The Buffalo TeraStation™ 3000, 4000, 5000 & 7000 support real time backups through replication.
Replication mirrors the data in a folder on the source TeraStation™ to a share on another TeraStation™ in near real time. After the initial mirroring of data, only changes at the byte level across the network. Replication is like a synchronization, not like a backup. After the writing of a file on the source it will be replicated automatically onto the destination.
Each replication task works only in one direction: from the source to the destination. Changes or deletions on the destination are not reflected back to the source, but all changes, additions and deletions made on the source are reflected on the destination.
Should the main unit fail you could simply make a few setting adjustments to continue work with the second unit.
In an office you need high availability for certain data in a network and therefore it is necessary to plan for the worst case scenario. You would replicate all data for high availability to a second TeraStation™ in the same network. Should the main unit fail you could simply make a few setting adjustments to continue work with the second unit. You could even load the saved settings of the first unit to the second one using the Buffalo utility for saving and restoring settings.
To be safe in case of physical damage like water, fire etc. it is common practice to hold all files on a second location. In company network the destination TeraStation is placed in another fire zone or another campus building. If there is more than one network, use simple port forwarding in a router/firewall enables two TeraStation™ to replicate all business relevant data from one location to another one.
This works in the same way utilising a VPN connection. All the routing is managed by the company router/firewall and in the ideal case it works like in a LAN.
Nevertheless it is possible to add a target manually in case the automatic detection has difficulties.
Replication is a 24/7 online synchronization between folders on the Source and Destination TeraStation™.
Failover with Buffalo TeraStation
The Buffalo TeraStation™ supports fail over fault tolerance in the network.
Fail Over is different to Replication. In Fail Over scenario there are at least two TeraStation present in one network but only one TeraStation can be seen as a device. The second unit is hidden but directly communicating with the first unit. So the data stored on the first is mirrored to the second immediately. The “magic” behind is the behavior of the second in case of fault of the first. As soon as the first unit disappears from the network – maybe due to power failure, network failure or whatever – the second, hidden unit appears and takes over the place from the first one. The failover mechanism allows the second unit to act identically like the first, unavailable unit. Even the Mac-Addresses, the hostname, the IP-Addresses, the complete “personality” of the first one is taken by the second one.
Failover means that in case of unavailability there is a little gap in time until everything works again from the perspective of the user. Behind the scene the TeraStation exchanged their positions to avoid any lack in workflow and operation.
Failover is based on the Spanning Tree control mechanism.