Synology dx513 delivers an effortless solution for volume expansion and data backup for selected synology diskstation models the dx513 seamlessly scales up the storage capacity of the diskstation by additional 5 hard drives on the fly when connected directly to an expansion cable when running out of hard drive capacity on the synology diskstation synology dx513 provides an easy way to immediately scale capacity by additional 5 hard drives the raid volume on the synology diskstation can be ex