docs: include section about issues with dqlite and cluster restarts

docs/faq/faq.md

@@ -24,3 +24,11 @@
     - use a docker storage driver which cleans up properly (e.g. overlay2)
     - clean up or expand docker root filesystem
     - change the kubelet's eviction thresholds upon cluster creation: `k3d create cluster --k3s-agent-arg '--kubelet-arg=eviction-hard=imagefs.available<1%,nodefs.available<1%' --k3s-agent-arg '--kubelet-arg=eviction-minimum-reclaim=imagefs.available=1%,nodefs.available=1%'`
+
+## Restarting a multi-master cluster or the initializing master node fails
+
+- What you do: You create a cluster with more than one master node and later, you either stop `master-0` or stop/start the whole cluster
+- What fails: After the restart, you cannot connect to the cluster anymore and `kubectl` will give you a lot of errors
+- What causes this issue: it's a [known issue with dqlite in `k3s`](https://github.com/rancher/k3s/issues/1391) which doesn't allow the initializing master node to go down
+- What's the solution: Hopefully, this will be solved by the planned [replacement of dqlite with embedded etcd in k3s](https://github.com/rancher/k3s/pull/1770)
+- Related issues: [#262](https://github.com/rancher/k3d/issues/262)