User`s guide

Synology NAS User's Guide

Based on DSM 4.3

92 Chapter 18: Provide Nonstop Service with Synology High Availability

Passive Server

Under normal conditions, the passive server remains in standby mode. Data on the active server is continuously

replicated to the passive server. In the event the active server cannot provide services, you or the system can

initiate a switchover to the passive server.

Install Synology High Availability

Synology High Availability can be installed by going to Main Menu > Package Center.

System Requirements

Implementation of Synology High Availability requires two identical Synology NAS servers to act as active and

passive servers

System Requires

. 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.

 Synology NAS: Both the active and passives servers must be identical models and support Synology High

Availability.

 DSM Version: The same version of DSM must be installed on both the active and passive servers.

 Package Version: The same version of Synology High Availability must be installed on both Synology NAS

servers.

Volume and Hard Disk

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

 Storage Volume: In order to accommodate data replication, the storage capacity of the passive server must

be equal to or larger than the capacity of the active server. It is strongly advised that the storage capacity of

both servers be completely identical to reduce the chances of inconsistencies.

 Number of Disks: Both the active and passive servers must have the same quantity of hard disks. In addition,

hard disk numbering and position must correspond in both servers.

 SHR Format Unsupported: SHR format volumes are not supported. Please ensure that the Synology NAS

server which will act as the active server does not contain SHR volumes.

Network Environment

Please note the following guidelines regarding network settings.

 Network Settings: Both servers of the high-availability cluster must be assigned static IP addresses. Please

ensure that your Synology NAS servers are both configured with static rather than DHCP IP addresses. In

addition, ensure that the IP addresses of both servers are accessible and belong to the same subnet;

otherwise errors might occur when initiating a switchover to the passive server.

 Number of LAN Ports: Both servers must have the same number of LAN ports. If your Synology NAS is

equipped with additional network card interfaces, these network cards also count as additional LAN ports.

 PPPoE Unsupported: Synology High Availability does not support PPPoE. Please ensure that PPPoE is

switched off before creating a high-availability cluster.

 Wi-Fi Unsupported: Synology High Availability does not support Wi-Fi. Please ensure that Wi-Fi is switched

off before creating a high-availability cluster.

---------

Synology High Availability can only be installed on certain models.