The proxmox-csi-plugin hardcodes a 29-disks-per-VM ceiling in
pkg/csi/utils.go:394 (lun < 30 loop). This is the actual block-
storage scaling bottleneck — NOT QEMU, NOT Proxmox, NOT the kernel.
Adds a "Per-VM SCSI-LUN cap" section to docs/architecture/storage.md
explaining:
- the source-level hardcode and how to recognise it (FailedAttachVolume
"no free lun found")
- why switching scsihw to virtio-scsi-single buys ZERO additional
capacity (perf-only)
- levers in leverage-per-effort order (migrate non-DB to NFS,
add a worker, fork+patch the plugin)
- the Wave 1 NFS migration (2026-05-26) that took 5 services off
block and skipped two more on pre-flight (plotting-book SQLite+WAL,
stirling-pdf H2 .mv.db)
Discovered during the Wave 1 work — see remote memory ids 2788+ for
full context and 2798+ for the related postiz state-drift discovery.
6e9bffb1a3