by default. The secondary fileset is
converted to acting primary but avoids restoration of data from the last RPO snapshot and maintains
the existing data. As an administrator, you can run the mmafmctl
failoverToSecondary command with the --restore option to clean the
existing data at the secondary fileset and restore all data from the last RPO snapshot.
RTO can be estimated if the administrator knows the volume of data that is generated in an RPO interval. The volume of data that must be restored from the last snapshot depends on the number of files that changed in an RPO interval. Because a snapshot restore requires a complete scan of the snapshot to determine which files changed. The failover time is one of the components that an administrator must use to calculate the RTO for the application.