In preparing for the possible funding to upgrade some end-of-live de-duplication appliances, some sales team presentations and responses to asked questions failed to clarify critical network connection details required for this project. I was seeking clarification from others in the forums to see if they had any experience with the setups the prospective vendors are pushing that differ from those already established in the current end-of-life hardware.
Current configurations in use today have a single backup server that handles sending 95% of the backup data to multiple de-duplication appliances. Two appliances share a Gig-E LAN used for network backups with the backup server using port aggregation for 4 Gig-E interfaces on the backup server to the LAN.
The largest amount of data is sent over a fibre crossover cable between the backup server and the larger of the de-duplication appliances. Originally we had tried to use the port aggregation setup on the backup server and the de-duplication appliance but found that it was not performing as we had been lead to believe originally. It turned out that in the port aggregation setups worked well for many hosts to a backup appliance or many hosts to a single backup server, a single backup server to a single appliance did not work well. This was due to the way the various port aggregation protocols are implemented using MAC addresses to load balance data packets. Even with 4 Gig-E interfaces on the server and 3 on the de-duplication appliance we were only getting speeds of ~95 MB/s on the Gig-E (~128 MB/s max) links. Network team troubleshooting found that the switch was always routing the connections between the two devices to the same MAC addresses. Our final solution in this case was to go to 10Gb.
Now the various prospective vendors are pushing the ideas of using multiple interfaces on their appliance but instead of port aggregation, they are pushing bonding of the interfaces at the OS level. I know in Linux this works quite well and all the appliances I have come across are embedded Linux. I can see that for packets out of the de-duplication appliance they can go via any of the bonded Ethernet NIC to the switch to theoretically increase outbound performance. As of yet I have not gotten a strong answer on how inbound traffic will be handled.
A question I have for anyone doing this type of configuration, bonding up to 6 interfaces on a de-duplication appliance to the network and pushing data from a single server, with multiple bonded or port aggregated interface, to the bonded interface set on the appliance, is how well it works.
Secondly I would like to know what sorts of speeds you are able to achieve.
In my mind it would be no different than pushing data via a port-aggregated link as the switch may see up to 6 copies of the same MAC, it would now know how to pick which one should get the data even if the bonded interface on the appliance is set to something like round-robin.
Thanks!
