The 7210 SAS uses an index file to store the map that indicates the QoS resource allocation to the SAPs. This file is used to ensure that all the SAPs that were created successfully before the reboot can be recreated during reboot. Without an index file, it is possible that all the SAPs that were configured successfully may fail on a reboot after saving the configuration file. The index file is stored in the flash. During a reboot, if the file is found, the system allocates resources as per the stored map. If the file is not found, the system implements a best-fit algorithm and attempts to allocate resources for all the SAPs on a first-come-first-served basis. There is no guarantee that resources will be allocated to all SAPs. When the index file is not present, it is possible that saved the configuration does not execute successfully after the reboot.
The index file used for QoS maps is different from the one used for storing interface indexes.