I agree. I was also thinking of Ceph when I wrote my reply to Cantrill. Esp Ceph on XFS given maturity of both plus enormous effort that's gone into XFS. Sector/Sphere with UDT is also kick-ass. It took both of these a long time to get to where they were fighting all kinds of unforseen issues. They also tried to build on proven components that themselves were battletested for years.

So, this company is trading away stuff like that for custom components and Etcd? And for a component focusing on integrity and availability? Huh?

  I've managed to lose data with Etcd

How did you manage to lose data?

Use etcd in production and you will lose data. Bounce nodes, simulate power loss and you will lose data. Have you actually used it?

I don't remember the details, and to be clear this was not with the most recent version of Etcd at all - it was quite a while ago. I think and hope that whatever the problem was is no longer an issue. It has certainly gotten a lot better. My point is mainly that it is way too young to be something to trust important data to. We didn't either - what we lost was a cluster configuration that we could recreate from a combination of backups and redoing a handful of operations, but at the time it was scary to see, and prompted us to be very careful about what we put into Etcd going forward.