Can I create a high-availability cluster with two different Synology NAS?
Can I create a high-availability cluster with two different Synology NAS?
Purpose
Important:
- Starting from the 25-series models, hybrid high-availability clusters are no longer supported. You must use two identical Synology NAS that support Synology High Availability. To check supported models, click Applied models in the upper-right corner of this webpage.
When creating a high-availability cluster, it is always recommended to use two identical Synology NAS. However, it is possible to create a hybrid high-availability cluster using two similar models temporarily before you acquire two identical ones. This article will cover the limitations of hybrid high-availability clusters.
Resolution
Requirements:
- To ensure the stability of the high-availability cluster, it is strongly recommended not to consume resources that exceed the specifications of both the active and passive servers.
- The number of drive bays and installed disks must be identical in both the active and passive servers.
- If a Synology Expansion Unit is connected to the active server, the disks and volume allocations in the passive server and its Expansion Unit must be identical to ensure normal auto failover or switchover.
- If the hosts have different numbers of LAN ports, you will not be able to configure the redundant ports, and the ports cannot be used for the cluster connection.
Services monitored in hybrid high-availability clusters:
If any of the following service fails on the active server, the system will fail over to the passive server (as long as the passive server is operating normally).
-
File Services1
- Windows File Service
- Mac File Service
- NFS File Service
- FTP Service
- iSCSI/Fibre Channel
- Synology Directory Server
Package limitations:
- Surveillance Station: If the service is switched to the server that has a lower maximum camera capacity, the IP cameras that exceed the limit will be stopped.
- Virtual Machine Manager: This package is not supported on hybrid high-availability clusters.
Hardware/system limitations:
- When setting up a hybrid high-availability cluster with two Synology NAS models that differ in specifications, such as CPU frequency, RAM capacity, or maximum connections/shared folders supported, you may experience performance issues if the system service is switched to the slower server. In such cases, you will not be able to create or modify system configurations that exceed the specifications of the switched server.
Synology models allowing hybrid high-availability clusters:
The following table lists the model combinations that support hybrid high-availability clusters and the minimum DSM version required by each combination.2 3 4
Model Combination | Minimum DSM Version Supported |
---|---|
FS6400, FS3017 | DSM 6.2.2 |
FS3600, FS3400 | DSM 6.2.3 |
FS3600, FS2017 | DSM 6.2.3 |
FS3400, FS2017 | DSM 6.2.2 |
SA3610, SA3600, SA3410, SA3400 | DSM 7.1.1 |
SA3600, SA3400 | DSM 6.2.2 |
SA3600, RS18017xs+ | DSM 6.2.2 |
SA3600, RS18016xs+ | DSM 6.2.2 |
SA3400, RS18017xs+ | DSM 6.2.2 |
SA3400, RS18016xs+ | DSM 6.2.2 |
RS18017xs+, RS18016xs+ | DSM 6.1 |
RS4021xs+, RS4017xs+ | DSM 6.2.3 |
RS3621xs+, RS3617xs+ | DSM 6.2.3 |
RS3621RPxs, RS3617RPxs | DSM 6.2.3 |
RS3618xs, RS3617(RP)xs | DSM 6.2 |
RS3617xs+, RS3614xs+ | DSM 6.0.1 |
RS3617(RP)xs, RS3614(RP)xs | DSM 6.0.1 |
RS2821RP+, RS2818RP+ | DSM 6.2.4 |
RS2423(RP)+, RS2421(RP)+5 | DSM 7.1.1 |
RS2421(RP)+, RS2418(RP)+ | DSM 6.2.4 |
RS2418(RP)+, RS2416(RP)+ | DSM 6.1 |
RS2416(RP)+, RS2414(RP)+ | DSM 5.2 |
RS1221(RP)+, RS1219+ | DSM 6.2.3 |
RS822(RP)+, RS820(RP)+ | DSM 7.1 |
RS820(RP)+, RS818(RP)+ | DSM 6.2.2 |
RS818(RP)+, RS815(RP)+ | DSM 6.1 |
RS815(RP)+, RS814(RP)+ | DSM 5.2 |
RS815(RP)+, RS812(RP)+ | DSM 5.2 |
RS814(RP)+, RS812(RP)+ | DSM 5.2 |
DS3622xs+, DS3617xsII | DSM 7.0.1 |
DS3622xs+, DS3617xs | DSM 7.0.1 |
DS3617xsII, DS3617xs | DSM 6.2.4 |
DS3617xsII, DS3615xs | DSM 6.2.4 |
DS3617xs, DS3615xs | DSM 6.1 |
DS3615xs, DS3612xs | DSM 5.2 |
DS2422+, DS2419+II | DSM 7.0.1 |
DS2422+, DS2419+ | DSM 7.0.1 |
DS2419+II, DS2419+ | DSM 6.2.4 |
DS2419+II, DS2415+ | DSM 6.2.4 |
DS2419+, DS2415+ | DSM 6.2.2 |
DS2415+, DS2413+ | DSM 5.2 |
DS1821+, DS1819+ | DSM 6.2.3 |
DS1819+, DS1817+ | DSM 6.2.2 |
DS1817+, DS1815+ | DSM 6.1.1 |
DS1815+, DS1813+ | DSM 5.2 |
DS1815+, DS1812+ | DSM 5.2 |
DS1813+, DS1812+ | DSM 5.2 |
DS1621+, DS1618+ | DSM 6.2.3 |
DS1522+, DS1520+ | DSM 7.1 |
DS1517+, DS1515+ | DSM 6.1.1 |
DS1515+, DS1513+ | DSM 5.2 |
DS1515+, DS1512+ | DSM 5.2 |
DS1513+, DS1512+ | DSM 5.2 |
DS923+, DS920+ | DSM 7.1.1 |
DS920+, DS918+ | DSM 6.2.3 |
DS918+, DS916+ | DSM 6.1.4 |
DS723+, DS720+ | DSM 7.1.1 |
DS720+, DS718+ | DSM 6.2.3 |
DS718+, DS716+ | DSM 6.1.4 |
DS716+, DS713+ | DSM 5.2 |
DS916+, DS415+ | DSM 6.0.1 |
DS423+, DS420+ | DSM 7.1.1 |
DS415+, DS412+ | DSM 5.2 |
DS224+, DS220+ | DSM 7.2 |
Notes:
- Check the applied models of Btrfs at the bottom of this webpage.
- Check the applied models of Synology High Availability on this webpage.
- In a hybrid high-availability cluster where one model has built-in M.2 slots and the other only has a PCIe slot for an M.2 expansion card (e.g., DS1621+ and DS1618+), M.2 SSD caching is not supported.
- When two models have different LAN port speeds, the hybrid high-availability cluster's LAN port speed will be capped at the lower one.
- Check the recommended network setup on this webpage.