feat: simplify snapshot restore to disk boot

internal/daemon/daemon_test.go

@@ -434,11 +434,9 @@ func TestRestoreSnapshotFallsBackToLocalSnapshotNetwork(t *testing.T) {
 	hostDaemon.reconfigureGuestIdentity = func(context.Context, string, contracthost.MachineID, *contracthost.GuestConfig) error { return nil }
 
 	server := newRestoreArtifactServer(t, map[string][]byte{
-		"/kernel":  []byte("kernel"),
+		"/kernel": []byte("kernel"),
-		"/rootfs":  []byte("rootfs"),
+		"/rootfs": []byte("rootfs"),
-		"/memory":  []byte("mem"),
+		"/system": []byte("disk"),
-		"/vmstate": []byte("state"),
-		"/system":  []byte("disk"),
 	})
 	defer server.Close()
 
@@ -465,8 +463,6 @@ func TestRestoreSnapshotFallsBackToLocalSnapshotNetwork(t *testing.T) {
 		ID:                "snap1",
 		MachineID:         "source",
 		Artifact:          artifactRef,
-		MemFilePath:       filepath.Join(root, "snapshots", "snap1", "memory.bin"),
-		StateFilePath:     filepath.Join(root, "snapshots", "snap1", "vmstate.bin"),
 		DiskPaths:         []string{filepath.Join(root, "snapshots", "snap1", "system.img")},
 		SourceRuntimeHost: "172.16.0.2",
 		SourceTapDevice:   "fctap0",
@@ -486,8 +482,6 @@ func TestRestoreSnapshotFallsBackToLocalSnapshotNetwork(t *testing.T) {
 			MachineID:  "source",
 			ImageID:    "image-1",
 			Artifacts: []contracthost.SnapshotArtifact{
-				{ID: "memory", Kind: contracthost.SnapshotArtifactKindMemory, Name: "memory.bin", DownloadURL: server.URL + "/memory"},
-				{ID: "vmstate", Kind: contracthost.SnapshotArtifactKindVMState, Name: "vmstate.bin", DownloadURL: server.URL + "/vmstate"},
 				{ID: "disk-system", Kind: contracthost.SnapshotArtifactKindDisk, Name: "system.img", DownloadURL: server.URL + "/system"},
 			},
 		},
@@ -502,17 +496,11 @@ func TestRestoreSnapshotFallsBackToLocalSnapshotNetwork(t *testing.T) {
 	if response.Machine.Phase != contracthost.MachinePhaseStarting {
 		t.Fatalf("restored machine phase mismatch: got %q", response.Machine.Phase)
 	}
-	if runtime.restoreCalls != 1 {
+	if runtime.bootCalls != 1 {
-		t.Fatalf("restore boot call count mismatch: got %d want 1", runtime.restoreCalls)
+		t.Fatalf("boot call count mismatch: got %d want 1", runtime.bootCalls)
 	}
-	if runtime.lastLoadSpec.Network == nil {
+	if runtime.restoreCalls != 0 {
-		t.Fatalf("restore boot should preserve snapshot network")
+		t.Fatalf("restore boot call count mismatch: got %d want 0", runtime.restoreCalls)
-	}
-	if got := runtime.lastLoadSpec.Network.GuestIP().String(); got != "172.16.0.2" {
-		t.Fatalf("restore guest ip mismatch: got %q want %q", got, "172.16.0.2")
-	}
-	if got := runtime.lastLoadSpec.Network.TapName; got != "fctap0" {
-		t.Fatalf("restore tap mismatch: got %q want %q", got, "fctap0")
 	}
 
 	ops, err := fileStore.ListOperations(context.Background())
@@ -593,28 +581,16 @@ func TestRestoreSnapshotUsesLocalSnapshotArtifacts(t *testing.T) {
 	if err := os.MkdirAll(snapshotDir, 0o755); err != nil {
 		t.Fatalf("create snapshot dir: %v", err)
 	}
-	memoryPath := filepath.Join(snapshotDir, "memory.bin")
-	vmstatePath := filepath.Join(snapshotDir, "vmstate.bin")
 	systemPath := filepath.Join(snapshotDir, "system.img")
-	if err := os.WriteFile(memoryPath, []byte("mem"), 0o644); err != nil {
-		t.Fatalf("write memory: %v", err)
-	}
-	if err := os.WriteFile(vmstatePath, []byte("state"), 0o644); err != nil {
-		t.Fatalf("write vmstate: %v", err)
-	}
 	if err := os.WriteFile(systemPath, []byte("disk"), 0o644); err != nil {
 		t.Fatalf("write system disk: %v", err)
 	}
 	if err := fileStore.CreateSnapshot(context.Background(), model.SnapshotRecord{
-		ID:            "snap-local",
+		ID:        "snap-local",
-		MachineID:     "source",
+		MachineID: "source",
-		Artifact:      artifactRef,
+		Artifact:  artifactRef,
-		MemFilePath:   memoryPath,
+		DiskPaths: []string{systemPath},
-		StateFilePath: vmstatePath,
-		DiskPaths:     []string{systemPath},
 		Artifacts: []model.SnapshotArtifactRecord{
-			{ID: "memory", Kind: contracthost.SnapshotArtifactKindMemory, Name: "memory.bin", LocalPath: memoryPath, SizeBytes: 3},
-			{ID: "vmstate", Kind: contracthost.SnapshotArtifactKindVMState, Name: "vmstate.bin", LocalPath: vmstatePath, SizeBytes: 5},
 			{ID: "disk-system", Kind: contracthost.SnapshotArtifactKindDisk, Name: "system.img", LocalPath: systemPath, SizeBytes: 4},
 		},
 		SourceRuntimeHost: "172.16.0.2",
@@ -638,17 +614,11 @@ func TestRestoreSnapshotUsesLocalSnapshotArtifacts(t *testing.T) {
 	if response.Machine.ID != "restored-local" {
 		t.Fatalf("restored machine id mismatch: got %q", response.Machine.ID)
 	}
-	if runtime.restoreCalls != 1 {
+	if runtime.bootCalls != 1 {
-		t.Fatalf("restore boot call count mismatch: got %d want 1", runtime.restoreCalls)
+		t.Fatalf("boot call count mismatch: got %d want 1", runtime.bootCalls)
 	}
-	if runtime.lastLoadSpec.Network == nil {
+	if runtime.restoreCalls != 0 {
-		t.Fatalf("restore boot should preserve local snapshot network")
+		t.Fatalf("restore boot call count mismatch: got %d want 0", runtime.restoreCalls)
-	}
-	if got := runtime.lastLoadSpec.Network.GuestIP().String(); got != "172.16.0.2" {
-		t.Fatalf("restore guest ip mismatch: got %q want %q", got, "172.16.0.2")
-	}
-	if got := runtime.lastLoadSpec.Network.TapName; got != "fctap0" {
-		t.Fatalf("restore tap mismatch: got %q want %q", got, "fctap0")
 	}
 }
 
@@ -741,12 +711,10 @@ func TestRestoreSnapshotUsesDurableSnapshotSpec(t *testing.T) {
 	}
 
 	server := newRestoreArtifactServer(t, map[string][]byte{
-		"/kernel":  []byte("kernel"),
+		"/kernel": []byte("kernel"),
-		"/rootfs":  []byte("rootfs"),
+		"/rootfs": []byte("rootfs"),
-		"/memory":  []byte("mem"),
+		"/system": []byte("disk"),
-		"/vmstate": []byte("state"),
+		"/user-0": []byte("user-disk"),
-		"/system":  []byte("disk"),
-		"/user-0":  []byte("user-disk"),
 	})
 	defer server.Close()
 
@@ -763,8 +731,6 @@ func TestRestoreSnapshotUsesDurableSnapshotSpec(t *testing.T) {
 			SourceRuntimeHost: "172.16.0.2",
 			SourceTapDevice:   "fctap0",
 			Artifacts: []contracthost.SnapshotArtifact{
-				{ID: "memory", Kind: contracthost.SnapshotArtifactKindMemory, Name: "memory.bin", DownloadURL: server.URL + "/memory"},
-				{ID: "vmstate", Kind: contracthost.SnapshotArtifactKindVMState, Name: "vmstate.bin", DownloadURL: server.URL + "/vmstate"},
 				{ID: "disk-system", Kind: contracthost.SnapshotArtifactKindDisk, Name: "system.img", DownloadURL: server.URL + "/system"},
 				{ID: "disk-user-0", Kind: contracthost.SnapshotArtifactKindDisk, Name: "user-0.img", DownloadURL: server.URL + "/user-0"},
 			},
@@ -780,23 +746,17 @@ func TestRestoreSnapshotUsesDurableSnapshotSpec(t *testing.T) {
 	if response.Machine.Phase != contracthost.MachinePhaseStarting {
 		t.Fatalf("restored machine phase mismatch: got %q", response.Machine.Phase)
 	}
-	if runtime.restoreCalls != 1 {
+	if runtime.bootCalls != 1 {
-		t.Fatalf("restore boot call count mismatch: got %d want 1", runtime.restoreCalls)
+		t.Fatalf("boot call count mismatch: got %d want 1", runtime.bootCalls)
 	}
-	if runtime.lastLoadSpec.Network == nil {
+	if runtime.restoreCalls != 0 {
-		t.Fatalf("restore boot should preserve durable snapshot network")
+		t.Fatalf("restore boot call count mismatch: got %d want 0", runtime.restoreCalls)
 	}
-	if got := runtime.lastLoadSpec.Network.GuestIP().String(); got != "172.16.0.2" {
+	if !strings.Contains(runtime.lastSpec.KernelImagePath, filepath.Join("artifacts", artifactKey(contracthost.ArtifactRef{
-		t.Fatalf("restore guest ip mismatch: got %q want %q", got, "172.16.0.2")
-	}
-	if got := runtime.lastLoadSpec.Network.TapName; got != "fctap0" {
-		t.Fatalf("restore tap mismatch: got %q want %q", got, "fctap0")
-	}
-	if !strings.Contains(runtime.lastLoadSpec.KernelImagePath, filepath.Join("artifacts", artifactKey(contracthost.ArtifactRef{
 		KernelImageURL: server.URL + "/kernel",
 		RootFSURL:      server.URL + "/rootfs",
 	}), "kernel")) {
-		t.Fatalf("restore boot kernel path mismatch: got %q", runtime.lastLoadSpec.KernelImagePath)
+		t.Fatalf("restore boot kernel path mismatch: got %q", runtime.lastSpec.KernelImagePath)
 	}
 
 	machine, err := fileStore.GetMachine(context.Background(), "restored")
@@ -825,7 +785,7 @@ func TestRestoreSnapshotUsesDurableSnapshotSpec(t *testing.T) {
 	}
 }
 
-func TestRestoreSnapshotRejectsWhenRestoreNetworkInUseOnHost(t *testing.T) {
+func TestRestoreSnapshotBootsWithFreshNetworkWhenSourceNetworkInUseOnHost(t *testing.T) {
 	root := t.TempDir()
 	cfg := testConfig(root)
 	fileStore, err := store.NewFileStore(cfg.StatePath, cfg.OperationsPath)
@@ -838,6 +798,31 @@ func TestRestoreSnapshotRejectsWhenRestoreNetworkInUseOnHost(t *testing.T) {
 	if err != nil {
 		t.Fatalf("create daemon: %v", err)
 	}
+	stubGuestSSHPublicKeyReader(hostDaemon)
+	hostDaemon.reconfigureGuestIdentity = func(context.Context, string, contracthost.MachineID, *contracthost.GuestConfig) error { return nil }
+
+	sshListener := listenTestPort(t, int(defaultSSHPort))
+	defer func() { _ = sshListener.Close() }()
+	vncListener := listenTestPort(t, int(defaultVNCPort))
+	defer func() { _ = vncListener.Close() }()
+
+	startedAt := time.Unix(1700000299, 0).UTC()
+	runtime.bootState = firecracker.MachineState{
+		ID:          "restored",
+		Phase:       firecracker.PhaseRunning,
+		PID:         1234,
+		RuntimeHost: "127.0.0.1",
+		SocketPath:  filepath.Join(cfg.RuntimeDir, "machines", "restored", "root", "run", "firecracker.sock"),
+		TapName:     "fctap9",
+		StartedAt:   &startedAt,
+	}
+
+	server := newRestoreArtifactServer(t, map[string][]byte{
+		"/kernel": []byte("kernel"),
+		"/rootfs": []byte("rootfs"),
+		"/system": []byte("disk"),
+	})
+	defer server.Close()
 
 	if err := fileStore.CreateMachine(context.Background(), model.MachineRecord{
 		ID:             "source",
@@ -851,11 +836,11 @@ func TestRestoreSnapshotRejectsWhenRestoreNetworkInUseOnHost(t *testing.T) {
 		t.Fatalf("create running source machine: %v", err)
 	}
 
-	_, err = hostDaemon.RestoreSnapshot(context.Background(), "snap1", contracthost.RestoreSnapshotRequest{
+	response, err := hostDaemon.RestoreSnapshot(context.Background(), "snap1", contracthost.RestoreSnapshotRequest{
 		MachineID: "restored",
 		Artifact: contracthost.ArtifactRef{
-			KernelImageURL: "https://example.com/kernel",
+			KernelImageURL: server.URL + "/kernel",
-			RootFSURL:      "https://example.com/rootfs",
+			RootFSURL:      server.URL + "/rootfs",
 		},
 		Snapshot: &contracthost.DurableSnapshotSpec{
 			SnapshotID:        "snap1",
@@ -863,10 +848,19 @@ func TestRestoreSnapshotRejectsWhenRestoreNetworkInUseOnHost(t *testing.T) {
 			ImageID:           "image-1",
 			SourceRuntimeHost: "172.16.0.2",
 			SourceTapDevice:   "fctap0",
+			Artifacts: []contracthost.SnapshotArtifact{
+				{ID: "disk-system", Kind: contracthost.SnapshotArtifactKindDisk, Name: "system.img", DownloadURL: server.URL + "/system"},
+			},
 		},
 	})
-	if err == nil || !strings.Contains(err.Error(), "still in use on this host") {
+	if err != nil {
-		t.Fatalf("restore snapshot error = %v, want restore network in-use failure", err)
+		t.Fatalf("restore snapshot error = %v, want success", err)
+	}
+	if response.Machine.Phase != contracthost.MachinePhaseStarting {
+		t.Fatalf("restored machine phase mismatch: got %q", response.Machine.Phase)
+	}
+	if runtime.bootCalls != 1 {
+		t.Fatalf("boot call count mismatch: got %d want 1", runtime.bootCalls)
 	}
 	if runtime.restoreCalls != 0 {
 		t.Fatalf("restore boot should not be attempted, got %d calls", runtime.restoreCalls)

internal/daemon/review_regressions_test.go

@@ -472,20 +472,10 @@ func TestRestoreSnapshotTransitionsToStartingWithoutRelayAllocation(t *testing.T
 	if err := os.WriteFile(snapDisk, []byte("disk"), 0o644); err != nil {
 		t.Fatalf("write snapshot disk: %v", err)
 	}
-	memPath := filepath.Join(snapDir, "memory.bin")
-	if err := os.WriteFile(memPath, []byte("mem"), 0o644); err != nil {
-		t.Fatalf("write memory snapshot: %v", err)
-	}
-	statePath := filepath.Join(snapDir, "vmstate.bin")
-	if err := os.WriteFile(statePath, []byte("state"), 0o644); err != nil {
-		t.Fatalf("write vmstate snapshot: %v", err)
-	}
 	if err := baseStore.CreateSnapshot(context.Background(), model.SnapshotRecord{
 		ID:                "snap-exhausted",
 		MachineID:         "source",
 		Artifact:          artifactRef,
-		MemFilePath:       memPath,
-		StateFilePath:     statePath,
 		DiskPaths:         []string{snapDisk},
 		SourceRuntimeHost: "172.16.0.2",
 		SourceTapDevice:   "fctap0",
@@ -495,11 +485,9 @@ func TestRestoreSnapshotTransitionsToStartingWithoutRelayAllocation(t *testing.T
 	}
 
 	server := newRestoreArtifactServer(t, map[string][]byte{
-		"/kernel":  []byte("kernel"),
+		"/kernel": []byte("kernel"),
-		"/rootfs":  []byte("rootfs"),
+		"/rootfs": []byte("rootfs"),
-		"/memory":  []byte("mem"),
+		"/system": []byte("disk"),
-		"/vmstate": []byte("state"),
-		"/system":  []byte("disk"),
 	})
 	defer server.Close()
 
@@ -514,8 +502,6 @@ func TestRestoreSnapshotTransitionsToStartingWithoutRelayAllocation(t *testing.T
 			MachineID:  "source",
 			ImageID:    "image-1",
 			Artifacts: []contracthost.SnapshotArtifact{
-				{ID: "memory", Kind: contracthost.SnapshotArtifactKindMemory, Name: "memory.bin", DownloadURL: server.URL + "/memory"},
-				{ID: "vmstate", Kind: contracthost.SnapshotArtifactKindVMState, Name: "vmstate.bin", DownloadURL: server.URL + "/vmstate"},
 				{ID: "disk-system", Kind: contracthost.SnapshotArtifactKindDisk, Name: "system.img", DownloadURL: server.URL + "/system"},
 			},
 		},
@@ -694,11 +680,9 @@ func TestRestoreSnapshotCleansStagingArtifactsAfterSuccess(t *testing.T) {
 	hostDaemon.reconfigureGuestIdentity = func(context.Context, string, contracthost.MachineID, *contracthost.GuestConfig) error { return nil }
 
 	server := newRestoreArtifactServer(t, map[string][]byte{
-		"/kernel":  []byte("kernel"),
+		"/kernel": []byte("kernel"),
-		"/rootfs":  []byte("rootfs"),
+		"/rootfs": []byte("rootfs"),
-		"/memory":  []byte("mem"),
+		"/system": []byte("disk"),
-		"/vmstate": []byte("state"),
-		"/system":  []byte("disk"),
 	})
 	defer server.Close()
 
@@ -715,8 +699,6 @@ func TestRestoreSnapshotCleansStagingArtifactsAfterSuccess(t *testing.T) {
 			SourceRuntimeHost: "172.16.0.2",
 			SourceTapDevice:   "fctap0",
 			Artifacts: []contracthost.SnapshotArtifact{
-				{ID: "memory", Kind: contracthost.SnapshotArtifactKindMemory, Name: "memory.bin", DownloadURL: server.URL + "/memory", SHA256Hex: mustSHA256Hex(t, []byte("mem"))},
-				{ID: "vmstate", Kind: contracthost.SnapshotArtifactKindVMState, Name: "vmstate.bin", DownloadURL: server.URL + "/vmstate", SHA256Hex: mustSHA256Hex(t, []byte("state"))},
 				{ID: "disk-system", Kind: contracthost.SnapshotArtifactKindDisk, Name: "system.img", DownloadURL: server.URL + "/system", SHA256Hex: mustSHA256Hex(t, []byte("disk"))},
 			},
 		},
@@ -749,7 +731,7 @@ func TestRestoreSnapshotCleansStagingArtifactsAfterDownloadFailure(t *testing.T)
 	server := newRestoreArtifactServer(t, map[string][]byte{
 		"/kernel": []byte("kernel"),
 		"/rootfs": []byte("rootfs"),
-		"/memory": []byte("mem"),
+		"/system": []byte("disk"),
 	})
 	defer server.Close()
 
@@ -766,8 +748,7 @@ func TestRestoreSnapshotCleansStagingArtifactsAfterDownloadFailure(t *testing.T)
 			SourceRuntimeHost: "172.16.0.2",
 			SourceTapDevice:   "fctap0",
 			Artifacts: []contracthost.SnapshotArtifact{
-				{ID: "memory", Kind: contracthost.SnapshotArtifactKindMemory, Name: "memory.bin", DownloadURL: server.URL + "/memory", SHA256Hex: mustSHA256Hex(t, []byte("mem"))},
+				{ID: "disk-system", Kind: contracthost.SnapshotArtifactKindDisk, Name: "system.img", DownloadURL: server.URL + "/missing"},
-				{ID: "vmstate", Kind: contracthost.SnapshotArtifactKindVMState, Name: "vmstate.bin", DownloadURL: server.URL + "/missing"},
 			},
 		},
 	})

internal/daemon/snapshot.go

@@ -3,7 +3,6 @@ package daemon
 import (
 	"context"
 	"fmt"
-	"io"
 	"os"
 	"path/filepath"
 	"sort"
@@ -13,7 +12,6 @@ import (
 
 	"golang.org/x/sync/errgroup"
 
-	"github.com/getcompanion-ai/computer-host/internal/firecracker"
 	"github.com/getcompanion-ai/computer-host/internal/httpapi"
 	"github.com/getcompanion-ai/computer-host/internal/model"
 	"github.com/getcompanion-ai/computer-host/internal/store"
@@ -85,20 +83,6 @@ func (d *Daemon) CreateSnapshot(ctx context.Context, machineID contracthost.Mach
 		return nil, fmt.Errorf("pause machine %q: %w", machineID, err)
 	}
 
-	// Write snapshot inside the chroot (Firecracker can only write there)
-	// Use jailed paths relative to the chroot root
-	chrootMemPath := "memory.bin"
-	chrootStatePath := "vmstate.bin"
-
-	if err := d.runtime.CreateSnapshot(ctx, runtimeState, firecracker.SnapshotPaths{
-		MemFilePath:   chrootMemPath,
-		StateFilePath: chrootStatePath,
-	}); err != nil {
-		_ = d.runtime.Resume(ctx, runtimeState)
-		_ = os.RemoveAll(snapshotDir)
-		return nil, fmt.Errorf("create snapshot for %q: %w", machineID, err)
-	}
-
 	// COW-copy disk files while paused for consistency
 	var diskPaths []string
 	systemVolume, err := d.store.GetVolume(ctx, record.SystemVolumeID)
@@ -137,24 +121,7 @@ func (d *Daemon) CreateSnapshot(ctx context.Context, machineID contracthost.Mach
 		return nil, fmt.Errorf("resume machine %q: %w", machineID, err)
 	}
 
-	// Copy snapshot files from chroot to snapshot directory, then remove originals.
+	artifacts, err := buildSnapshotArtifacts(diskPaths)
-	// os.Rename fails across filesystem boundaries (/proc/<pid>/root/ is on procfs).
-	chrootRoot := filepath.Dir(filepath.Dir(runtimeState.SocketPath)) // strip /run/firecracker.socket
-	srcMemPath := filepath.Join(chrootRoot, chrootMemPath)
-	srcStatePath := filepath.Join(chrootRoot, chrootStatePath)
-	dstMemPath := filepath.Join(snapshotDir, "memory.bin")
-	dstStatePath := filepath.Join(snapshotDir, "vmstate.bin")
-
-	if err := moveFile(srcMemPath, dstMemPath); err != nil {
-		_ = os.RemoveAll(snapshotDir)
-		return nil, fmt.Errorf("move memory file: %w", err)
-	}
-	if err := moveFile(srcStatePath, dstStatePath); err != nil {
-		_ = os.RemoveAll(snapshotDir)
-		return nil, fmt.Errorf("move vmstate file: %w", err)
-	}
-
-	artifacts, err := buildSnapshotArtifacts(dstMemPath, dstStatePath, diskPaths)
 	if err != nil {
 		_ = os.RemoveAll(snapshotDir)
 		return nil, fmt.Errorf("build snapshot artifacts: %w", err)
@@ -162,16 +129,12 @@ func (d *Daemon) CreateSnapshot(ctx context.Context, machineID contracthost.Mach
 
 	now := time.Now().UTC()
 	snapshotRecord := model.SnapshotRecord{
-		ID:                snapshotID,
+		ID:        snapshotID,
-		MachineID:         machineID,
+		MachineID: machineID,
-		Artifact:          record.Artifact,
+		Artifact:  record.Artifact,
-		MemFilePath:       dstMemPath,
+		DiskPaths: diskPaths,
-		StateFilePath:     dstStatePath,
+		Artifacts: artifacts,
-		DiskPaths:         diskPaths,
+		CreatedAt: now,
-		Artifacts:         artifacts,
-		SourceRuntimeHost: record.RuntimeHost,
-		SourceTapDevice:   record.TapDevice,
-		CreatedAt:         now,
 	}
 	if err := d.store.CreateSnapshot(ctx, snapshotRecord); err != nil {
 		_ = os.RemoveAll(snapshotDir)
@@ -276,11 +239,7 @@ func (d *Daemon) RestoreSnapshot(ctx context.Context, snapshotID contracthost.Sn
 		}
 	}()
 
-	usedNetworks, err := d.listRunningNetworks(ctx, req.MachineID)
+	restoredArtifacts, cleanupRestoreArtifacts, err := d.prepareRestoreArtifacts(ctx, snapshotID, req)
-	if err != nil {
-		return nil, err
-	}
-	restoredArtifacts, restoreNetwork, cleanupRestoreArtifacts, err := d.prepareRestoreArtifacts(ctx, snapshotID, req, usedNetworks)
 	if err != nil {
 		clearOperation = true
 		return nil, err
@@ -302,16 +261,6 @@ func (d *Daemon) RestoreSnapshot(ctx context.Context, snapshotID contracthost.Sn
 		clearOperation = true
 		return nil, fmt.Errorf("snapshot %q is missing system disk artifact", snapshotID)
 	}
-	memoryArtifact, ok := restoredArtifacts["memory.bin"]
-	if !ok {
-		clearOperation = true
-		return nil, fmt.Errorf("snapshot %q is missing memory artifact", snapshotID)
-	}
-	vmstateArtifact, ok := restoredArtifacts["vmstate.bin"]
-	if !ok {
-		clearOperation = true
-		return nil, fmt.Errorf("snapshot %q is missing vmstate artifact", snapshotID)
-	}
 	if err := cloneDiskFile(systemDiskPath.LocalPath, newSystemDiskPath, d.config.DiskCloneMode); err != nil {
 		clearOperation = true
 		return nil, fmt.Errorf("copy system disk for restore: %w", err)
@@ -341,24 +290,31 @@ func (d *Daemon) RestoreSnapshot(ctx context.Context, snapshotID contracthost.Sn
 		restoredDrivePaths[driveID] = volumePath
 	}
 
-	// Do not force vsock_override on restore: Firecracker rejects it for old
+	userVolumes := make([]model.VolumeRecord, 0, len(restoredUserVolumes))
-	// snapshots without a vsock device, and the jailed /run path already
+	for _, volume := range restoredUserVolumes {
-	// relocates safely for snapshots created with the new vsock-backed guest.
+		userVolumes = append(userVolumes, model.VolumeRecord{
-	loadSpec := firecracker.SnapshotLoadSpec{
+			ID:   volume.ID,
-		ID:              firecracker.MachineID(req.MachineID),
+			Kind: contracthost.VolumeKindUser,
-		SnapshotPath:    vmstateArtifact.LocalPath,
+			Path: volume.Path,
-		MemFilePath:     memoryArtifact.LocalPath,
+		})
-		RootFSPath:      newSystemDiskPath,
-		KernelImagePath: artifact.KernelImagePath,
-		DiskPaths:       restoredDrivePaths,
-		Network:         &restoreNetwork,
 	}
-
+	spec, err := d.buildMachineSpec(req.MachineID, artifact, userVolumes, newSystemDiskPath, guestConfig)
-	machineState, err := d.runtime.RestoreBoot(ctx, loadSpec, usedNetworks)
 	if err != nil {
 		_ = os.RemoveAll(filepath.Dir(newSystemDiskPath))
 		clearOperation = true
-		return nil, fmt.Errorf("restore boot: %w", err)
+		return nil, fmt.Errorf("build machine spec for restore: %w", err)
+	}
+	usedNetworks, err := d.listRunningNetworks(ctx, req.MachineID)
+	if err != nil {
+		_ = os.RemoveAll(filepath.Dir(newSystemDiskPath))
+		clearOperation = true
+		return nil, err
+	}
+	machineState, err := d.runtime.Boot(ctx, spec, usedNetworks)
+	if err != nil {
+		_ = os.RemoveAll(filepath.Dir(newSystemDiskPath))
+		clearOperation = true
+		return nil, fmt.Errorf("boot restored machine: %w", err)
 	}
 
 	systemVolumeID := d.systemVolumeID(req.MachineID)
@@ -556,86 +512,39 @@ func restoredUserDiskIndex(name string) (int, bool) {
 	return index, true
 }
 
-func (d *Daemon) prepareRestoreArtifacts(ctx context.Context, snapshotID contracthost.SnapshotID, req contracthost.RestoreSnapshotRequest, usedNetworks []firecracker.NetworkAllocation) (map[string]restoredSnapshotArtifact, firecracker.NetworkAllocation, func(), error) {
+func (d *Daemon) prepareRestoreArtifacts(ctx context.Context, snapshotID contracthost.SnapshotID, req contracthost.RestoreSnapshotRequest) (map[string]restoredSnapshotArtifact, func(), error) {
 	if req.LocalSnapshot != nil {
 		if req.LocalSnapshot.SnapshotID != "" && req.LocalSnapshot.SnapshotID != snapshotID {
-			return nil, firecracker.NetworkAllocation{}, func() {}, fmt.Errorf("local snapshot id mismatch: path=%q payload=%q", snapshotID, req.LocalSnapshot.SnapshotID)
+			return nil, func() {}, fmt.Errorf("local snapshot id mismatch: path=%q payload=%q", snapshotID, req.LocalSnapshot.SnapshotID)
 		}
 		snapshot, err := d.store.GetSnapshot(ctx, snapshotID)
 		if err != nil {
 			if err == store.ErrNotFound {
-				return nil, firecracker.NetworkAllocation{}, func() {}, localSnapshotRestoreUnavailable(snapshotID, "snapshot is not present on this host")
+				return nil, func() {}, localSnapshotRestoreUnavailable(snapshotID, "snapshot is not present on this host")
 			}
-			return nil, firecracker.NetworkAllocation{}, func() {}, err
+			return nil, func() {}, err
-		}
-		restoreNetwork, err := restoreNetworkFromSnapshot(snapshot)
-		if err != nil {
-			return nil, firecracker.NetworkAllocation{}, func() {}, localSnapshotRestoreUnavailable(snapshotID, err.Error())
-		}
-		if networkAllocationInUse(restoreNetwork, usedNetworks) {
-			return nil, firecracker.NetworkAllocation{}, func() {}, localSnapshotRestoreUnavailable(snapshotID, fmt.Sprintf("restore network is still in use on this host (runtime_host=%s tap_device=%s)", restoreNetwork.GuestIP(), restoreNetwork.TapName))
 		}
 		artifacts, err := localSnapshotArtifacts(snapshot)
 		if err != nil {
-			return nil, firecracker.NetworkAllocation{}, func() {}, localSnapshotRestoreUnavailable(snapshotID, err.Error())
+			return nil, func() {}, localSnapshotRestoreUnavailable(snapshotID, err.Error())
 		}
-		return artifacts, restoreNetwork, func() {}, nil
+		return artifacts, func() {}, nil
 	}
 
 	if req.Snapshot == nil {
-		return nil, firecracker.NetworkAllocation{}, func() {}, fmt.Errorf("durable snapshot spec is required")
+		return nil, func() {}, fmt.Errorf("durable snapshot spec is required")
-	}
-	restoreNetwork, err := restoreNetworkFromDurableSpec(*req.Snapshot)
-	if err != nil {
-		snapshot, lookupErr := d.store.GetSnapshot(ctx, snapshotID)
-		if lookupErr == nil {
-			restoreNetwork, err = restoreNetworkFromSnapshot(snapshot)
-		} else if lookupErr != store.ErrNotFound {
-			return nil, firecracker.NetworkAllocation{}, func() {}, lookupErr
-		}
-		if err != nil {
-			return nil, firecracker.NetworkAllocation{}, func() {}, err
-		}
-	}
-	if networkAllocationInUse(restoreNetwork, usedNetworks) {
-		return nil, firecracker.NetworkAllocation{}, func() {}, fmt.Errorf("restore network for snapshot %q is still in use on this host (runtime_host=%s tap_device=%s)", snapshotID, restoreNetwork.GuestIP(), restoreNetwork.TapName)
 	}
 	stagingDir := filepath.Join(d.config.SnapshotsDir, string(snapshotID), "restores", string(req.MachineID))
 	artifacts, err := downloadDurableSnapshotArtifacts(ctx, stagingDir, req.Snapshot.Artifacts)
 	if err != nil {
 		_ = os.RemoveAll(stagingDir)
-		return nil, firecracker.NetworkAllocation{}, func() {}, fmt.Errorf("download durable snapshot artifacts: %w", err)
+		return nil, func() {}, fmt.Errorf("download durable snapshot artifacts: %w", err)
 	}
-	return artifacts, restoreNetwork, func() {
+	return artifacts, func() {
 		_ = os.RemoveAll(stagingDir)
 	}, nil
 }
 
-func restoreNetworkFromDurableSpec(spec contracthost.DurableSnapshotSpec) (firecracker.NetworkAllocation, error) {
-	if strings.TrimSpace(spec.SourceRuntimeHost) == "" || strings.TrimSpace(spec.SourceTapDevice) == "" {
-		return firecracker.NetworkAllocation{}, fmt.Errorf("durable snapshot spec is missing restore network metadata")
-	}
-	network, err := firecracker.AllocationFromGuestIP(spec.SourceRuntimeHost, spec.SourceTapDevice)
-	if err != nil {
-		return firecracker.NetworkAllocation{}, fmt.Errorf("reconstruct durable snapshot %q network: %w", spec.SnapshotID, err)
-	}
-	return network, nil
-}
-
-func restoreNetworkFromSnapshot(snap *model.SnapshotRecord) (firecracker.NetworkAllocation, error) {
-	if snap == nil {
-		return firecracker.NetworkAllocation{}, fmt.Errorf("snapshot is required")
-	}
-	if strings.TrimSpace(snap.SourceRuntimeHost) == "" || strings.TrimSpace(snap.SourceTapDevice) == "" {
-		return firecracker.NetworkAllocation{}, fmt.Errorf("snapshot %q is missing restore network metadata", snap.ID)
-	}
-	network, err := firecracker.AllocationFromGuestIP(snap.SourceRuntimeHost, snap.SourceTapDevice)
-	if err != nil {
-		return firecracker.NetworkAllocation{}, fmt.Errorf("reconstruct snapshot %q network: %w", snap.ID, err)
-	}
-	return network, nil
-}
-
 func localSnapshotArtifacts(snapshot *model.SnapshotRecord) (map[string]restoredSnapshotArtifact, error) {
 	if snapshot == nil {
 		return nil, fmt.Errorf("snapshot is required")
@@ -662,19 +571,6 @@ func localSnapshotArtifacts(snapshot *model.SnapshotRecord) (map[string]restored
 	return restored, nil
 }
 
-func networkAllocationInUse(target firecracker.NetworkAllocation, used []firecracker.NetworkAllocation) bool {
-	targetTap := strings.TrimSpace(target.TapName)
-	for _, network := range used {
-		if network.GuestIP() == target.GuestIP() {
-			return true
-		}
-		if targetTap != "" && strings.TrimSpace(network.TapName) == targetTap {
-			return true
-		}
-	}
-	return false
-}
-
 func localSnapshotRestoreUnavailable(snapshotID contracthost.SnapshotID, message string) error {
 	message = strings.TrimSpace(message)
 	if message == "" {
@@ -682,31 +578,3 @@ func localSnapshotRestoreUnavailable(snapshotID contracthost.SnapshotID, message
 	}
 	return fmt.Errorf("%s: snapshot %q %s", localSnapshotRestoreUnavailablePrefix, snapshotID, message)
 }
-
-// moveFile copies src to dst then removes src. Works across filesystem boundaries
-// unlike os.Rename, which is needed when moving files out of /proc/<pid>/root/.
-func moveFile(src, dst string) error {
-	in, err := os.Open(src)
-	if err != nil {
-		return err
-	}
-	defer func() {
-		_ = in.Close()
-	}()
-
-	out, err := os.Create(dst)
-	if err != nil {
-		return err
-	}
-
-	if _, err := io.Copy(out, in); err != nil {
-		_ = out.Close()
-		_ = os.Remove(dst)
-		return err
-	}
-	if err := out.Close(); err != nil {
-		_ = os.Remove(dst)
-		return err
-	}
-	return os.Remove(src)
-}

internal/daemon/snapshot_transfer.go

@@ -21,21 +21,8 @@ type restoredSnapshotArtifact struct {
 	LocalPath string
 }
 
-func buildSnapshotArtifacts(memoryPath, vmstatePath string, diskPaths []string) ([]model.SnapshotArtifactRecord, error) {
+func buildSnapshotArtifacts(diskPaths []string) ([]model.SnapshotArtifactRecord, error) {
-	artifacts := make([]model.SnapshotArtifactRecord, 0, len(diskPaths)+2)
+	artifacts := make([]model.SnapshotArtifactRecord, 0, len(diskPaths))
-
-	memoryArtifact, err := snapshotArtifactRecord("memory", contracthost.SnapshotArtifactKindMemory, filepath.Base(memoryPath), memoryPath)
-	if err != nil {
-		return nil, err
-	}
-	artifacts = append(artifacts, memoryArtifact)
-
-	vmstateArtifact, err := snapshotArtifactRecord("vmstate", contracthost.SnapshotArtifactKindVMState, filepath.Base(vmstatePath), vmstatePath)
-	if err != nil {
-		return nil, err
-	}
-	artifacts = append(artifacts, vmstateArtifact)
-
 	for _, diskPath := range diskPaths {
 		base := filepath.Base(diskPath)
 		diskArtifact, err := snapshotArtifactRecord("disk-"+strings.TrimSuffix(base, filepath.Ext(base)), contracthost.SnapshotArtifactKindDisk, base, diskPath)