README: more skyflake

README.md

@@ -139,30 +139,29 @@ so the following is all that is needed on a MicroVM-hosting server:
 microvm -Ru $hostname
 ```
 
-## High Availability Deployment on Nomad
-
-First, stop and delete `/var/lib/microvm/$NAME` where the
-systemd-managed MicroVMs live, or move the state to
-`/glusterfs/fast/microvms/$NAME`.
-
-```sh
-nix run .#nomad-$NAME
-```
-
 # Cluster deployment with Skyflake
 
 ## About
 
-Skyflake provides Hyperconverged Infrastructure to run NixOS MicroVMs
-on a cluster. Our setup unifies networking with one bridge per
-VLAN. Persistent storage is replicated with Glusterfs.
+[Skyflake](https://github.com/astro/skyflake) provides Hyperconverged
+Infrastructure to run NixOS MicroVMs on a cluster. Our setup unifies
+networking with one bridge per VLAN. Persistent storage is replicated
+with Glusterfs.
 
 Recognize MicroVMs for Skyflake by modules containing
 `self.nixosModules.cluster-options`.
 
-## Deploying
+## User interface
 
-Push our repo to any machine on the cluster, preferably to Hydra
+We use the less-privileged `c3d2@` user for deployment. This flake's
+name on the cluster is `config`. Other flakes can coexist in the same
+user so that we can run separately developed projects like
+*dump-dvb*. *leon* and potentially other users can deploy Flakes and
+MicroVMs without name clashes.
+
+### Deploying
+
+Push our repo to any machine in the cluster, preferably to Hydra
 because it just builds stuff and probably has most packages already in
 store.
 
@@ -175,10 +174,23 @@ select NixOS systems by the branches you push to.
 git push c3d2@hydra.serv.zentralwerk.org:config HEAD:mucbot HEAD:sdrweb
 ```
 
-## Debugging
+### Updating
+
+**TODO:** how would you like it?
+
+### MicroVM status
+
+```bash
+ssh c3d2@hydra.serv.zentralwerk.org status
+```
+
+## Debugging for cluster admins
 
 ### Glusterfs
 
+Glusterfs holds our MicroVMs' state. They *must always be mounted* or
+brains are split.
+
 ```bash
 gluster volume info
 gluster volume status
@@ -205,9 +217,15 @@ systemctl restart /glusterfs/big
 nomad server members
 ```
 
+Nomad *servers* **coordinate** the cluster.
+
+Nomad *clients* **run** the tasks.
+
 #### Browse in the terminal
 
-Use `wander` and `damon`
+[wander](https://github.com/robinovitch61/wander) and
+[damon](https://github.com/hashicorp/damon) are nice TUIs that are
+preinstalled on our cluster nodes.
 
 #### Browse with a browser
 
@@ -221,7 +239,8 @@ Then, visit https://localhost:4646 for for full klickibunti.
 
 #### Reset the Nomad state on a node
 
-After upgrades, Nomad servers may fail rejoining the cluster. Do:
+After upgrades, Nomad servers may fail rejoining the cluster. Do this
+to make a *Nomad server* behave like a newborn:
 
 ```shell
 systemctl stop nomad