What is failover?

Failover is the abbreviation of English link fault pass through. The failover function (also called LFP function) refers to two connected communication devices. One (near end) has a link failure, and the link failure can be transmitted to another ( Remote) on the device.

The failover function (also called LFP function) refers to two connected communication devices (transceivers, switches, routers, etc.), one (near-end) has link failure, chain A road failure can be passed to another (remote) device. For example, the two optical transceivers A and B, the A port transceiver electrical port has a link failure, the transceiver will pass the electrical port failure to the optical port, the transceiver will stop the optical port data transmission. The transceiver at the B end does not receive the data of the A-side transceiver, and it knows that the A-side transceiver has a link failure, and the B-side transceiver stops the data transmission of the optical port and the electrical port. The LFP function enables network administrators to quickly learn and handle network failures and reduce the loss caused by network failures. Shanghai Botang Communication's transceiver supports failover function, and customers can easily set and cancel failover function through the DIP switch.

Synology SHA

SHA combines two Synology NAS servers into one High-Availability cluster (or HA cluster). One server acts as the active server and the other server becomes the standby passive server. The active server processes all data requests and services while all content is continuously replicated to the passive server. This provides a comprehensive hardware and data redundancy solution in the event of an accident

One、Create a HA base requirement

1.Hardware requirements:

HA requires two identical Synology servers as active (host) and passive (standby).

Two different Synology servers can function as active servers (hosts) and passive servers (backups), but with limitations.

2.System requirement:

Synology High Availability is supported on both the host and standby servers.

The same version of DSM must be installed on both servers.

3. Volume and hard drive:

The hard drives of both servers must be identical in size to avoid data inconsistencies.

Both the host and the standby server must have the same number of hard disks. In addition, the location of the hard disk must be the same.

Neither server can contain any volumes in SHR format. Go to the Storage Manager > volume to make sure there are no SHR volumes.

4. Network environment:

Both servers must be assigned a static IP address. Make sure that the IP addresses of both servers are accessible and belong to the same subnet, otherwise an error may occur when initializing the conversion to the standby server. To change your network settings, log in to each server and go to Control Panel > Network > Web Interface, select the web interface and click Edit.

Synology High Availability Not supported: Proxy server, DHCP, DHCP server, IPv6, PPPoE, and Wi-Fi. Be sure to turn off all of the above features before creating a high-availability cluster.

Second, connect to the server

1. Use a network cable to connect the two servers to each other. This connection acts as a "Heartbeat" connection between the two servers to speed up communication and copy data from the host server to the standby server. This connection must meet the following conditions:

>>>>The same network interface is used on both servers. For example, if one end is connected to the server's LAN 1 interface, the other end must also be connected to the LAN 1 interface of the other server.

2.Use a network cable to connect the two servers to the remaining network interfaces. Please confirm that these connections are valid and all belong to the same network.

Third, merge the server and create a high-availability cluster

Once the two servers are properly connected, you can combine them into a high-availability cluster by following the steps below.

1. Log in to the server where you want to assume the role of the active server as an account belonging to the administrators group.

2.Open the High Availability Manager.

3. Click Create HA Cluster to launch the setup wizard.

4. Specify the IP address, domain username, and password that you want to use as the standby server. (To find the IP address, log in to another server and go to Control Panel > Network > Network Interface. Remember to verify that both servers use a static IP address.) Then click Next.

5. Select the network interface to use for the high-availability cluster Heartbeat connection. (This option should be the same as the network adapter you use to connect the two servers to each other.) Then click Next.

6. Specify the name of the high-availability cluster. Also, select the network interface to connect to the data network and then specify the IP address and subnet mask for the high-availability cluster. You can access the high-availability cluster resource with the name and IP address specified here. Then click Next.

7. Confirm the settings. Then click Apply.

8.The setup wizard will begin to create a high-availability cluster. The creation time varies depending on the system environment.

9.When you are done, you will see the cluster status in the overview page.