Expand the storage capacity of your Synology rack-mounted SAS by 12 bays at a time, with the ability to add up to 84 additional 3.5"/2.5" SAS/SATA drives, with a maximum of seven Synology RX1222sas expansion units. Add volumes whenever and wherever necessary without interruption of services, thanks to the online volume expansion and powerful volume management options of Synology DiskStation Manager (DSM).