VIRTUALIZATION.md: storage decision revised — a Disk location picker, plain files on grid's root disk

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

VIRTUALIZATION.md

@@ -1,20 +1,17 @@
 # Virtualization tab — plan (2026-10-09; phase 1 built the same day)
 
-**Status:** phases 1 and 2 are **deployed to all five machines as v0.1.0-188** (2026-10-09).
+**Status:** phases 1 and 2 are **deployed to all five machines as v0.1.0-196** (2026-10-11).
-Incus runs on `grid` (installed from the tab); the other machines show Install or, on `gate`,
+Incus runs on `grid` with **plain-files storage on its root disk** (`local`, see decision 1,
-unavailable. Phase 2 verified live on `grid` through the hub: ISO fetched by URL with its
+revised 2026-10-11 — the file-backed ZFS pool and the test VM are gone); the other machines
-sha256 checked, **New VM from ISO** booted Alpine with Secure Boot off, **the VGA console
+show Install or, on `gate`, unavailable. A **Disk location** picker is on both create forms,
-drew it in a real browser** (headless Chromium, 1280×800 canvas, keyboard and mouse live),
+with add/remove of locations. Phase 2 verified live on `grid` through the hub on 2026-10-09:
-a virtiofs mount appeared in a running VM, an export tarball landed in `virt/exports/` and the
+ISO fetched by URL with its sha256 checked, New VM from ISO booted Alpine with Secure Boot
-nightly cron line is written, `instance.*` sensors flow and the "VM or container down" alert
+off, the VGA console drew it in a real browser (headless Chromium; needed the `binary`
-default is in. Two things found and fixed on the way: spice-html5 wants the `binary`
+websocket subprotocol and one console operation per VM with a data websocket per SPICE
-websocket subprotocol agreed; and it opens one websocket per SPICE channel, so the bridge
+channel), a virtiofs mount appeared in a running VM, an export tarball landed and the nightly
-holds **one console operation per VM** and gives each channel its own data websocket on it
+cron line is written, `instance.*` sensors flow and the "VM or container down" alert default
-(Incus refuses a second operation as "already connected"). **Left from phase 2:** the LAN
+is in. **Left:** the LAN bridge step (his call, needs him near the NanoKVM), cloud-init
-bridge step (`br0` on the uplink — needs a live test on a machine that can afford to drop
+presets beyond "Use my SSH keys", a backup line for `grid`'s `virt/exports/`.
-off the network for a moment, which is a decision, not a build), cloud-init presets beyond
-"Use my SSH keys", and a backup line for `grid`'s `virt/exports/` (see `hamlet/docs/backups.md`).
-`t-alpine` on `grid` is the live example; delete it from the tab when done.
 
 A tab for creating, watching, consoling into and deleting **LXC containers and KVM virtual
 machines**, the way Proxmox does with `pct` and `qm` — **per machine, like every other
@@ -236,12 +233,18 @@ like everything else.
 
 ## Layout decisions Ham Lab makes per machine (overridable in the Install dialog)
 
-1. **Storage.** The instance pool's backing lives in Ham Lab's folder: Install creates a
+1. **Storage — revised 2026-10-11.** The create forms carry a **Disk location** picker: a
-   sparse `virt/pool.img` and hands it to Incus as the pool's `source` (zfs or btrfs by the
+   list of the machine's Incus storage pools, each described by where its bytes land, with
-   detection above), or `virt/pool/` as a `dir` pool where neither is available. Sized from
+   "+ add a location" (any folder on the machine becomes a plain-files pool). On `grid` the
-   the disk's free space, shown and editable. Bulk data is **bind-mounted in**, not stored in
+   one location is `local`: plain files under `virt/pool/` on the root NVMe, each VM's disk
-   the pool. The driver, path and size are recorded in `virt.json` so the page can say where
+   its own sparse file sized on its own, each container a directory, nothing pre-sized.
-   the data is and Install can rebuild the pool from the file after a reinstall.
+   *The first design* (a ZFS pool inside one sparse file, handed to Incus as the pool's
+   source, for instant snapshots and clones) was built, ran for two days, and was taken out
+   at Mitchell's instruction: one pre-sized file holding every disk is an opaque middle
+   layer with a number on it that reads as a reservation, and "zfs · hamlab-virt" on the page
+   read as the NAS pool. The Install dialog still offers zfs/btrfs-in-a-file for a machine
+   that wants instant snapshots; the labels now say exactly what each is. Bulk data is still
+   **bind-mounted in**, not stored in the pool.
 2. **Bridge subnet, computed.** Incus's `auto` picks a random `10.x.y.0/24`, and **this
    LAN is `10.0.0.0/8`** — every host has a /8 on its NIC, so any 10.x bridge collides.
    Ham Lab reads the machine's routes and picks the first free /24 from `192.168.0.0/16`,

internal/api/server.go

@@ -259,6 +259,8 @@ func (s *Server) routes() *http.ServeMux {
 	m.HandleFunc("POST /api/virt/exports/run", s.auth(s.virtExportsRun))
 	m.HandleFunc("POST /api/virt/exports/delete", s.auth(s.virtExportDelete))
 	m.HandleFunc("GET /api/virt/sshkeys", s.auth(s.virtSSHKeys))
+	m.HandleFunc("POST /api/virt/pools", s.auth(s.virtPoolCreate))
+	m.HandleFunc("POST /api/virt/pools/delete", s.auth(s.virtPoolDelete))
 	m.HandleFunc("GET /api/alerts", s.auth(s.alertsGet))
 	m.HandleFunc("PUT /api/alerts", s.auth(s.alertsPut))
 	m.HandleFunc("POST /api/alerts/test", s.auth(s.alertsTest))

internal/api/virt.go

@@ -48,6 +48,7 @@ func (s *Server) virtOverview(w http.ResponseWriter, r *http.Request) {
 		imgs, _ := s.virt.Images(ctx)
 		out["images"] = imgs
 		out["pools"] = s.virt.Pools(ctx)
+		out["default_pool"] = s.virt.DefaultPool(ctx)
 		out["networks"] = s.virt.Networks(ctx)
 	}
 	isos := s.virt.Library(s.virt.ISOsDir())
@@ -1094,3 +1095,70 @@ func (s *Server) virtSSHKeys(w http.ResponseWriter, _ *http.Request) {
 	}
 	jsonOK(w, 200, map[string]any{"keys": keys, "user": s.user})
 }
+
+// ---- locations: storage pools, added as plain-files pools at a path of his choosing ----
+
+func (s *Server) virtPoolCreate(w http.ResponseWriter, r *http.Request) {
+	var body struct {
+		Name string `json:"name"`
+		Path string `json:"path"`
+	}
+	_ = readBody(r, &body, 8192)
+	p := filepath.Clean(body.Path)
+	name := strings.TrimSpace(body.Name)
+	if name == "" {
+		name = sensors.Seg(filepath.Base(p))
+	}
+	if !incus.ValidName(name) {
+		jsonErr(w, 400, "name: letters, digits and dashes, starting with a letter")
+		return
+	}
+	if !filepath.IsAbs(p) || p == "/" {
+		jsonErr(w, 400, "path: an absolute path to a folder on this machine")
+		return
+	}
+	if !s.virtReady(w, r) {
+		return
+	}
+	ctx, cancel := context.WithTimeout(r.Context(), 2*time.Minute)
+	defer cancel()
+	if st, err := os.Stat(p); err == nil && !st.IsDir() {
+		jsonErr(w, 400, p+" is a file, not a folder")
+		return
+	} else if err != nil {
+		mk := priv.Wrap("mkdir", "-p", p) // Incus wants the folder there; it fills it as root
+		if out, err := exec.CommandContext(ctx, mk[0], mk[1:]...).CombinedOutput(); err != nil {
+			jsonErr(w, 500, "could not make "+p+": "+strings.TrimSpace(string(out)))
+			return
+		}
+	}
+	if out, err := s.virt.Cmd(ctx, "storage", "create", name, "dir", "source="+p).CombinedOutput(); err != nil {
+		jsonErr(w, 409, strings.TrimPrefix(strings.TrimSpace(string(out)), "Error: "))
+		return
+	}
+	log.Printf("virt: location %s added at %s (from %s)", name, p, clientIP(r))
+	jsonOK(w, 200, map[string]string{"name": name, "path": p})
+}
+
+func (s *Server) virtPoolDelete(w http.ResponseWriter, r *http.Request) {
+	var body struct {
+		Name string `json:"name"`
+	}
+	_ = readBody(r, &body, 4096)
+	if !incus.ValidName(body.Name) {
+		jsonErr(w, 400, "bad name")
+		return
+	}
+	if !s.virtReady(w, r) {
+		return
+	}
+	ctx, cancel := context.WithTimeout(r.Context(), 2*time.Minute)
+	defer cancel()
+	// Incus refuses a pool anything still uses; that refusal is the answer
+	if out, err := s.virt.Cmd(ctx, "storage", "delete", body.Name).CombinedOutput(); err != nil {
+		jsonErr(w, 409, strings.TrimPrefix(strings.TrimSpace(string(out)), "Error: "))
+		return
+	}
+	log.Printf("virt: location %s removed (from %s)", body.Name, clientIP(r))
+	w.WriteHeader(204)
+}

internal/incus/incus.go

@@ -28,7 +28,7 @@ import (
 )
 
 const (
-	PoolName   = "default"
+	PoolName   = "local" // plain files on the machine's own disk, in Ham Lab's folder
 	BridgeName = "incusbr0"
 	ZPoolName  = "hamlab-virt" // the ZFS pool made on the backing file; Incus is handed it by name
 	AdminGroup = "incus-admin"
@@ -615,11 +615,38 @@ type Pool struct {
 	Name   string `json:"name"`
 	Driver string `json:"driver"`
 	Source string `json:"source"`
+	Where  string `json:"where"` // in words: what disk this is, so a pool is picked by place, not by driver
 	Used   uint64 `json:"used"`
 	Total  uint64 `json:"total"`
 	UsedBy int    `json:"used_by"`
 }
 
+// poolWhere describes a pool by where its bytes land.
+func (m *Manager) poolWhere(driver, source string) string {
+	inHam := strings.HasPrefix(source, m.dir+"/") || source == m.dir
+	switch driver {
+	case "dir":
+		if inHam {
+			return "this machine's own disk — plain files, each disk sized on its own"
+		}
+		return "plain files at " + source
+	case "zfs":
+		if strings.HasSuffix(source, ".img") || source == ZPoolName {
+			return "a ZFS pool inside one file on this machine's disk"
+		}
+		if strings.Contains(source, "/") {
+			return "ZFS dataset " + source
+		}
+		return "ZFS pool " + source
+	case "btrfs":
+		if inHam {
+			return "btrfs inside one file on this machine's disk"
+		}
+		return "btrfs at " + source
+	}
+	return driver + " at " + source
+}
+
 type Network struct {
 	Name    string `json:"name"`
 	Type    string `json:"type"`
@@ -647,7 +674,7 @@ func (m *Manager) Pools(ctx context.Context) []Pool {
 	}
 	var out2 []Pool
 	for _, p := range raw {
-		pool := Pool{Name: p.Name, Driver: p.Driver, Source: p.Config["source"], UsedBy: len(p.UsedBy)}
+		pool := Pool{Name: p.Name, Driver: p.Driver, Source: p.Config["source"], Where: m.poolWhere(p.Driver, p.Config["source"]), UsedBy: len(p.UsedBy)}
 		if b, err := m.run(c, "query", "/1.0/storage-pools/"+p.Name+"/resources"); err == nil {
 			var res struct {
 				Space struct {
@@ -664,6 +691,24 @@ func (m *Manager) Pools(ctx context.Context) []Pool {
 	return out2
 }
 
+// DefaultPool is where a new instance's disk goes unless the form says otherwise: the pool
+// on the default profile's root device.
+func (m *Manager) DefaultPool(ctx context.Context) string {
+	c, cancel := context.WithTimeout(ctx, 10*time.Second)
+	defer cancel()
+	out, err := m.run(c, "query", "/1.0/profiles/default")
+	if err != nil {
+		return ""
+	}
+	var p struct {
+		Devices map[string]map[string]string `json:"devices"`
+	}
+	if json.Unmarshal(out, &p) != nil {
+		return ""
+	}
+	return p.Devices["root"]["pool"]
+}
+
 func (m *Manager) Networks(ctx context.Context) []Network {
 	c, cancel := context.WithTimeout(ctx, 20*time.Second)
 	defer cancel()
@@ -869,6 +914,7 @@ type CreateSpec struct {
 	CPU         string   `json:"cpu"`
 	Memory      string   `json:"memory"`
 	Disk        string   `json:"disk"`
+	Pool        string   `json:"pool"` // where the root disk goes; blank is the default profile's
 	Network     string   `json:"network"`
 	CloudInit   string   `json:"cloud_init"`
 	Profiles    []string `json:"profiles"`
@@ -891,6 +937,8 @@ func CreateArgs(sp CreateSpec, kvm bool) ([]string, error) {
 		return nil, errors.New("memory: a size, like 2GiB")
 	case !ValidSize(sp.Disk):
 		return nil, errors.New("disk: a size, like 20GiB")
+	case sp.Pool != "" && !ValidName(sp.Pool):
+		return nil, errors.New("pool: a storage pool's name")
 	case !ValidNetwork(sp.Network):
 		return nil, errors.New("network: a bridge name")
 	case len(sp.CloudInit) > 256<<10:
@@ -912,8 +960,16 @@ func CreateArgs(sp CreateSpec, kvm bool) ([]string, error) {
 	if sp.Memory != "" {
 		args = append(args, "-c", "limits.memory="+sp.Memory)
 	}
+	// the root disk: the profile's, with the pool and size overridden where given
+	var root []string
+	if sp.Pool != "" {
+		root = append(root, "pool="+sp.Pool)
+	}
 	if sp.Disk != "" {
-		args = append(args, "-d", "root,size="+sp.Disk)
+		root = append(root, "size="+sp.Disk)
+	}
+	if len(root) > 0 {
+		args = append(args, "-d", "root,"+strings.Join(root, ","))
 	}
 	if sp.Network != "" {
 		args = append(args, "-n", sp.Network)
@@ -1104,6 +1160,7 @@ type FromISOSpec struct {
 	CPU        string `json:"cpu"`
 	Memory     string `json:"memory"`
 	Disk       string `json:"disk"`
+	Pool       string `json:"pool"`
 	Network    string `json:"network"`
 	SecureBoot bool   `json:"secureboot"`
 	Start      bool   `json:"start"`
@@ -1121,6 +1178,8 @@ func FromISOScript(sp FromISOSpec, kvm bool) (script string, params []string, er
 		return "", nil, errors.New("iso: pick one from the library")
 	case !ValidCPU(sp.CPU) || !ValidSize(sp.Memory) || !ValidSize(sp.Disk) || !ValidNetwork(sp.Network):
 		return "", nil, errors.New("cpu, memory, disk: a count and two sizes, like 2, 2GiB, 20GiB")
+	case sp.Pool != "" && !ValidName(sp.Pool):
+		return "", nil, errors.New("pool: a storage pool's name")
 	}
 	cpu, mem, disk := sp.CPU, sp.Memory, sp.Disk
 	if cpu == "" {
@@ -1140,13 +1199,14 @@ func FromISOScript(sp FromISOSpec, kvm bool) (script string, params []string, er
 	if sp.Start {
 		start = "1"
 	}
-	// $1 name $2 iso path $3 cpu $4 memory $5 disk $6 network $7 secureboot $8 start
+	// $1 name $2 iso path $3 cpu $4 memory $5 disk $6 network $7 secureboot $8 start $9 pool
 	script = `set -e
 NET=""; [ -n "$6" ] && NET="-n $6"
-incus init --empty --vm "$1" -c limits.cpu="$3" -c limits.memory="$4" -c security.secureboot="$7" -d root,size="$5" $NET
+ROOT="root,size=$5"; [ -n "$9" ] && ROOT="root,pool=$9,size=$5"
+incus init --empty --vm "$1" -c limits.cpu="$3" -c limits.memory="$4" -c security.secureboot="$7" -d "$ROOT" $NET
 incus config device add "$1" iso0 disk source="$2" boot.priority=10
 echo "made $1 with $2 as its first boot device"
 [ "$8" = 1 ] && incus start "$1" && echo "started; open the VGA console to run the installer"
 exit 0`
-	return script, []string{sp.Name, sp.ISO, cpu, mem, disk, sp.Network, sb, start}, nil
+	return script, []string{sp.Name, sp.ISO, cpu, mem, disk, sp.Network, sb, start, sp.Pool}, nil
 }

internal/incus/install_test.go

@@ -21,13 +21,13 @@ func TestInstallScriptShapes(t *testing.T) {
 	}{
 		{"grid: zfs, apt, docker", Status{State: "installable", PM: "apt", Arch: "x86_64", Drivers: []string{"zfs", "btrfs", "dir"}, Docker: true, ZFSHost: true, DiskFree: 700 << 30, MemTotal: 62 << 30},
 			InstallOpts{Driver: "zfs", PoolSizeGiB: 300, Subnet: "172.16.100.1/24", DockerRules: true, ARCMaxGiB: 16},
-			[]string{"apt-get", "zpool create", "incus storage create default zfs source=hamlab-virt", "ipv4.address='172.16.100.1/24'", "DOCKER-USER", "zfs_arc_max", "usermod -aG incus-admin 'core'", "SupplementaryGroups=incus-admin", "systemd-run"}},
+			[]string{"apt-get", "zpool create", "incus storage create local zfs source=hamlab-virt", "ipv4.address='172.16.100.1/24'", "DOCKER-USER", "zfs_arc_max", "usermod -aG incus-admin 'core'", "SupplementaryGroups=incus-admin", "systemd-run"}},
 		{"core: btrfs, apt, docker, no tools yet", Status{State: "installable", PM: "apt", Arch: "x86_64", Drivers: []string{"btrfs", "dir"}, Docker: true, DiskFree: 170 << 30, MemTotal: 8 << 30},
 			InstallOpts{Driver: "btrfs", PoolSizeGiB: 40, Subnet: "172.16.100.1/24", DockerRules: true},
-			[]string{"btrfs-progs", "mkfs.btrfs", "/etc/fstab", "incus storage create default btrfs source="}},
+			[]string{"btrfs-progs", "mkfs.btrfs", "/etc/fstab", "incus storage create local btrfs source="}},
 		{"mac: dir, dnf, arm64", Status{State: "installable", PM: "dnf", Arch: "aarch64", Drivers: []string{"dir"}, DiskFree: 200 << 30, MemTotal: 15 << 30},
 			InstallOpts{Driver: "dir", Subnet: "172.16.101.1/24"},
-			[]string{"dnf -y install incus qemu-system-aarch64-core edk2-aarch64", "incus storage create default dir source="}},
+			[]string{"dnf -y install incus qemu-system-aarch64-core edk2-aarch64", "incus storage create local dir source="}},
 		{"repair: already installed", Status{State: "repair", PM: "apt", Arch: "x86_64", Drivers: []string{"dir"}, DiskFree: 10 << 30, MemTotal: 4 << 30},
 			InstallOpts{Driver: "dir", Subnet: "172.16.100.1/24"},
 			[]string{"already installed"}},
@@ -75,6 +75,9 @@ func TestCreateArgs(t *testing.T) {
 		t.Fatal(err)
 	}
 	want := "launch images:debian/13 web-1 --vm -c limits.cpu=2 -c limits.memory=2GiB -d root,size=20GiB -n incusbr0"
+	if a, err := CreateArgs(CreateSpec{Name: "x", Image: "images:alpine/3.22", Pool: "local"}, true); err != nil || strings.Join(a, " ") != "init images:alpine/3.22 x -d root,pool=local" {
+		t.Fatalf("pool override: %v %v", a, err)
+	}
 	if got := strings.Join(args, " "); got != want {
 		t.Fatalf("got %q", got)
 	}

internal/storage/snapshots.go

@@ -66,7 +66,6 @@ type Policy struct {
 	KeepMin int    `json:"keep_min"`
 	Prefix  string `json:"prefix"`
 	Enabled bool   `json:"enabled"`
-
 }
 
 func (p *Policy) prefix() string { return strings.TrimSpace(p.Prefix) }

internal/storage/snapshots_test.go

@@ -106,8 +106,8 @@ func TestValidateRefusesNonsense(t *testing.T) {
 		{Dataset: "tank", Every: "custom", KeepFor: "6w"},
 		{Dataset: "tank", Every: "custom", Cron: "not a schedule", KeepFor: "6w"},
 		{Dataset: "tank", Every: "daily", At: "25:00", KeepFor: "6w"},
-		{Dataset: "tank", Every: "daily", At: "02:30"},                          // no retention
+		{Dataset: "tank", Every: "daily", At: "02:30"},                           // no retention
-		{Dataset: "tank", Every: "daily", At: "02:30", KeepFor: "6 weeks"},      // unparseable
+		{Dataset: "tank", Every: "daily", At: "02:30", KeepFor: "6 weeks"},       // unparseable
 		{Dataset: "tank", Every: "monthly", At: "02:30", Day: 31, KeepFor: "6w"}, // not every month has one
 		{Dataset: "tank", Every: "daily", At: "02:30", KeepFor: "6w", Prefix: "a--b"},
 	}

web/src/Virtualization.tsx

@@ -81,7 +81,7 @@ export default function Virtualization() {
         {tab === 'images' && <Images st={st} images={images} instances={instances} onTask={startTask} onNew={(image, vm) => { setTab('instances'); setMaking({ image, vm }) }} onChanged={load} />}
         {tab === 'library' && <Library st={st} ov={ov} onTask={startTask} onChanged={load} onNewVM={(iso) => setFromIso(iso)} />}
       </div>
-      {tab === 'instances' && (cur ? <Detail i={cur} st={st} onBack={() => setSel('')} onChanged={load} onTask={startTask} /> : <Summary ov={ov} />)}
+      {tab === 'instances' && (cur ? <Detail i={cur} st={st} onBack={() => setSel('')} onChanged={load} onTask={startTask} /> : <Summary ov={ov} onChanged={load} />)}
       {making && <NewInstance st={st} ov={ov} preset={making} onClose={() => setMaking(null)} onStarted={(t) => { setMaking(null); startTask(t) }} />}
       {fromIso !== null && <NewVMFromISO st={st} ov={ov} iso={fromIso} onClose={() => setFromIso(null)} onStarted={(t) => { setFromIso(null); startTask(t); setTab('instances') }} />}
     </div>
@@ -151,11 +151,11 @@ function InstallDialog({ st, onClose, onStarted }: { st: VirtStatus; onClose: ()
         <div className="notice">Everything goes under <span className="mono">{st.dir}</span>: the pool's backing file, ISOs, images, exports. Where is not a choice; how big is.</div>
         <label className="muted">Pool driver
           <select value={driver} onChange={(e) => setDriver(e.target.value)}>
-            {st.drivers.map((d) => <option key={d} value={d}>{d}{d === 'zfs' ? ' — snapshots and clones are instant' : d === 'btrfs' ? ' — snapshots, on a loop file' : ' — plain files, no snapshots to speak of'}</option>)}
+            {st.drivers.map((d) => <option key={d} value={d}>{d === 'dir' ? 'plain files on this disk — each VM\u2019s disk is its own file, sized on its own; snapshots are copies' : d === 'zfs' ? 'zfs — one pre-sized file holding every disk; snapshots and clones are instant' : 'btrfs — one pre-sized file holding every disk; snapshots are instant'}</option>)}
           </select>
         </label>
         {driver !== 'dir' && (
-          <label className="muted">Pool size, GiB — a sparse file, grows as used · {fmtBytes(st.disk_free)} free
+          <label className="muted">Ceiling of that file, GiB — sparse, it grows only as disks fill it · {fmtBytes(st.disk_free)} free
             <input type="number" min={5} max={Math.floor(st.disk_free / GiB)} value={size} onChange={(e) => setSize(e.target.value)} required />
           </label>
         )}
@@ -187,7 +187,17 @@ function InstallDialog({ st, onClose, onStarted }: { st: VirtStatus; onClose: ()
 
 // ---- the right-hand pane when nothing is selected: what this machine's Incus is ----
 
-function Summary({ ov }: { ov: VirtOverview }) {
+// A location is a plain-files storage pool at a folder of his choosing.
+async function addLocation(onDone: (name: string) => void) {
+  const path = await askText('Folder on this machine for instance disks', '/', 'Next')
+  if (!path) return
+  const base = path.split('/').filter(Boolean).pop() ?? 'disks'
+  const name = await askText(`A name for ${path}`, base.toLowerCase().replace(/[^a-z0-9-]+/g, '-').replace(/^-|-$/g, ''), 'Add')
+  if (!name) return
+  try { const r = await api.virtPoolCreate(name, path); toast(`${r.name} added at ${r.path}`); onDone(r.name) } catch (e) { toast(errMsg(e), 'err') }
+}
+
+function Summary({ ov, onChanged }: { ov: VirtOverview; onChanged: () => void }) {
   const st = ov.status
   return (
     <div className="svc-detail">
@@ -198,9 +208,11 @@ function Summary({ ov }: { ov: VirtOverview }) {
         {st.layout && <div><span className="k">Installed</span><span>{when(st.layout.attempted)} by Ham Lab {st.layout.hamlab_version ?? ''}</span></div>}
         {!st.layout && <div><span className="k">Installed</span><span>outside Ham Lab — pools and networks below are as found</span></div>}
       </div>
-      <h3 className="stack-head">Storage pools</h3>
+      <h3 className="stack-head">Disk locations <span className="muted">· where an instance\u2019s disk can go</span></h3>
-      <table className="virt-table"><thead><tr><th>Pool</th><th>Driver</th><th>Source</th><th className="num">Used</th><th className="num">Of</th><th className="num">Users</th></tr></thead>
+      <table className="virt-table"><thead><tr><th>Location</th><th>Where</th><th className="num">Used</th><th className="num">Free</th><th className="num">Disks</th><th /></tr></thead>
-        <tbody>{(ov.pools ?? []).map((p) => <tr key={p.name}><td>{p.name}</td><td>{p.driver}</td><td className="mono small">{p.source}</td><td className="num">{p.total ? fmtBytes(p.used) : '—'}</td><td className="num">{p.total ? fmtBytes(p.total) : '—'}</td><td className="num">{p.used_by}</td></tr>)}</tbody></table>
+        <tbody>{(ov.pools ?? []).map((p) => <tr key={p.name}><td>{p.name}{p.name === ov.default_pool && <span className="badge">default</span>}</td><td>{p.where}<div className="muted small mono">{p.driver} · {p.source}</div></td><td className="num">{p.total ? fmtBytes(p.used) : '—'}</td><td className="num">{p.total ? fmtBytes(p.total - p.used) : '—'}</td><td className="num">{p.used_by}</td>
+          <td className="num">{p.used_by === 0 && p.name !== ov.default_pool && <Btn className="btn danger" confirm={`Remove the location ${p.name}? Nothing uses it; the folder itself is left alone.`} onClick={async () => { try { await api.virtPoolDelete(p.name); toast('removed'); onChanged() } catch (e) { toast(errMsg(e), 'err') } }}>Remove</Btn>}</td></tr>)}</tbody></table>
+      <div className="svc-actions"><Btn className="btn" onClick={() => addLocation(onChanged)}>+ Add a location…</Btn><span className="muted small">a folder on this machine; VM disks become files in it, containers folders</span></div>
       <h3 className="stack-head">Networks</h3>
       <table className="virt-table"><thead><tr><th>Network</th><th>Type</th><th>Address</th><th>NAT</th><th className="num">Users</th></tr></thead>
         <tbody>{(ov.networks ?? []).filter((n) => n.managed).map((n) => <tr key={n.name}><td>{n.name}</td><td>{n.type}</td><td className="mono small">{n.address ?? '—'}</td><td>{n.nat ? 'yes' : 'no'}</td><td className="num">{n.used_by}</td></tr>)}</tbody></table>
@@ -248,7 +260,7 @@ function Detail({ i, st, onBack, onChanged, onTask }: { i: VirtInstance; st: Vir
         {i.description && <div><span className="k">About</span><span>{i.description}</span></div>}
         {running && <div><span className="k">Using</span><span>{i.cpu_pct.toFixed(0)}% of a core · {fmtBytes(i.mem_usage)}{i.mem_peak ? ` (peak ${fmtBytes(i.mem_peak)})` : ''}{i.processes > 0 ? ` · ${i.processes} processes` : ''}</span></div>}
         <div><span className="k">Limits</span><span>{i.cpu ? `${i.cpu} CPU` : 'all CPUs'} · {i.memory || 'unlimited memory'}</span></div>
-        {i.disk_total > 0 && <div><span className="k">Disk</span><span>{fmtBytes(i.disk_usage)} of {fmtBytes(i.disk_total)}</span></div>}
+        <div><span className="k">Disk</span><span>{i.disk_total > 0 ? `${fmtBytes(i.disk_usage)} of ${fmtBytes(i.disk_total)}` : i.disk_usage > 0 ? fmtBytes(i.disk_usage) : 'no limit'}{i.devices.root?.pool ? <span className="muted"> · on {i.devices.root.pool}</span> : ''}</span></div>
         <div><span className="k">Network</span><span className="mono small">{i.ipv4.length ? i.ipv4.join('  ') : running ? 'no address yet' : '—'}</span></div>
         <div><span className="k">Created</span><span>{when(i.created)}</span></div>
       </div>
@@ -348,6 +360,20 @@ function Snapshots({ i, onChanged }: { i: VirtInstance; onChanged: () => void })
 
 // ---- making one ----
 
+// Where an instance's disk goes. One entry is still a choice shown; a new one can be added here.
+function PoolPick({ ov, value, onChange }: { ov: VirtOverview; value: string; onChange: (v: string) => void }) {
+  const [extra, setExtra] = useState<{ name: string; where: string }[]>([])
+  const pools = [...(ov.pools ?? []).map((p) => ({ name: p.name, where: p.where + (p.total ? ` · ${fmtBytes(p.total - p.used)} free` : '') })), ...extra.filter((e) => !(ov.pools ?? []).some((p) => p.name === e.name))]
+  return (
+    <label className="muted">Disk location
+      <select value={value} onChange={(e) => { if (e.target.value === '+') addLocation((n) => { setExtra((x) => [...x, { name: n, where: 'just added' }]); onChange(n) }); else onChange(e.target.value) }}>
+        {pools.map((p) => <option key={p.name} value={p.name}>{p.name} — {p.where}</option>)}
+        <option value="+">+ add a location…</option>
+      </select>
+    </label>
+  )
+}
+
 function NewInstance({ st, ov, preset, onClose, onStarted }: { st: VirtStatus; ov: VirtOverview; preset: { image?: string; vm?: boolean }; onClose: () => void; onStarted: (t: TaskInfo) => void }) {
   const [vm, setVm] = useState(!!preset.vm && st.kvm)
   const [image, setImage] = useState(preset.image ?? '')
@@ -355,6 +381,7 @@ function NewInstance({ st, ov, preset, onClose, onStarted }: { st: VirtStatus; o
   const [cpu, setCpu] = useState('')
   const [mem, setMem] = useState('')
   const [disk, setDisk] = useState('')
+  const [pool, setPool] = useState(ov.default_pool || ov.pools?.[0]?.name || '')
   const nets = (ov.networks ?? []).filter((n) => n.managed || n.type === 'bridge')
   const [net, setNet] = useState(nets.find((n) => n.name === 'incusbr0')?.name ?? nets[0]?.name ?? '')
   const [cloud, setCloud] = useState('')
@@ -387,7 +414,7 @@ function NewInstance({ st, ov, preset, onClose, onStarted }: { st: VirtStatus; o
   }, [q, local, remote])
   const submit = async (e: FormEvent) => {
     e.preventDefault(); setErr(''); setBusy(true)
-    try { onStarted(await api.virtCreate({ name: name.trim(), image: image.trim(), vm, cpu: cpu.trim(), memory: mem.trim(), disk: disk.trim(), network: net, cloud_init: showCloud ? cloud : '', profiles: [], description: desc.trim(), start })) }
+    try { onStarted(await api.virtCreate({ name: name.trim(), image: image.trim(), vm, cpu: cpu.trim(), memory: mem.trim(), disk: disk.trim(), pool, network: net, cloud_init: showCloud ? cloud : '', profiles: [], description: desc.trim(), start })) }
     catch (e) { setErr(errMsg(e)); setBusy(false) }
   }
   return (
@@ -418,8 +445,9 @@ function NewInstance({ st, ov, preset, onClose, onStarted }: { st: VirtStatus; o
         <div className="virt-form-row">
           <label className="muted">CPUs<input className="mono" value={cpu} onChange={(e) => setCpu(e.target.value)} placeholder={vm ? '2' : 'all'} /></label>
           <label className="muted">Memory<input className="mono" value={mem} onChange={(e) => setMem(e.target.value)} placeholder={vm ? '2GiB' : 'unlimited'} /></label>
-          <label className="muted">Root disk<input className="mono" value={disk} onChange={(e) => setDisk(e.target.value)} placeholder={vm ? '20GiB' : 'pool default'} /></label>
+          <label className="muted">Root disk<input className="mono" value={disk} onChange={(e) => setDisk(e.target.value)} placeholder={vm ? '20GiB' : 'no limit'} /></label>
         </div>
+        <PoolPick ov={ov} value={pool} onChange={setPool} />
         <div className="muted small">{fmtBytes(st.mem_avail)} free on this machine.{vm ? ' A VM’s memory is a reservation.' : ''}</div>
         <label className="muted">Description — optional<input value={desc} onChange={(e) => setDesc(e.target.value)} maxLength={200} /></label>
         <label className="muted" style={{ flexDirection: 'row', alignItems: 'center', gap: 8 }}>
@@ -556,6 +584,7 @@ function NewVMFromISO({ st, ov, iso, onClose, onStarted }: { st: VirtStatus; ov:
   const [cpu, setCpu] = useState('2')
   const [mem, setMem] = useState('2GiB')
   const [disk, setDisk] = useState('20GiB')
+  const [pool, setPool] = useState(ov.default_pool || ov.pools?.[0]?.name || '')
   const nets = (ov.networks ?? []).filter((n) => n.managed || n.type === 'bridge')
   const [net, setNet] = useState(nets.find((n) => n.name === 'incusbr0')?.name ?? nets[0]?.name ?? '')
   const [sb, setSb] = useState(true)
@@ -564,7 +593,7 @@ function NewVMFromISO({ st, ov, iso, onClose, onStarted }: { st: VirtStatus; ov:
   useEscape(onClose)
   const submit = async (e: FormEvent) => {
     e.preventDefault(); setErr(''); setBusy(true)
-    try { onStarted(await api.virtFromISO({ name: name.trim(), iso: pick, cpu: cpu.trim(), memory: mem.trim(), disk: disk.trim(), network: net, secureboot: sb, start: true })) }
+    try { onStarted(await api.virtFromISO({ name: name.trim(), iso: pick, cpu: cpu.trim(), memory: mem.trim(), disk: disk.trim(), pool, network: net, secureboot: sb, start: true })) }
     catch (e) { setErr(errMsg(e)); setBusy(false) }
   }
   return (
@@ -581,6 +610,7 @@ function NewVMFromISO({ st, ov, iso, onClose, onStarted }: { st: VirtStatus; ov:
           <label className="muted">Memory<input className="mono" value={mem} onChange={(e) => setMem(e.target.value)} /></label>
           <label className="muted">Disk<input className="mono" value={disk} onChange={(e) => setDisk(e.target.value)} /></label>
         </div>
+        <PoolPick ov={ov} value={pool} onChange={setPool} />
         <label className="muted" style={{ flexDirection: 'row', alignItems: 'center', gap: 8 }}>
           <input type="checkbox" checked={sb} onChange={(e) => setSb(e.target.checked)} style={{ width: 'auto' }} />Secure Boot — Windows, Debian, Ubuntu and Fedora boot with it; Alpine, Arch, TrueNAS and most others need it off
         </label>

web/src/api.ts

@@ -260,17 +260,17 @@ export interface VirtStatus { state: 'ready' | 'repair' | 'installable' | 'unava
 export interface VirtSnapshot { name: string; created: string; expires?: string; size?: number }
 export interface VirtInstance { name: string; type: 'container' | 'virtual-machine'; status: string; arch: string; description?: string; image: string; os?: string; release?: string; cpu?: string; memory?: string; created: string; last_used: string; ipv4: string[]; snapshots: VirtSnapshot[]; profiles: string[]; ephemeral: boolean; cpu_pct: number; mem_usage: number; mem_peak: number; disk_usage: number; disk_total: number; pid: number; processes: number; config: Record<string, string>; devices: Record<string, Record<string, string>>; schedule?: string; expiry?: string }
 export interface VirtImage { fingerprint: string; aliases: string[]; arch: string; type: string; size: number; created: string; last_used: string; description: string; os?: string; release?: string; variant?: string; cached: boolean; source?: string; public: boolean }
-export interface VirtPool { name: string; driver: string; source: string; used: number; total: number; used_by: number }
+export interface VirtPool { name: string; driver: string; source: string; where: string; used: number; total: number; used_by: number }
 export interface VirtNetwork { name: string; type: string; managed: boolean; address?: string; nat: boolean; used_by: number }
 export interface LibraryFile { name: string; size: number; modified: string; attached_to?: string[] }
 export interface ExportConfig { enabled: boolean; hour: number; minute: number; keep: number; instance_only: boolean; instances?: string[]; updated?: string }
 export interface ExportRun { at: string; exported: string[]; pruned: string[]; errors?: string[]; seconds: number }
 export interface ExportFile { instance: string; name: string; size: number; modified: string }
 export interface ExportsView { config: ExportConfig; cron: string; next?: string; last: ExportRun | null; files: ExportFile[]; dir: string; cron_file: string }
-export interface FromISO { name: string; iso: string; cpu: string; memory: string; disk: string; network: string; secureboot: boolean; start: boolean }
+export interface FromISO { name: string; iso: string; cpu: string; memory: string; disk: string; pool: string; network: string; secureboot: boolean; start: boolean }
-export interface VirtOverview { status: VirtStatus; error?: string; instances?: VirtInstance[]; images?: VirtImage[]; pools?: VirtPool[]; networks?: VirtNetwork[]; library: { images: LibraryFile[]; isos: LibraryFile[] } }
+export interface VirtOverview { status: VirtStatus; error?: string; instances?: VirtInstance[]; images?: VirtImage[]; pools?: VirtPool[]; default_pool?: string; networks?: VirtNetwork[]; library: { images: LibraryFile[]; isos: LibraryFile[] } }
 export interface VirtInstallOpts { driver: string; pool_size_gib: number; subnet: string; docker_rules: boolean; arc_max_gib: number }
-export interface VirtCreate { name: string; image: string; vm: boolean; cpu: string; memory: string; disk: string; network: string; cloud_init: string; profiles: string[]; description: string; start: boolean }
+export interface VirtCreate { name: string; image: string; vm: boolean; cpu: string; memory: string; disk: string; pool: string; network: string; cloud_init: string; profiles: string[]; description: string; start: boolean }
 
 export const api = {
   procs: () => req<ProcTable>('GET', '/api/procs'),
@@ -456,6 +456,8 @@ export const api = {
   virtExportsRun: (instance = '') => req<TaskInfo>('POST', '/api/virt/exports/run', { instance }),
   virtExportDelete: (instance: string, name: string) => req<void>('POST', '/api/virt/exports/delete', { instance, name }),
   virtSSHKeys: () => req<{ keys: string[]; user: string }>('GET', '/api/virt/sshkeys'),
+  virtPoolCreate: (name: string, path: string) => req<{ name: string; path: string }>('POST', '/api/virt/pools', { name, path }),
+  virtPoolDelete: (name: string) => req<void>('POST', '/api/virt/pools/delete', { name }),
 }
 
 export function wsURLPath(path: string): string {