Replication may stop if the disks are write cache enabled

In some hardware configurations, if the standard Windows write back caching is enabled on the Secondary, replication may stop for prolonged time periods. In such cases, update timeout messages appear in the primary system event log. Because the Secondary is slow to complete the disk writes, a timeout occurs on the Primary for acknowledgment for these writes. (343556)

Workaround: Before setting up replication, disable write caching for the disks that are intended to be a part of the RDS. You can configure write caching through Windows Device Manager by right-clicking the disk device under the Device drives node and selecting Properties > Policies.