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, the Synology High Availability Wizard 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:

Volume and Hard Disk

Please note the following guidelines regarding RAID Group, volume, and hard disk management.

Network Environment

Please note the following guidelines regarding network settings.

Notes: Telnet and SSH functions will be automatically enabled once the high-availability cluster is created.

Storage Manager Limitations

Once a high-availability cluster has been created, certain options in Storage Manager will be unavailable.

Adding Expansion Units

Once a high-availability cluster has been created, expansion units can be added to your existing high-availability cluster configuration in order to expand storage capacity. As with other hardware requirements, identical expansion units are required for both the active and passive servers. To avoid inconsistency errors, please be careful to follow the instructions below when adding any expansion units.

To add expansion units:

  1. Only add identical expansion units and hard disks to the active and passive servers. As stated above, the hardware of both the active and passive servers must be identical, including hardware model, and hard disk size and position.
  2. Make sure to delete all existing data and volumes on the hard disks in the expansion units.
  3. Connect expansion units to the active and passive servers when both servers are powered on and running.
  4. Create new RAID Groups on the expansion unit before powering off either of the servers.

Notes: For basic information regarding expansion unit installation, please remember to see the user's guide for your expansion unit.