Limitations and System Requirements
Implementation of Synology High Availability requires two identical Synology servers to act as active and passive servers. Before the two servers are combined into a high-availability cluster, system will check for the following hardware and software limitations to ensure that a high-availability cluster can be created.
System Requirements
Please note the following guidelines regarding software and hardware:
- Synology Server: Both the active and passives servers must be identical models.
- Expansion Unit(s): Both the active and passive servers must connect to same expansion units correctly.
- Number and Type of Drives: Drive type must be SAS only. Before installing DSM, you have to install at least 3 drives in the expansion unit(s).
- USB External Device: Only USB storage is supported. Other USB external devices (e.g., UPS, Wi-Fi dongle, Speaker, Printer, Bluetooth dongle and DVB dongle) are not supported. USB storage can be used in the active server only, and cannot be switched to the passive server.
Network Environment
Please note the following guidelines regarding network settings when attempting to form a high-availability cluster.
- Network Settings: The Heartbeat connection between the two servers must be set up correctly. Both servers must belong to the same subnet, and it is required to configure static IP addresses after installation.
- Number of LAN Ports: Both servers must have the same number of LAN ports. If one of your DiskStation models is equipped with additional network card interfaces, the other one must be equipped with the same network card interfaces.
- Connection Restrictions: Wi-Fi network is not supported by the high-availability cluster.
Note:
- NTP server will be automatically enabled on the active server.
Package and Software Limitations
Please see the package and software related limitations below:
- The high-availability cluster does not support the following packages and features:
- DVBLink Server
- The feature to reboot/shut down the high-availability cluster in CMS
- Time Backup
- High-availability cluster with shared storage cannot be configured as or used in combination with a replication-based high-availability cluster.
Specific Expansion Units
Both the active and passive servers must be connected to the specific expansion units. There are two modules on each expansion unit.
To setup/add expansion units:
- A module contains two ports; the input port is on the left side, and the output port on the right side. Connect a SAS cable from the output port of a module to the input port of the next expansion unit's module.
- The expansion units must be connected serially with the modules on corresponding sides for each server.
- Both the active and passive servers must be connected to the shared expansion units in the same order.
Notes:
For detailed information regarding expansion unit installation, please remember to see the Quick Installation Guide for your servers and expansion units.