a data storage system configured for efficient mirroring of data between paired redundant controllers is provided . more particularly , in response to the receipt of customer data from a host for storage , a first controller segments the received customer data into one or more frames of data . in addition , the first controller determines or associates certain metadata for each frame of customer data , and inserts that metadata in the corresponding frame . the frames , including the metadata , are provided to a secondary controller . the secondary controller stores the customer data from a received frame in memory , and stores the corresponding metadata in another location of memory that is indexed to the location where the customer data was stored . the secondary controller may also associate a count value with each frame of data in order to distinguish the most recent frame of data should frames in memory have matching metadata .