Install Ubuntu 24.04 Server on ZFS Root via Autoinstall

This is a tiny delta to my previous guide (HTTPS + Nginx + SSI already working).

Install Ubuntu 24.04.2 with NoCloud Autoinstall over HTTPS

The focus here is switching user-data to ZFS root while keeping everything else the same.

ZFS in 60 Seconds (Why Use It)

Copy-on-write + checksums detect silent corruption (and self-heal on mirrors/RAIDZ).
Instant snapshots/clones for safe upgrades and quick rollback.
Transparent compression (e.g., lz4) often saves space and improves I/O.
Send/receive for fast, incremental backups and replication.

This post uses guided single-disk ZFS via Autoinstall. For mirrors/RAIDZ, use a custom curtin storage stanza.

Minimal Nginx Changes (showing only the two routes)

    # /{b|z}/{ID}/user-data  (SSI expands hostname from named capture)
    location ~ ^/(?&lt;seed>b|z)/(?&lt;host_id>[A-Za-z0-9._-]+)/user-data$ {
        default_type text/plain;
        ssi on; ssi_types *;
        try_files /$seed/_user.ssi =404;
        add_header Cache-Control "no-store";
    }

    # /{b|z}/{ID}/meta-data  (shared block for all seeds)
    location ~ ^/(?&lt;seed>b|z)/(?&lt;host_id>[A-Za-z0-9._-]+)/meta-data$ {
        default_type text/plain;
        ssi on; ssi_types *;
        try_files /$seed/_meta.ssi =404;
        add_header Cache-Control "no-store";
    }

Directory layout now includes the z/ seed:

/var/www/html/nocloud/
├── b/
│   ├── _meta.ssi
│   └── _user.ssi
└── z/
    ├── _meta.ssi
    └── _user.ssi

z/_meta.ssi (minimal)

instance-id: &lt;!--# echo var="host_id" -->

z/_user.ssi (ZFS Autoinstall user-data)

Same structure as before; the functional change is storage.layout: name: zfs with match: { size: largest }.
Still using SSI to inject <ID> into hostname.

#cloud-config
autoinstall:
  version: 1
  identity:
    hostname: &lt;!--# echo var="host_id" -->
    username: ubuntu
    password: "$6$PWguV961aHQjVEUh$EbowTJLSSunVj2zejKxIlS9A6iRBoG8J8XKnTukaTvtyW5QUzK.XQDFv9nEDyBpSpEOmQGMteP5ucnBBI6YsV0"
  timezone: Asia/Taipei
  locale: en_US.UTF-8
  keyboard: { layout: us }
  ssh:
    install-server: true
    allow-pw: true
  apt:
    primary: [{ arches: [default], uri: http://archive.ubuntu.com/ubuntu/ }]
  storage:
    layout:
      name: zfs
      match: { size: largest }
  user-data:
    preserve_hostname: false
    package_update: true
    packages: [htop]
    runcmd:
      - [bash, -lc, "lsb_release -a || true"]
      - [bash, -lc, "lsblk -f"]

GRUB Kernel Argument

At the installer’s GRUB screen, press e and append (replace <ID>):

autoinstall ds="nocloud-net;s=https://nocloud.maksonlee.com/z/&lt;ID>/"

Example:

autoinstall ds="nocloud-net;s=https://nocloud.maksonlee.com/z/zfstest/"

Preflight Checks

# meta-data (should render instance-id: zfstest)
curl -s https://nocloud.maksonlee.com/z/zfstest/meta-data

# user-data (hostname should render as zfstest)
curl -s https://nocloud.maksonlee.com/z/zfstest/user-data

Verify ZFS Root After Installation

zpool list
zpool status
zfs list
mount | grep zfs

You should see rpool and ZFS datasets mounted at /.

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