This gauge measures the current usage of the High Availability sync send queue in octets rather than packet count, giving a byte-level view of queued sync data. It helps an administrator judge queue pressure in terms of actual data volume, which matters when sync packets vary widely in size. For example, comparing this octet count against clvHASyncSendQueueUsagePackets could reveal that the queue is filling with a few very large synchronization updates rather than many small ones.