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Configuring Failover on Buffalo TeraStation 5010/3010

What Is Failover?

With failover, two TeraStations are connected to the network for redundancy. If a problem occurs in the main TeraStation that causes it to become inaccessible, operation is automatically switched to the backup TeraStation.


In order to configure failover, certain conditions must first be met:

  1. The TeraStations must be identical models and have identical capacities. If the capacity of the main TeraStation is larger than that of the backup TeraStation, configuring failover will cause an I33 error to occur.
  2. All drive bays of a TeraStation should be occupied if it will be used for failover. Failover will not work if a drive is missing from any bay.
  3. Use static IP addresses for both TeraStations. Because the IP address of the TeraStation designated as the backup cannot be changed, set its IP address before configuring failover. For more information on configuring static IP addresses see here.


Usage Restrictions

Failover cannot be set up if any of the following functions are enabled:

Replication, sleep mode, encrypted disk volume, MySQL server, media cartridge, LVM volume, iSCSI volume, port trunking, cloud storage, Dropbox Sync,  surveillance server, hot spare, access restrictions by Active Directory or NT domain

The following operations will not be available while failover is enabled:

Initializing settings, changing the RAID settings, formatting drives, iSCSI volume, changing the backup unit's settings

Non-Transferable Settings

The settings below are not copied from the main TeraStation to the backup TeraStation. Make a note of the original settings so that they can be configured manually if the backup TeraStation replaces the main TeraStation.

WebAccess, UPS synchronization, antivirus, the Backup job settings either if specifying shared folders on the backup TeraStation or USB drives as the backup destination, and USB drives’ shared folder settings

Using with a UPS

Once failover is configured, you cannot set up UPS sync for the backup TeraStation. Configure your UPS before configuring failover. UPS recovery can be configured for both the main TeraStation and the backup TeraStation. However, the UPS settings of the main TeraStation will not be copied to the backup TeraStation.

If the backup TeraStation is configured to sync with the UPS connected to the main TeraStation, and the main TeraStation shuts down, the backup TeraStation will no longer be able to detect if there was a power outage. In this case, move the UPS communication cable from the main TeraStation to the backup TeraStation and reconfigure the UPS link settings.


There are two options for failover cabling: using LAN port 1 only or using both LAN ports.

Using LAN port 1 only


The backup TeraStation is updated over normal network traffic.

Using both LAN ports (Preferred)


With the second setup, the backup TeraStation and main TeraStation are connected by a second Ethernet cable connecting their respective LAN 2 ports. For TeraStation 5010 series, it is recommended to use the 10GbE port (LAN port 3) for failover. Updating is done over this dedicated network path, so updates are quicker and don't interfere with normal network traffic.



  1. Access TeraStation's Settings and click on the "Backup" tab from the left hand column.
  2. Click on the configuration icon to the right of "Failover".
  3. Click Configure Failover in the upper right corner to start failover configuration.


  1. Select a TeraStation to be the backup destination device and enter its administrator username and password.


  1. Select the LAN port to be used for sharing files and enter a virtual IP address and subnet mask.

About Virtual IP Address:

A virtual IP address is an IP address that will be used for file sharing while failover is configured. By assigning a different IP address from the one to be assigned to the LAN port, you can access the TeraStation for sharing files, as well as open Settings using the virtual IP address. This IP address will be inherited to the backup TeraStation when failover occurs, so you can access the backup TeraStation even if you don’t know the backup TeraStation’s static IP address.

Configure an unused IP address for the virtual IP; make sure it uses the same segment as the main and backup TeraStations.

  1. Select the Backup LAN port to be used for transferring data via failover

           • LAN Port 1 for Alive Check and LAN Port 2 for Failover

                Select the IP address labeled “(LAN1)” for the LAN port setting of “IP Settings for File Sharing” and select “(LAN2)” for “Backup LAN Port” in Settings.

           • LAN Port 2 for Both Alive Check and Failover

                Select the IP address labeled “(LAN2)” for the LAN port settings both “IP Settings for File Sharing” and “Backup LAN Port” in Settings.

  1. Configure whether or not to inherit subfolders’ access restrictions to the backup TeraStation, then click Continue.


  1. If the administrator username and password is correct, the backup TeraStation will beep.
    Press and hold the function button to accept the settings from the main TeraStation. (When you press the function button, the backup TeraStation will stop beeping. Keep holding it down until the backup TeraStation beeps again.)

  1.  The following screen appears on the primary TeraStation until failover is fully operational. Wait until initialization finishes. The amount of time required will vary depending on the amount of data already stored on the primary TeraStation.  (I51 message will display on the LCD panel and NAS Navigator2 for both TeraStations.)


  1. Failover is configured after it finishes and the I51 message disappears on the TeraStation LCD.


  1. Once the process is complete the primary TeraStation will show a status of "Normal (Main Device)" in the Failover section of Settings. Failover is now configured.


  1. Access Settings for the backup TeraStation. The following screen appears. At this point, the backup TeraStation's Settings page will not be accessible without stopping failover. Click Log Out and exit Settings for the backup TeraStation.

Please note that the RAID array on the backup TeraStation may be reconfigured and resynchronize as part of the failover process. This is expected behavior and not an error.