I'm looking for something that can replicate file systems between multiple branch locations. Our file servers currently run CentOS 7.
I feel like there has to be a better solution that what we're using now. Currently we have 2 branches, and I'm using lsyncd with csync2 bidirectionally to keep the filesystems in sync. We're adding a 3rd branch soon, and while the lsyncd/csync2 combination can do that, it has already shown that it can be fragile with only 2 locations, and I'm afraid adding a third will make it worse. The branch offices are connected by a VPN over DSL/Cable, so anything that can't survive a high latency connection won't work (eg: GlusterFS)
Most of the replicated filesystems I've encountered are designed so that the replica is meant as a failover, so the replica can't be used unless it's the master. I need the replicas to be usable for read/write at all times.
It seems like this would be a common scenario in business, with multiple branch offices, but I can't seem to find anything that looks like it will work the way I want.