## Context
`modules/kubernetes/nfs_volume` creates the K8s PV but NOT the underlying
directory on the Proxmox NFS host (`192.168.1.127:/srv/nfs/<subdir>`).
The first time a new consumer is added, the mount fails with
`mount.nfs: … No such file or directory` and the pod hangs in
ContainerCreating.
This bit us twice during the Wave 1/2 rollout — once for the mailserver
backup (code-z26) and again for the Roundcube backup (code-1f6). Both
times the fix was `ssh root@192.168.1.127 'mkdir -p /srv/nfs/<subdir>'`.
Rather than automate the SSH dependency into the module (which would
break hermeticity and fail for operators without host SSH), this runbook
documents the manual bootstrap step and the rationale.
Addresses bd code-yo4.
## This change
New file: `docs/runbooks/nfs-prerequisites.md`. Lists known consumers,
gives the copy-paste SSH command, and explains why auto-creation was
rejected (two options, neither worth the churn).
## What is NOT in this change
- Any automation of the bootstrap — runbook only
- Migration to `nfs-subdir-external-provisioner` — explicitly out of scope
## Test Plan
### Automated
```
$ cat docs/runbooks/nfs-prerequisites.md | head -5
# NFS Prerequisites for `modules/kubernetes/nfs_volume`
The `nfs_volume` Terraform module creates a `PersistentVolume` pointing at a
path on the Proxmox NFS server (`192.168.1.127`). It does **not** create the
underlying directory on the server.
```
### Manual Verification
Before the next stack adds a new `nfs_volume` consumer, read the runbook
and run the `ssh root@192.168.1.127 'mkdir -p ...'` step. First pod
reaches Ready within a minute of the PV creation.
Closes: code-yo4
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
c6784f87b5