We are in the midst of deploying a Synology 12-bay NAS as a high availability cluster for one of our clients. We have two model RS3614RPxs with 36TB of usable storage in each unit. We are setting them up in active/passive mode with Synology’s High Availability software.
Right away we found some shortcomings with the software.
1. We initially set it up using one of the onboard 1000BT connections. We then added a 10Gb ethernet card hoping to speed the mirror process. However, once HA is setup, the only way to change the network connection for the heartbeat connection, is to destroy the cluster, then set it back up again. This deletes all the data on the slave server and then re-mirrors all the data again. Quite a lengthy process!
2. You can bond connections together to make a faster heartbeat connection. But, see the paragraph above. You have to do this before you setup the cluster or else you need to wipe it out and start again. I installed an Intel dual 10Gbe card and then bonded those two connections together to use as a heartbeat connection to give me a 20Gbe connection between the two units.