On July 23rd, Coraid successfully demonstrated that AoE LUNs can be accessed over an IP network, using the public Internet and over leased-line IP connections. To do this, AoE frames were passed through a GRE tunnel created using standard router equipment.
The Proof of Concept (POC) connection was made from the Coraid offices in Athens, GA to a customer site in Fort Worth, TX. Although the T1 line used in the POC was too small for bulk data transfer, it was more than adequate to support bi-directional remote management of SR disk shelves via a CEC connection.
Coraid Engineering is working on a new release of the storage virtualization software for the VS-series appliances that will allow asynchronous LUN replication. With the news that AoE can be transported over WAN links, we are hopeful that given sufficient bandwidth, replication will be possible to remote site storage shelves.
Potential Application examples -
1) A large database needs to be replicated to a remote site. Users would initially create a baseline synchronization of the database to a local EtherDrive RAID LUN, then remove the disks from the storage appliance and ship them to the remote backup site and install them in a similar EtherDrive storage appliance. This first step is easy because Coraid EtherDrive appliances store all the RAID configuration on the RAIDed disks and the remote storage chassis learns the configuration from the disks when they are installed at the remote location.
Once the remote AoE device is online, a GRE tunnel can be used between the primary and backup site to allow the primary and backup LUNs to be kept synchronized by directly using AoE without using software like rsync or drbd.
This will be possible by using the VS-21 EtherDrive VirtualStorage appliance. A feature called LUN replication will asynchronously synchronize with the remote site. As long as the rate of change in the database does not create an excessive time lag caused by the bandwidth of the AoE tunnel, we believe useful remote asynchronous LUN replication is possible.
2) The AoE tunnel may also be useful for WAN access to the console port on a remote EtherDrive storage appliance using the Coraid Ethernet Console (CEC) program.
We will be posting setup details on the web site Resources Tab, App Notes page. Your questions and comments are welcome.
Coraid Engineering Staff
