Disclosed are, inter alia, methods, apparatus, data structures, computer-readable media, and mechanisms for maintaining counters, such as in, but not limited to a packet switching system, and updating a secondary counter storage based on values of the counters and entries in an overflow buffer. Multiple counter values are stored in a counter bank. An indication of a particular counter of the multiple counters to update is received. A current value of the particular counter is updated in the counter bank, and if an overflow condition results, then an indication of the particular counter is added to an overflow buffer. Periodically each of the multiple counters is visited and corresponding values are updated in a secondary storage, and each entry is retrieved from the overflow buffer and a corresponding value is updated in the secondary storage.