From 9bda3a52fae8c51ebdac88084fd65de4f94905c7 Mon Sep 17 00:00:00 2001
From: Lemon-miaow <admin@lemonmiaow.xyz>
Date: Thu, 24 Sep 2026 19:58:59 +0800
Subject: [PATCH] =?UTF-8?q?fix(backup):=20=E6=89=8B=E5=8A=A8=E5=A4=87?=
 =?UTF-8?q?=E4=BB=BD=E6=8C=89=E6=9C=8D=E5=86=B7=E5=8D=B4=E3=80=81=E6=AF=8F?=
 =?UTF-8?q?=E6=9C=8D=E4=BF=9D=E7=95=99=E4=B8=8A=E9=99=90=E4=B8=8E=E7=8B=AC?=
 =?UTF-8?q?=E7=AB=8B=E4=BF=9D=E7=95=99=E6=9C=9F=EF=BC=8C=E5=AE=B9=E9=87=8F?=
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---
 cmd/felis/api.go                            | 14 +++
 cmd/felis/backup.go                         | 41 ++++++++-
 cmd/felis/reaper.go                         | 25 +++++-
 cmd/felis/reaper_test.go                    | 34 ++++++++
 deploy/bootstrap.sh                         | 17 ++--
 deploy/bootstrap_test.sh                    |  4 +
 docs/troubleshooting.md                     | 32 ++++++-
 internal/api/api.go                         |  8 ++
 internal/api/api_test.go                    | 26 ++++++
 internal/api/handlers_backup_now_test.go    | 74 ++++++++++++++++
 internal/api/handlers_backups.go            | 41 +++++++++
 internal/api/jobstatus_test.go              | 58 +++++++++++++
 internal/api/k8sjobstatus.go                | 59 +++++++++++++
 internal/api/pgrepo.go                      | 22 +++++
 internal/api/repo.go                        |  8 ++
 internal/backup/room.go                     | 93 ++++++++++++++++++++
 internal/backup/room_test.go                | 26 ++++++
 internal/backupjob/jobspec.go               |  4 +
 internal/config/config.go                   | 19 +++--
 internal/pgint/reaper_test.go               | 94 +++++++++++++++++++++
 internal/reaper/pgstore.go                  | 24 ++++--
 internal/reaper/reaper.go                   | 33 ++++++--
 internal/reaper/reaper_test.go              | 63 ++++++++++++--
 internal/restore/jobspec.go                 |  4 +
 panel/src/i18n/resources/en-US/backups.json |  2 +-
 panel/src/i18n/resources/en-US/errors.json  |  2 +
 panel/src/i18n/resources/zh-CN/backups.json |  2 +-
 panel/src/i18n/resources/zh-CN/errors.json  |  2 +
 panel/src/lib/api.test.ts                   |  6 ++
 panel/src/lib/api.ts                        |  6 ++
 30 files changed, 801 insertions(+), 42 deletions(-)
 create mode 100644 internal/backup/room.go
 create mode 100644 internal/backup/room_test.go

diff --git a/cmd/felis/api.go b/cmd/felis/api.go
index 706e703..c495721 100644
--- a/cmd/felis/api.go
+++ b/cmd/felis/api.go
@@ -24,6 +24,7 @@ import (
 	"felis.lolicon.best/internal/panel"
 	"felis.lolicon.best/internal/passkey"
 	"felis.lolicon.best/internal/platform"
+	"felis.lolicon.best/internal/reaper"
 	"felis.lolicon.best/internal/restore"
 	"felis.lolicon.best/internal/store"
 	"felis.lolicon.best/internal/submit"
@@ -262,6 +263,15 @@ func cmdAPI(args []string, stdout, stderr io.Writer) int {
 	// agree on what local auth knows.
 	repo := api.NewPGRepo(drv.DB())
 
+	// The owner's on-demand backup levers come from [archive], the same keys the
+	// backup Job and the reaper read. A malformed key leaves the defaults in
+	// place here; the reaper Job fails on it and names it.
+	rcfg, err := reaperConfig(cfg)
+	if err != nil {
+		fmt.Fprintf(stderr, "felis api: %v; using the default backup limits\n", err)
+		rcfg = reaper.DefaultConfig()
+	}
+
 	a := &api.API{
 		Repo:    repo,
 		Cluster: api.NewK8sCluster(cl, cfg.K8s.Namespace),
@@ -296,6 +306,10 @@ func cmdAPI(args []string, stdout, stderr io.Writer) int {
 		AdminHostname: cfg.Auth.AdminHostname,
 		PanelHostname: cfg.Auth.PanelHostname,
 		WakeCooldown:  30 * time.Second,
+		// An owner may start one backup per server per manual_cooldown, and none
+		// while the store is at max_local_bytes (data-durability-9).
+		BackupCooldown: rcfg.ManualCooldown,
+		BackupStoreCap: rcfg.MaxLocalBytes,
 		// The user-modpack lane's per-user throttles: a create spaces out
 		// review-queue rows, an upload spaces out (up to 1 GiB) context streams.
 		// Separate keys, so the normal create→upload sequence stays immediate.
diff --git a/cmd/felis/backup.go b/cmd/felis/backup.go
index 5d790bf..01924c5 100644
--- a/cmd/felis/backup.go
+++ b/cmd/felis/backup.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"context"
 	"crypto/rand"
 	"encoding/hex"
 	"flag"
@@ -52,8 +53,8 @@ func cmdBackup(args []string, stdout, stderr io.Writer) int {
 		fmt.Fprintf(stderr, "felis backup: archive store %q is not implemented in this build (only tarLocal)\n", cfg.Archive.Store)
 		return 1
 	}
-	// Reuse the reaper's retention derivation so an on-demand backup expires on the
-	// same clock as an inactivity backup — one retention policy, not two.
+	// The [archive] parse the reaper uses; an on-demand backup takes its
+	// manual_retention and manual_keep.
 	rcfg, err := reaperConfig(cfg)
 	if err != nil {
 		fmt.Fprintf(stderr, "felis backup: %v\n", err)
@@ -72,6 +73,13 @@ func cmdBackup(args []string, stdout, stderr io.Writer) int {
 
 	ctx := ctrl.SetupSignalHandler()
 
+	// The archive store shares the node's disk with every world and the
+	// database: an owner's backup must not be what tips it into eviction.
+	if err := backup.CheckRoom(cfg.Archive.LocalPath, *worldsRoot, backup.MinFreeAfter); err != nil {
+		fmt.Fprintf(stderr, "felis backup: %v\n", err)
+		return 1
+	}
+
 	ref, size, err := archiver.Archive(ctx, *server, naming.WorldPVCName(*server))
 	if err != nil {
 		fmt.Fprintf(stderr, "felis backup: archive: %v\n", err)
@@ -92,9 +100,10 @@ func cmdBackup(args []string, stdout, stderr io.Writer) int {
 		BackupRef:   string(ref),
 		SizeBytes:   size,
 		Reason:      "manual",
-		ExpiresAt:   time.Now().Add(rcfg.Retention),
+		ExpiresAt:   time.Now().Add(rcfg.ManualRetention),
 	}
-	if err := reaper.NewPGStore(drv.DB()).InsertBackup(ctx, rec); err != nil {
+	st := reaper.NewPGStore(drv.DB())
+	if err := st.InsertBackup(ctx, rec); err != nil {
 		// The archive is written but unrecorded — an orphan the retention pass would
 		// never expire. Delete it so a failed backup leaves no leaked bytes, mirroring
 		// the reaper's archive-then-record atomicity.
@@ -107,9 +116,33 @@ func cmdBackup(args []string, stdout, stderr io.Writer) int {
 	}
 
 	fmt.Fprintf(stdout, "felis backup: server=%s archived %d bytes to %s (backup %s)\n", *server, size, ref, rec.ID)
+	pruneManualBackups(ctx, st, archiver, *server, rcfg.ManualKeep, stdout, stderr)
 	return 0
 }
 
+// pruneManualBackups keeps server's newest keep on-demand backups and removes
+// the rest, oldest first, so repeated backups of one world cannot fill the
+// shared archive store. The new backup is already recorded; a removal that
+// fails is reported and retried after the next backup.
+func pruneManualBackups(ctx context.Context, st *reaper.PGStore, archiver backup.WorldArchiver, server string, keep int, stdout, stderr io.Writer) {
+	excess, err := st.ExcessManualBackups(ctx, server, keep)
+	if err != nil {
+		fmt.Fprintf(stderr, "felis backup: list older backups of %s: %v\n", server, err)
+		return
+	}
+	for _, b := range excess {
+		if err := archiver.Delete(ctx, backup.ArchiveRef(b.BackupRef)); err != nil {
+			fmt.Fprintf(stderr, "felis backup: remove older backup %s: %v\n", b.ID, err)
+			continue
+		}
+		if err := st.MarkBackupDeleted(ctx, b.ID, time.Now()); err != nil {
+			fmt.Fprintf(stderr, "felis backup: record the removal of %s: %v\n", b.ID, err)
+			continue
+		}
+		fmt.Fprintf(stdout, "felis backup: removed older backup %s of %s (keeping the newest %d)\n", b.ID, server, keep)
+	}
+}
+
 // newBackupID mints a world_backups primary key, matching the reaper's "bk-"+hex
 // scheme so a manual and an inactivity backup are indistinguishable downstream.
 func newBackupID() string {
diff --git a/cmd/felis/reaper.go b/cmd/felis/reaper.go
index 51e2ad3..031ffef 100644
--- a/cmd/felis/reaper.go
+++ b/cmd/felis/reaper.go
@@ -183,8 +183,9 @@ func (w *mailWarner) Warn(ctx context.Context, ownerID, server, remaining string
 }
 
 // reaperConfig derives the reaper's retention windows from felis.toml. The 15d
-// idle deadline is fixed by §18; only the warning offsets, retention, and the
-// store soft-cap are configurable (§24).
+// idle deadline is fixed by §18; only the warning offsets, retention, the
+// store soft-cap and the on-demand backup bounds are configurable (§24). The
+// backup Job and felis-api read the manual_* bounds through it too.
 func reaperConfig(cfg *config.Config) (reaper.Config, error) {
 	rc := reaper.DefaultConfig()
 	if v := cfg.Archive.Retention; v != "" {
@@ -212,6 +213,26 @@ func reaperConfig(cfg *config.Config) (reaper.Config, error) {
 		}
 		rc.MaxLocalBytes = b
 	}
+	if v := cfg.Archive.ManualRetention; v != "" {
+		d, err := parseSpanDuration(v)
+		if err != nil || d <= 0 {
+			return rc, fmt.Errorf("[archive] manual_retention %q: want a positive span such as 30d", v)
+		}
+		rc.ManualRetention = d
+	}
+	switch n := cfg.Archive.ManualKeep; {
+	case n < 0:
+		return rc, fmt.Errorf("[archive] manual_keep %d: want 1 or more", n)
+	case n > 0:
+		rc.ManualKeep = n
+	}
+	if v := cfg.Archive.ManualCooldown; v != "" {
+		d, err := parseSpanDuration(v)
+		if err != nil || d < 0 {
+			return rc, fmt.Errorf("[archive] manual_cooldown %q: want a span such as 10m (0s for none)", v)
+		}
+		rc.ManualCooldown = d
+	}
 	rc.RequireOffsite = cfg.Offsite.Enabled()
 	return rc, nil
 }
diff --git a/cmd/felis/reaper_test.go b/cmd/felis/reaper_test.go
index 376c53e..85e4d86 100644
--- a/cmd/felis/reaper_test.go
+++ b/cmd/felis/reaper_test.go
@@ -8,11 +8,13 @@ import (
 	"path/filepath"
 	"strings"
 	"testing"
+	"time"
 
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"sigs.k8s.io/controller-runtime/pkg/client/fake"
 
+	"felis.lolicon.best/internal/config"
 	"felis.lolicon.best/internal/reaper"
 )
 
@@ -46,6 +48,38 @@ func TestReportReaperRunFailsTheJob(t *testing.T) {
 // fail-closed miss. The stock local-path arm is derived from the live PVC's
 // volumeName — a name-based guess (glob) could tar a stale deleted PV's bytes and
 // then delete the current world, which is why it is read from the API instead.
+// TestReaperConfigManualKeys: the on-demand backup keys default to 30 days,
+// five per server and a ten-minute cooldown, accept overrides, and refuse
+// values that would keep nothing or throttle backwards.
+func TestReaperConfigManualKeys(t *testing.T) {
+	rc, err := reaperConfig(&config.Config{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if rc.ManualRetention != 30*reaper.Day || rc.ManualKeep != 5 || rc.ManualCooldown != 10*time.Minute {
+		t.Fatalf("defaults = %v / %d / %v", rc.ManualRetention, rc.ManualKeep, rc.ManualCooldown)
+	}
+	rc, err = reaperConfig(&config.Config{Archive: config.ArchiveConfig{
+		ManualRetention: "7d", ManualKeep: 2, ManualCooldown: "0s"}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if rc.ManualRetention != 7*reaper.Day || rc.ManualKeep != 2 || rc.ManualCooldown != 0 {
+		t.Fatalf("overrides = %v / %d / %v", rc.ManualRetention, rc.ManualKeep, rc.ManualCooldown)
+	}
+	for _, bad := range []config.ArchiveConfig{
+		{ManualRetention: "0d"},
+		{ManualRetention: "soon"},
+		{ManualKeep: -1},
+		{ManualCooldown: "-5m"},
+		{ManualCooldown: "often"},
+	} {
+		if _, err := reaperConfig(&config.Config{Archive: bad}); err == nil {
+			t.Errorf("%+v was accepted", bad)
+		}
+	}
+}
+
 func TestResolveWorldDir(t *testing.T) {
 	ctx := context.Background()
 	root := t.TempDir()
diff --git a/deploy/bootstrap.sh b/deploy/bootstrap.sh
index e9e7d21..2932953 100644
--- a/deploy/bootstrap.sh
+++ b/deploy/bootstrap.sh
@@ -2314,13 +2314,14 @@ persisted_auth_source_blocks() {
 }
 
 # persisted_archive_block echoes the operator-owned [archive] keys an earlier run
-# left behind — the retention window, the pre-reap warn offsets, the local cap —
-# so a re-run does not silently revert them to the built-ins the reaper carries
-# (felis reaper reads these from the config Secret at run time; defaults: 90d
-# retention, 3d/1d warnings, no cap). store and local_path are NOT carried: this
-# script owns them (FELIS_ARCHIVE_LOCAL_PATH must equal the mount). Same
-# first-readable-file rule as persisted_smtp_block; warn_before must be a
-# single-line TOML array (the shape every writer here emits).
+# left behind — the retention window, the pre-reap warn offsets, the local cap,
+# the on-demand backup retention/count/cooldown — so a re-run does not silently
+# revert them to the built-ins (felis reaper, felis backup and felis api read
+# these from the config Secret; defaults: 90d retention, 3d/1d warnings, no cap,
+# manual backups kept 30d, 5 per server, one per 10m). store and local_path are
+# NOT carried: this script owns them (FELIS_ARCHIVE_LOCAL_PATH must equal the
+# mount). Same first-readable-file rule as persisted_smtp_block; warn_before must
+# be a single-line TOML array (the shape every writer here emits).
 persisted_archive_block() {
   local f out
   for f in "${STATE_DIR}/felis.host.toml" "${STATE_DIR}/felis.pod.toml"; do
@@ -2328,7 +2329,7 @@ persisted_archive_block() {
     out="$(awk '
       /^[[:space:]]*\[/ { sect = $0; next }
       sect ~ /^[[:space:]]*\[archive\][[:space:]]*$/ &&
-        /^[[:space:]]*(retention|warn_before|max_local_bytes)[[:space:]]*=/ { print }
+        /^[[:space:]]*(retention|warn_before|max_local_bytes|manual_retention|manual_keep|manual_cooldown)[[:space:]]*=/ { print }
     ' "$f")"
     [ -n "$out" ] || continue
     printf '%s\n' "$out"
diff --git a/deploy/bootstrap_test.sh b/deploy/bootstrap_test.sh
index 09263bb..a4066ef 100644
--- a/deploy/bootstrap_test.sh
+++ b/deploy/bootstrap_test.sh
@@ -1046,6 +1046,8 @@ region = "us-east-1"
 store = "tarLocal"
 local_path = "/stale/path"
 retention = "30d"
+manual_keep = 3
+manual_cooldown = "1h"
 
 [offsite]
 endpoint = "https://objects.example"
@@ -1076,6 +1078,8 @@ expect "a re-run carries the [registry.s3] uploads subtable" "[registry.s3]" "$o
 expect "the carried subtable keeps its keys" 'endpoint = "https://s3.example"' "$out"
 expect "url stays installer-owned" 'url = "registry.felis.svc:5000"' "$out"
 expect "a re-run carries the archive retention window" 'retention = "30d"' "$out"
+expect "a re-run carries the on-demand backup count" 'manual_keep = 3' "$out"
+expect "a re-run carries the on-demand backup cooldown" 'manual_cooldown = "1h"' "$out"
 expect "the archive mount stays installer-owned" 'local_path = "/a"' "$out"
 expect "a re-run keeps the off-site bucket, set apart from the next section" '[offsite]
 endpoint = "https://objects.example"
diff --git a/docs/troubleshooting.md b/docs/troubleshooting.md
index 90fc77a..62d80dc 100644
--- a/docs/troubleshooting.md
+++ b/docs/troubleshooting.md
@@ -624,7 +624,8 @@ Registry manifest rendering is [GO-TESTED]; actual serving is
 The reaper is a **run-once daily CronJob batch**, not an operator controller. It
 reaps a world only when `now - last_active_at > 15d` (`inactive_15d`); the 15-day
 deadline is **hard-fixed in code** (only `warn_before` / `retention` /
-`max_local_bytes` are configurable from `felis.toml [archive]`).
+`max_local_bytes` and the on-demand backup keys `manual_retention` /
+`manual_keep` / `manual_cooldown` are configurable from `felis.toml [archive]`).
 
 ### What a "backup" contains
 
@@ -641,8 +642,13 @@ world growth) — do not size the archive PVC as if only world data were stored.
 The reap sequence (all [GO-TESTED] hermetically) preserves the world unless a
 **confirmed, DB-recorded backup exists**:
 
-1. `ensureCapacity` (only if `max_local_bytes > 0`) → store full ⇒ world
-   **preserved** (not deleted).
+1. `ensureCapacity` (only if `max_local_bytes > 0`) frees room by evicting
+   owners' on-demand backups first, oldest first, then reaper archives whose
+   off-site copy is confirmed. The only copy of a reaped world is never
+   evicted: it stays until `retention` expires it. Still full ⇒ world
+   **preserved** (not deleted), counted in `store_full=`. [GO-TESTED:
+   `TestCapacityEvictionOrderSparesSoleCopies`; PG-TESTED:
+   `TestManualBackupRationing`]
 2. `Archiver.Archive` fails ⇒ world **preserved**, PVC untouched.
 3. `InsertBackup` (DB) fails ⇒ the orphan archive is deleted, PVC **untouched**.
 4. With an `[offsite]` bucket configured (§16), the archive must also be in the
@@ -689,6 +695,26 @@ reports `the world reaper has not succeeded for …`. [GO-TESTED:
 `TestReportReaperRunFailsTheJob`, `TestExpiryFailureFailsTheRun`,
 `TestCapacityStillFullSkipsReap`.]
 
+### On-demand backups ("Back up now")
+
+An owner's "Back up now" writes a `manual` backup into the same store and onto
+the same disk as the worlds and the database, so it is rationed:
+
+| Key | Default | Effect |
+|---|---|---|
+| `manual_retention` | `30d` | when a manual backup expires (reaper archives use `retention`) |
+| `manual_keep` | `5` | manual backups kept per server; after each backup the Job removes older ones and prints `removed older backup …` |
+| `manual_cooldown` | `10m` | one owner-started backup per server per window; the next one gets `429 backup_cooldown` with `Retry-After` (`0s` disables) |
+
+While the present backups add up to `max_local_bytes` or more, owners get
+`507 backup_store_full`. Admins and the break-glass console are exempt from the
+cooldown and the cap. Whoever starts it, the backup Job refuses to write an
+archive that would leave less than 10% of the archive filesystem free: it fails
+with `not enough free disk for the archive`. A failed backup or restore shows
+the error its container exited on under Recent operations on the server's
+backup page. [GO-TESTED: `TestBackupNow`, `TestCheckRoom`,
+`TestReaperConfigManualKeys`, `TestLatestJobsExplainsFailures`]
+
 ### Exemptions (world never reaped)
 
 - `spec.reaperExempt=true` → skipped entirely (system servers). [GO-TESTED
diff --git a/internal/api/api.go b/internal/api/api.go
index 7efb7c7..f5ca662 100644
--- a/internal/api/api.go
+++ b/internal/api/api.go
@@ -128,6 +128,14 @@ type API struct {
 	// on the wake lever). Zero disables throttling.
 	WakeCooldown time.Duration
 
+	// BackupCooldown spaces out an owner's on-demand backups of one server, and
+	// BackupStoreCap refuses them once the present backups reach [archive]
+	// max_local_bytes (data-durability-9): each archive lands on the node disk
+	// the worlds and the database share. Admins and the break-glass console are
+	// exempt. Zero disables each lever.
+	BackupCooldown time.Duration
+	BackupStoreCap int64
+
 	// SubmitCreateCooldown / SubmitUploadCooldown throttle the user-modpack
 	// submission lane per user: create bounds how quickly review-queue rows can
 	// appear, upload bounds how often a user may stream a (up to 1 GiB) build
diff --git a/internal/api/api_test.go b/internal/api/api_test.go
index 17b709f..2071d37 100644
--- a/internal/api/api_test.go
+++ b/internal/api/api_test.go
@@ -48,6 +48,9 @@ type fakeRepo struct {
 	resourceUpdates map[string]ResourceSpec
 	audits          []AuditEntry
 	failAudit       error // Audit fails with it (a store outage)
+	// backupRequested mirrors the newest backup.create audit row per server,
+	// stamped by Audit with the wall clock (LastBackupRequest).
+	backupRequested map[string]time.Time
 	joins           []string
 	// create-server seeding (spec §15)
 	seeded  map[string]bool   // name -> servers row exists
@@ -750,9 +753,32 @@ func (f *fakeRepo) Audit(_ context.Context, e AuditEntry) error {
 		return f.failAudit
 	}
 	f.audits = append(f.audits, e)
+	if e.Action == "backup.create" {
+		if f.backupRequested == nil {
+			f.backupRequested = map[string]time.Time{}
+		}
+		f.backupRequested[e.ServerName] = time.Now()
+	}
 	return nil
 }
 
+func (f *fakeRepo) LastBackupRequest(_ context.Context, serverName string, since time.Time) (time.Time, error) {
+	if at, ok := f.backupRequested[serverName]; ok && !at.Before(since) {
+		return at, nil
+	}
+	return time.Time{}, nil
+}
+
+func (f *fakeRepo) BackupStoreBytes(context.Context) (int64, error) {
+	var n int64
+	for _, b := range f.backups {
+		if b.view.Status == "present" {
+			n += b.view.SizeBytes
+		}
+	}
+	return n, nil
+}
+
 // AllBackups / BackupsForUser / LatestBackup mirror the PG queries' contract so
 // the hermetic tests can't pass against a too-lenient fake: only status='present'
 // rows are visible, the user scope is the former_owner column, and LatestBackup
diff --git a/internal/api/handlers_backup_now_test.go b/internal/api/handlers_backup_now_test.go
index d641856..f70a00a 100644
--- a/internal/api/handlers_backup_now_test.go
+++ b/internal/api/handlers_backup_now_test.go
@@ -5,7 +5,9 @@ import (
 	"encoding/json"
 	"errors"
 	"net/http"
+	"strconv"
 	"testing"
+	"time"
 
 	"felis.lolicon.best/internal/apis/felis/v1alpha1"
 )
@@ -191,6 +193,78 @@ func TestBackupNow(t *testing.T) {
 			t.Fatalf("code = %d, want 400", w.Code)
 		}
 	})
+
+	// data-durability-9: an owner's backups are rationed per server; an admin's
+	// are not.
+	t.Run("owner inside the cooldown -> 429 backup_cooldown with Retry-After", func(t *testing.T) {
+		api, _, _, backuper := mk()
+		api.BackupCooldown = 10 * time.Minute
+		api.Now = time.Now // the fake stamps backup.create audits with the wall clock
+		api.External = staticExternal{p: owner}
+		if w := do(api.ExternalHandler(), "POST", path, "", nil); w.Code != http.StatusAccepted {
+			t.Fatalf("first backup: code = %d (%s)", w.Code, w.Body.String())
+		}
+		w := do(api.ExternalHandler(), "POST", path, "", nil)
+		if w.Code != http.StatusTooManyRequests || decodeErr(t, w) != "backup_cooldown" {
+			t.Fatalf("second backup: code = %d body %s", w.Code, w.Body.String())
+		}
+		if ra, _ := strconv.Atoi(w.Header().Get("Retry-After")); ra < 590 || ra > 600 {
+			t.Fatalf("Retry-After = %q, want about 600", w.Header().Get("Retry-After"))
+		}
+		if backuper.calls != 1 {
+			t.Fatalf("backuper called %d times, want 1", backuper.calls)
+		}
+	})
+
+	t.Run("cooldown elapsed -> 202", func(t *testing.T) {
+		api, repo, _, _ := mk()
+		api.BackupCooldown = 10 * time.Minute
+		api.Now = time.Now
+		repo.backupRequested = map[string]time.Time{"survival": time.Now().Add(-11 * time.Minute)}
+		api.External = staticExternal{p: owner}
+		if w := do(api.ExternalHandler(), "POST", path, "", nil); w.Code != http.StatusAccepted {
+			t.Fatalf("code = %d (%s)", w.Code, w.Body.String())
+		}
+	})
+
+	t.Run("admin bypasses the cooldown and the store cap", func(t *testing.T) {
+		api, repo, _, backuper := mk()
+		api.BackupCooldown = 10 * time.Minute
+		api.BackupStoreCap = 100
+		api.Now = time.Now
+		repo.backupRequested = map[string]time.Time{"survival": time.Now()}
+		repo.backups = []fakeBackup{{view: BackupView{ID: "b1", ServerName: "other", Status: "present", SizeBytes: 500}}}
+		api.External = staticExternal{p: &Principal{UserID: "admin1", Email: "admin1@example.net",
+			Role: "admin", ViaAdminAccess: true}}
+		if w := do(api.ExternalHandler(), "POST", path, "", nil); w.Code != http.StatusAccepted {
+			t.Fatalf("code = %d (%s)", w.Code, w.Body.String())
+		}
+		if backuper.calls != 1 {
+			t.Fatal("the admin's backup did not start")
+		}
+	})
+
+	t.Run("owner with the store at its cap -> 507 backup_store_full", func(t *testing.T) {
+		api, repo, _, backuper := mk()
+		api.BackupStoreCap = 1000
+		repo.backups = []fakeBackup{
+			{view: BackupView{ID: "b1", ServerName: "other", Status: "present", SizeBytes: 600}},
+			{view: BackupView{ID: "b2", ServerName: "survival", Status: "present", SizeBytes: 400}},
+			{view: BackupView{ID: "b3", ServerName: "survival", Status: "deleted", SizeBytes: 9000}},
+		}
+		api.External = staticExternal{p: owner}
+		w := do(api.ExternalHandler(), "POST", path, "", nil)
+		if w.Code != http.StatusInsufficientStorage || decodeErr(t, w) != "backup_store_full" {
+			t.Fatalf("code = %d body %s", w.Code, w.Body.String())
+		}
+		if backuper.calls != 0 {
+			t.Fatal("a full store still started a backup")
+		}
+		repo.backups[0].view.Status = "deleted"
+		if w := do(api.ExternalHandler(), "POST", path, "", nil); w.Code != http.StatusAccepted {
+			t.Fatalf("below the cap: code = %d (%s)", w.Code, w.Body.String())
+		}
+	})
 }
 
 // TestInternalBackup exercises POST /api/v1/internal/servers/{name}/backup, the
diff --git a/internal/api/handlers_backups.go b/internal/api/handlers_backups.go
index c57a013..015a9ba 100644
--- a/internal/api/handlers_backups.go
+++ b/internal/api/handlers_backups.go
@@ -1,9 +1,11 @@
 package api
 
 import (
+	"context"
 	"errors"
 	"net/http"
 	"strings"
+	"time"
 
 	"felis.lolicon.best/internal/apis/felis/v1alpha1"
 	"felis.lolicon.best/internal/maintenance"
@@ -255,10 +257,49 @@ func (a *API) handleBackupNow(w http.ResponseWriter, r *http.Request) {
 		writeError(w, r, errForbidden)
 		return
 	}
+	if !p.IsAdmin() {
+		if err := a.backupAllowance(r.Context(), name); err != nil {
+			writeError(w, r, err)
+			return
+		}
+	}
 
 	a.enqueueBackup(w, r, name, rec, auditActor(p), "external")
 }
 
+// backupAllowance rations an owner's on-demand backups (data-durability-9):
+// one per BackupCooldown per server, and none while the present backups fill
+// BackupStoreCap. The owner's older backups are pruned by the Job itself
+// ([archive] manual_keep), so these two gates bound the rate and the total.
+func (a *API) backupAllowance(ctx context.Context, name string) error {
+	if a.BackupCooldown > 0 {
+		now := a.now()
+		last, err := a.Repo.LastBackupRequest(ctx, name, now.Add(-a.BackupCooldown))
+		if err != nil {
+			return err
+		}
+		if !last.IsZero() {
+			wait := last.Add(a.BackupCooldown).Sub(now)
+			if wait > 0 {
+				return newError(http.StatusTooManyRequests, "backup_cooldown",
+					"a backup of this server was started %s ago; the next one can start in %s",
+					now.Sub(last).Round(time.Second), wait.Round(time.Second)).retryAfter(wait)
+			}
+		}
+	}
+	if a.BackupStoreCap > 0 {
+		used, err := a.Repo.BackupStoreBytes(ctx)
+		if err != nil {
+			return err
+		}
+		if used >= a.BackupStoreCap {
+			return newError(http.StatusInsufficientStorage, "backup_store_full",
+				"the backup store is full; ask an administrator to free space")
+		}
+	}
+	return nil
+}
+
 // handleInternalBackup is the internal-face backup trigger. The break-glass console
 // (root on the node, holding the service token) POSTs here to snapshot a stopped
 // world while felis-api is alive — it goes through the API rather than direct-to-CRD
diff --git a/internal/api/jobstatus_test.go b/internal/api/jobstatus_test.go
index 0e0d7ba..f9fb503 100644
--- a/internal/api/jobstatus_test.go
+++ b/internal/api/jobstatus_test.go
@@ -11,6 +11,9 @@ import (
 	batchv1 "k8s.io/api/batch/v1"
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
+	"sigs.k8s.io/controller-runtime/pkg/client/fake"
 )
 
 type fakeJobStatus struct {
@@ -145,3 +148,58 @@ func TestJobToAsyncJob(t *testing.T) {
 		t.Fatal("foreign job must be dropped")
 	}
 }
+
+// TestLatestJobsExplainsFailures: a failed Job reports the error its container
+// exited on (the last line of the terminated message), newest pod first, and
+// keeps the condition text when no pod explains it.
+func TestLatestJobsExplainsFailures(t *testing.T) {
+	scheme := runtime.NewScheme()
+	if err := clientgoscheme.AddToScheme(scheme); err != nil {
+		t.Fatal(err)
+	}
+	labels := func(job string) map[string]string {
+		return map[string]string{jobServerLabel: "survival", jobManagedByLabel: jobManagedByBackup, "job-name": job}
+	}
+	at := func(min int) metav1.Time { return metav1.NewTime(time.Date(2026, 9, 24, 10, min, 0, 0, time.UTC)) }
+	failedJob := func(name string, min int) *batchv1.Job {
+		start := at(min)
+		return &batchv1.Job{
+			ObjectMeta: metav1.ObjectMeta{Name: name, Namespace: "minecraft", Labels: labels(name)},
+			Status: batchv1.JobStatus{StartTime: &start, Conditions: []batchv1.JobCondition{{
+				Type: batchv1.JobFailed, Status: corev1.ConditionTrue,
+				Reason: "BackoffLimitExceeded", Message: "Job has reached the specified backoff limit",
+			}}},
+		}
+	}
+	pod := func(name, job string, min int, exit int32, msg string) *corev1.Pod {
+		return &corev1.Pod{
+			ObjectMeta: metav1.ObjectMeta{Name: name, Namespace: "minecraft", Labels: labels(job), CreationTimestamp: at(min)},
+			Status: corev1.PodStatus{ContainerStatuses: []corev1.ContainerStatus{{
+				Name: "backup", State: corev1.ContainerState{Terminated: &corev1.ContainerStateTerminated{ExitCode: exit, Message: msg}},
+			}}},
+		}
+	}
+	c := fake.NewClientBuilder().WithScheme(scheme).WithObjects(
+		failedJob("backup-survival-a", 1),
+		failedJob("backup-survival-b", 2),
+		pod("a-1", "backup-survival-a", 1, 1, "felis backup: first try\n"),
+		pod("a-2", "backup-survival-a", 3, 1,
+			"archiving survival\nfelis backup: backup: not enough free disk for the archive: the world is 2.0 GiB\n"),
+		pod("b-1", "backup-survival-b", 2, 0, "done"),
+	).Build()
+
+	jobs, err := NewK8sJobStatus(c, "minecraft").LatestJobs(context.Background(), "survival")
+	if err != nil {
+		t.Fatal(err)
+	}
+	got := map[string]string{}
+	for _, j := range jobs {
+		got[j.Name] = j.Message
+	}
+	if want := "felis backup: backup: not enough free disk for the archive: the world is 2.0 GiB"; got["backup-survival-a"] != want {
+		t.Errorf("a: message = %q, want %q", got["backup-survival-a"], want)
+	}
+	if want := "Job has reached the specified backoff limit"; got["backup-survival-b"] != want {
+		t.Errorf("b: message = %q, want the condition text", got["backup-survival-b"])
+	}
+}
diff --git a/internal/api/k8sjobstatus.go b/internal/api/k8sjobstatus.go
index 8dc3f66..aaff61d 100644
--- a/internal/api/k8sjobstatus.go
+++ b/internal/api/k8sjobstatus.go
@@ -3,6 +3,8 @@ package api
 import (
 	"context"
 	"sort"
+	"strings"
+	"time"
 
 	batchv1 "k8s.io/api/batch/v1"
 	corev1 "k8s.io/api/core/v1"
@@ -53,9 +55,66 @@ func (k *K8sJobStatus) LatestJobs(ctx context.Context, serverName string) ([]Asy
 	if len(out) > 20 {
 		out = out[:20]
 	}
+	k.explainFailures(ctx, serverName, out)
 	return out, nil
 }
 
+// explainFailures replaces a failed Job's condition text ("Job has reached the
+// specified backoff limit") with the error its container exited on. The
+// executors set TerminationMessagePolicy FallbackToLogsOnError, so the
+// terminated state carries the tail of the log, whose last line is the
+// "felis backup: …" / "felis restore: …" error. The pods carry the Job's
+// labels, so one list covers every Job of the server; a pod already collected
+// by the Job TTL, or a list error, leaves the condition text in place.
+func (k *K8sJobStatus) explainFailures(ctx context.Context, serverName string, jobs []AsyncJob) {
+	failed := map[string]int{}
+	for i, j := range jobs {
+		if j.State == "failed" {
+			failed[j.Name] = i
+		}
+	}
+	if len(failed) == 0 {
+		return
+	}
+	var pods corev1.PodList
+	if err := k.c.List(ctx, &pods, client.InNamespace(k.namespace),
+		client.MatchingLabels{jobServerLabel: serverName}); err != nil {
+		return
+	}
+	newest := map[string]time.Time{}
+	for i := range pods.Items {
+		pod := &pods.Items[i]
+		idx, ok := failed[pod.Labels["job-name"]]
+		if !ok {
+			continue
+		}
+		msg := lastTerminationLine(pod)
+		if msg == "" || !pod.CreationTimestamp.Time.After(newest[pod.Labels["job-name"]]) {
+			continue
+		}
+		newest[pod.Labels["job-name"]] = pod.CreationTimestamp.Time
+		jobs[idx].Message = msg
+	}
+}
+
+// lastTerminationLine returns the last non-empty line of the pod's terminated
+// container message, capped for display.
+func lastTerminationLine(pod *corev1.Pod) string {
+	for _, cs := range pod.Status.ContainerStatuses {
+		t := cs.State.Terminated
+		if t == nil || t.ExitCode == 0 {
+			continue
+		}
+		lines := strings.Split(strings.TrimSpace(t.Message), "\n")
+		line := strings.TrimSpace(lines[len(lines)-1])
+		if len(line) > 400 {
+			line = line[:400] + "…"
+		}
+		return line
+	}
+	return ""
+}
+
 // jobToAsyncJob projects one Job onto its kind/state/message. Complete condition →
 // succeeded, Failed → failed with its reason (Job conditions carry the generic
 // "backoff limit exceeded" text; the pod log holds the underlying error), anything
diff --git a/internal/api/pgrepo.go b/internal/api/pgrepo.go
index e236974..a1d9ec7 100644
--- a/internal/api/pgrepo.go
+++ b/internal/api/pgrepo.go
@@ -747,6 +747,28 @@ func (p *PGRepo) BackupByID(ctx context.Context, id string) (*BackupRecord, erro
 	return &b, nil
 }
 
+// LastBackupRequest reads the newest backup.create audit row for the server
+// since the given time; the created_at index bounds the scan to that window.
+func (p *PGRepo) LastBackupRequest(ctx context.Context, serverName string, since time.Time) (time.Time, error) {
+	var at sql.NullTime
+	err := p.db.QueryRowContext(ctx,
+		`SELECT max(created_at) FROM audit_logs
+		 WHERE created_at >= $2 AND action = 'backup.create' AND server_name = $1`,
+		serverName, since).Scan(&at)
+	if err != nil {
+		return time.Time{}, err
+	}
+	return at.Time, nil
+}
+
+// BackupStoreBytes sums size_bytes over the present world backups.
+func (p *PGRepo) BackupStoreBytes(ctx context.Context) (int64, error) {
+	var n int64
+	err := p.db.QueryRowContext(ctx,
+		`SELECT COALESCE(sum(size_bytes), 0) FROM world_backups WHERE status = 'present'`).Scan(&n)
+	return n, err
+}
+
 func (p *PGRepo) Audit(ctx context.Context, e AuditEntry) error {
 	// A nil Payload must land as SQL NULL, not the text "null"; a non-nil Payload is
 	// passed as a JSON text the jsonb column parses (same idiom as reaper.PGStore).
diff --git a/internal/api/repo.go b/internal/api/repo.go
index 5f5d661..41e65ab 100644
--- a/internal/api/repo.go
+++ b/internal/api/repo.go
@@ -297,6 +297,14 @@ type Repo interface {
 	// none matches. Like LatestBackup the returned BackupRecord carries the
 	// server-side backup_ref the restore path needs; the client never sees it.
 	BackupByID(ctx context.Context, id string) (*BackupRecord, error)
+	// LastBackupRequest returns when an on-demand backup of the server was last
+	// accepted (its newest backup.create audit row) at or after since, or the zero
+	// time when there was none. The since bound keeps the lookup inside the
+	// cooldown window the caller enforces.
+	LastBackupRequest(ctx context.Context, serverName string, since time.Time) (time.Time, error)
+	// BackupStoreBytes sums the sizes of every present world backup, the figure
+	// [archive] max_local_bytes caps.
+	BackupStoreBytes(ctx context.Context) (int64, error)
 	// SeedServer inserts the business-layer rows for a newly created server (spec
 	// §15): a servers row (owner_id NULL — claimed later, spec §9.3) and its
 	// subdomain alias, both idempotent. The resource cache (cpuMilli, memoryMB,
diff --git a/internal/backup/room.go b/internal/backup/room.go
new file mode 100644
index 0000000..415dca1
--- /dev/null
+++ b/internal/backup/room.go
@@ -0,0 +1,93 @@
+package backup
+
+import (
+	"errors"
+	"fmt"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"syscall"
+)
+
+// MinFreeAfter is the share of the archive filesystem an on-demand backup must
+// leave free. The archive store sits on the node's disk beside the worlds and
+// the database; below about a tenth free the kubelet starts evicting pods
+// (docs/troubleshooting.md §13b), so a backup that would cross it is refused.
+const MinFreeAfter = 0.10
+
+// ErrNoRoom is returned by CheckRoom when the archive would leave too little
+// free space.
+var ErrNoRoom = errors.New("backup: not enough free disk for the archive")
+
+// CheckRoom refuses an archive of srcDir into archiveDir that could push the
+// archive filesystem below minFree free. The world's uncompressed size stands
+// in for the archive's, which gzip only makes smaller. archiveDir need not
+// exist yet; its nearest existing parent is measured.
+func CheckRoom(archiveDir, srcDir string, minFree float64) error {
+	dir := archiveDir
+	for {
+		if _, err := os.Stat(dir); err == nil {
+			break
+		}
+		parent := filepath.Dir(dir)
+		if parent == dir {
+			return fmt.Errorf("backup: no existing directory above %s", archiveDir)
+		}
+		dir = parent
+	}
+	var st syscall.Statfs_t
+	if err := syscall.Statfs(dir, &st); err != nil {
+		return fmt.Errorf("backup: measure %s: %w", dir, err)
+	}
+	bsize := uint64(st.Bsize) // uint32 on darwin
+	total := uint64(st.Blocks) * bsize
+	avail := uint64(st.Bavail) * bsize
+	if total == 0 {
+		return nil
+	}
+	need, err := treeBytes(srcDir)
+	if err != nil {
+		return err
+	}
+	floor := uint64(float64(total) * minFree)
+	if avail < need || avail-need < floor {
+		return fmt.Errorf("%w: the world is %s and %s is free of %s, which would leave less than %.0f%% free",
+			ErrNoRoom, byteSize(need), byteSize(avail), byteSize(total), minFree*100)
+	}
+	return nil
+}
+
+// treeBytes sums the sizes of the regular files under dir.
+func treeBytes(dir string) (uint64, error) {
+	var n uint64
+	err := filepath.WalkDir(dir, func(_ string, d fs.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+		if d.Type().IsRegular() {
+			info, err := d.Info()
+			if err != nil {
+				return err
+			}
+			n += uint64(info.Size())
+		}
+		return nil
+	})
+	if err != nil {
+		return 0, fmt.Errorf("backup: measure the world: %w", err)
+	}
+	return n, nil
+}
+
+func byteSize(b uint64) string {
+	const unit = 1024
+	if b < unit {
+		return fmt.Sprintf("%d B", b)
+	}
+	div, exp := uint64(unit), 0
+	for n := b / unit; n >= unit; n /= unit {
+		div *= unit
+		exp++
+	}
+	return fmt.Sprintf("%.1f %ciB", float64(b)/float64(div), "KMGTPE"[exp])
+}
diff --git a/internal/backup/room_test.go b/internal/backup/room_test.go
new file mode 100644
index 0000000..9299084
--- /dev/null
+++ b/internal/backup/room_test.go
@@ -0,0 +1,26 @@
+package backup
+
+import (
+	"errors"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestCheckRoom(t *testing.T) {
+	src := t.TempDir()
+	if err := os.WriteFile(filepath.Join(src, "level.dat"), make([]byte, 4096), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	archives := filepath.Join(t.TempDir(), "not", "made", "yet")
+	if err := CheckRoom(archives, src, 0); err != nil {
+		t.Fatalf("no floor: %v", err)
+	}
+	// No disk is ever entirely free, so a 100% floor always refuses.
+	if err := CheckRoom(archives, src, 1); !errors.Is(err, ErrNoRoom) {
+		t.Fatalf("full floor: err = %v, want ErrNoRoom", err)
+	}
+	if err := CheckRoom(archives, filepath.Join(src, "absent"), 0); err == nil {
+		t.Fatal("a missing world measured as empty")
+	}
+}
diff --git a/internal/backupjob/jobspec.go b/internal/backupjob/jobspec.go
index d2db9a6..a30de17 100644
--- a/internal/backupjob/jobspec.go
+++ b/internal/backupjob/jobspec.go
@@ -159,6 +159,10 @@ func BackupJob(p JobParams) (*batchv1.Job, error) {
 		},
 	}
 
+	// The exit error reaches GET /servers/{name}/jobs through the terminated
+	// state (api.K8sJobStatus), in place of the Job's generic backoff text.
+	container.TerminationMessagePolicy = corev1.TerminationMessageFallbackToLogsOnError
+
 	name := p.JobName
 	if name == "" {
 		name = BackupJobName(p.Server)
diff --git a/internal/config/config.go b/internal/config/config.go
index 82695d7..764113c 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -220,13 +220,20 @@ type RegistryS3Config struct {
 }
 
 // ArchiveConfig is the [archive] table plus its [archive.s3] subtable (spec §19).
+// The manual_* keys bound the owners' on-demand backups, which share the
+// archive store with the reaper's: how long each is kept (default 30d), how
+// many per server (default 5, the oldest go first), and how soon an owner may
+// ask for the next one (default 10m). Empty or zero means the default.
 type ArchiveConfig struct {
-	Store         string          `toml:"store"`
-	LocalPath     string          `toml:"local_path"`
-	Retention     string          `toml:"retention"`
-	WarnBefore    []string        `toml:"warn_before"`
-	MaxLocalBytes string          `toml:"max_local_bytes"`
-	S3            ArchiveS3Config `toml:"s3"`
+	Store           string          `toml:"store"`
+	LocalPath       string          `toml:"local_path"`
+	Retention       string          `toml:"retention"`
+	WarnBefore      []string        `toml:"warn_before"`
+	MaxLocalBytes   string          `toml:"max_local_bytes"`
+	ManualRetention string          `toml:"manual_retention"`
+	ManualKeep      int             `toml:"manual_keep"`
+	ManualCooldown  string          `toml:"manual_cooldown"`
+	S3              ArchiveS3Config `toml:"s3"`
 }
 
 // ArchiveS3Config is the [archive.s3] subtable.
diff --git a/internal/pgint/reaper_test.go b/internal/pgint/reaper_test.go
index 7f66903..cc9ee87 100644
--- a/internal/pgint/reaper_test.go
+++ b/internal/pgint/reaper_test.go
@@ -5,9 +5,11 @@ package pgint
 import (
 	"context"
 	"database/sql"
+	"strings"
 	"testing"
 	"time"
 
+	"felis.lolicon.best/internal/api"
 	"felis.lolicon.best/internal/backup"
 	"felis.lolicon.best/internal/reaper"
 )
@@ -139,3 +141,95 @@ func TestReclaimRestartsReaperClock(t *testing.T) {
 		t.Fatalf("owner = %v, newest backup = %q; want released and %q", owner, newest, ar.archived[0])
 	}
 }
+
+// TestManualBackupRationing pins the SQL behind data-durability-9: keep-N
+// pruning picks a server's oldest on-demand backups, capacity eviction takes
+// on-demand backups before copied reaper archives and never offers the only
+// copy of a reaped world, and the API's cooldown and store-size reads see the
+// rows the rest of the platform writes.
+func TestManualBackupRationing(t *testing.T) {
+	ctx := context.Background()
+	st := reaper.NewPGStore(db)
+	name := "ration-" + suffix(t)
+	if _, err := db.ExecContext(ctx,
+		`INSERT INTO servers (name, cached_cpu_milli, cached_memory_mb, cached_storage_mb) VALUES ($1, 100, 128, 1)`,
+		name); err != nil {
+		t.Fatalf("seed server: %v", err)
+	}
+	storeBefore, err := repo.BackupStoreBytes(ctx)
+	if err != nil {
+		t.Fatalf("BackupStoreBytes: %v", err)
+	}
+
+	now := time.Now()
+	insert := func(id, reason string, created time.Time, offsite bool, size int64) {
+		t.Helper()
+		var offsiteAt any
+		if offsite {
+			offsiteAt = created
+		}
+		if _, err := db.ExecContext(ctx,
+			`INSERT INTO world_backups (id, server_name, backup_ref, size_bytes, reason, status, created_at, expires_at, offsite_at)
+			 VALUES ($1, $2, $3, $4, $5, 'present', $6, $7, $8)`,
+			id, name, "/archives/"+id+".tar.gz", size, reason, created, created.Add(90*reaper.Day), offsiteAt); err != nil {
+			t.Fatalf("seed %s: %v", id, err)
+		}
+	}
+	sfx := suffix(t)
+	var manual []string
+	for i := 0; i < 7; i++ {
+		id := "bk-m" + string(rune('0'+i)) + "-" + sfx
+		manual = append(manual, id)
+		insert(id, "manual", now.Add(time.Duration(i-7)*time.Hour), false, 10)
+	}
+	sole := "bk-sole-" + sfx
+	copied := "bk-copied-" + sfx
+	insert(sole, "inactive_15d", now.Add(-100*reaper.Day), false, 1000)
+	insert(copied, "inactive_15d", now.Add(-50*reaper.Day), true, 100)
+
+	excess, err := st.ExcessManualBackups(ctx, name, 5)
+	if err != nil {
+		t.Fatalf("ExcessManualBackups: %v", err)
+	}
+	if len(excess) != 2 || excess[0].ID != manual[0] || excess[1].ID != manual[1] {
+		t.Fatalf("excess = %+v; want the two oldest manual backups, oldest first", excess)
+	}
+
+	all, err := st.EvictableBackups(ctx)
+	if err != nil {
+		t.Fatalf("EvictableBackups: %v", err)
+	}
+	var got []string
+	for _, b := range all {
+		if b.ServerName == name {
+			got = append(got, b.ID)
+		}
+	}
+	want := append(append([]string{}, manual...), copied)
+	if strings.Join(got, ",") != strings.Join(want, ",") {
+		t.Fatalf("eviction order = %v\nwant %v (manual oldest first, then the copied archive, never the sole copy)", got, want)
+	}
+
+	storeAfter, err := repo.BackupStoreBytes(ctx)
+	if err != nil {
+		t.Fatalf("BackupStoreBytes: %v", err)
+	}
+	if storeAfter-storeBefore != 7*10+1000+100 {
+		t.Fatalf("store grew by %d, want %d", storeAfter-storeBefore, 7*10+1000+100)
+	}
+
+	if at, err := repo.LastBackupRequest(ctx, name, now.Add(-10*time.Minute)); err != nil || !at.IsZero() {
+		t.Fatalf("before any request: LastBackupRequest = (%v, %v)", at, err)
+	}
+	if err := repo.Audit(ctx, api.AuditEntry{Actor: "owner@example.net", Source: "external",
+		Action: "backup.create", ServerName: name}); err != nil {
+		t.Fatalf("Audit: %v", err)
+	}
+	at, err := repo.LastBackupRequest(ctx, name, time.Now().Add(-10*time.Minute))
+	if err != nil || at.IsZero() || time.Since(at) > time.Minute {
+		t.Fatalf("after a request: LastBackupRequest = (%v, %v)", at, err)
+	}
+	if at, err := repo.LastBackupRequest(ctx, name, time.Now().Add(time.Minute)); err != nil || !at.IsZero() {
+		t.Fatalf("a request before since still counted: (%v, %v)", at, err)
+	}
+}
diff --git a/internal/reaper/pgstore.go b/internal/reaper/pgstore.go
index fe272b0..50bebd6 100644
--- a/internal/reaper/pgstore.go
+++ b/internal/reaper/pgstore.go
@@ -106,14 +106,28 @@ func (s *PGStore) PresentBackupBytes(ctx context.Context) (int64, error) {
 	return n, err
 }
 
-func (s *PGStore) OldestPresentBackups(ctx context.Context) ([]StoredBackup, error) {
-	const q = `SELECT id, server_name, backup_ref, size_bytes FROM world_backups
-		WHERE status = 'present' ORDER BY created_at ASC`
+func (s *PGStore) EvictableBackups(ctx context.Context) ([]StoredBackup, error) {
+	const q = `SELECT id, server_name, backup_ref, size_bytes, reason FROM world_backups
+		WHERE status = 'present' AND (reason <> 'inactive_15d' OR offsite_at IS NOT NULL)
+		ORDER BY reason = 'inactive_15d', created_at ASC`
 	return s.queryBackups(ctx, q)
 }
 
+// ExcessManualBackups lists server's present on-demand backups beyond the
+// newest keep, oldest first: what the backup Job removes after adding one.
+func (s *PGStore) ExcessManualBackups(ctx context.Context, server string, keep int) ([]StoredBackup, error) {
+	const q = `SELECT id, server_name, backup_ref, size_bytes, reason FROM world_backups
+		WHERE server_name = $1 AND status = 'present' AND reason = 'manual'
+		ORDER BY created_at DESC OFFSET $2`
+	out, err := s.queryBackups(ctx, q, server, keep)
+	for i, j := 0, len(out)-1; i < j; i, j = i+1, j-1 {
+		out[i], out[j] = out[j], out[i]
+	}
+	return out, err
+}
+
 func (s *PGStore) ListExpiredBackups(ctx context.Context, now time.Time) ([]StoredBackup, error) {
-	const q = `SELECT id, server_name, backup_ref, size_bytes FROM world_backups
+	const q = `SELECT id, server_name, backup_ref, size_bytes, reason FROM world_backups
 		WHERE status = 'present' AND expires_at < $1 ORDER BY expires_at ASC`
 	return s.queryBackups(ctx, q, now)
 }
@@ -127,7 +141,7 @@ func (s *PGStore) queryBackups(ctx context.Context, q string, args ...any) ([]St
 	var out []StoredBackup
 	for rows.Next() {
 		var b StoredBackup
-		if err := rows.Scan(&b.ID, &b.ServerName, &b.BackupRef, &b.SizeBytes); err != nil {
+		if err := rows.Scan(&b.ID, &b.ServerName, &b.BackupRef, &b.SizeBytes, &b.Reason); err != nil {
 			return nil, err
 		}
 		out = append(out, b)
diff --git a/internal/reaper/reaper.go b/internal/reaper/reaper.go
index 91cdd38..6398c7a 100644
--- a/internal/reaper/reaper.go
+++ b/internal/reaper/reaper.go
@@ -81,6 +81,16 @@ type Config struct {
 	WarnBefore     []time.Duration // §24: warn these long before the deadline (default 3d, 1d)
 	Retention      time.Duration   // §18: keep a backup this long after deletion (default 3mo≈90d)
 	MaxLocalBytes  int64           // §26: backup store soft cap; 0 = unlimited
+	// ManualRetention is how long an owner's on-demand backup is kept; it is
+	// a restore point for a world that still exists, so it goes sooner than a
+	// reaped world's only archive (default 30d).
+	ManualRetention time.Duration
+	// ManualKeep caps the on-demand backups kept per server; the backup Job
+	// removes the oldest beyond it (default 5).
+	ManualKeep int
+	// ManualCooldown is the shortest gap between two owner-requested backups
+	// of one server (default 10m); operators are not held to it.
+	ManualCooldown time.Duration
 	// RequireOffsite holds each deletion until the world's archive has its
 	// off-site copy ([offsite] configured; internal/offsite records the copy).
 	// The archive is written on the run that finds the world idle, and the
@@ -96,6 +106,10 @@ func DefaultConfig() Config {
 		WarnBefore:     []time.Duration{3 * Day, 1 * Day},
 		Retention:      90 * Day,
 		MaxLocalBytes:  0,
+
+		ManualRetention: 30 * Day,
+		ManualKeep:      5,
+		ManualCooldown:  10 * time.Minute,
 	}
 }
 
@@ -151,6 +165,7 @@ type StoredBackup struct {
 	ServerName string
 	BackupRef  string
 	SizeBytes  int64
+	Reason     string
 }
 
 // AuditRecord is a reaper-sourced audit_logs entry. The PG binding fills
@@ -190,9 +205,12 @@ type Store interface {
 	// PresentBackupBytes is the total size of status=present backups (§26 cap).
 	PresentBackupBytes(ctx context.Context) (int64, error)
 
-	// OldestPresentBackups lists status=present backups oldest-first, for
-	// early eviction when the store is full.
-	OldestPresentBackups(ctx context.Context) ([]StoredBackup, error)
+	// EvictableBackups lists the status=present backups that may go before
+	// their expiry when the store is full, in eviction order: on-demand
+	// backups first, then reaper archives that have an off-site copy, oldest
+	// first within each. A reaper archive without an off-site copy is the only
+	// copy of a deleted world and is never listed.
+	EvictableBackups(ctx context.Context) ([]StoredBackup, error)
 
 	// ListExpiredBackups lists status=present backups whose expires_at < now.
 	ListExpiredBackups(ctx context.Context, now time.Time) ([]StoredBackup, error)
@@ -450,10 +468,10 @@ func (r *Reaper) ensureCapacity(ctx context.Context, now time.Time, sum *Summary
 	if used < r.Cfg.MaxLocalBytes {
 		return true, nil
 	}
-	r.log().Warn("reaper: backup store at capacity, evicting oldest backups early",
+	r.log().Warn("reaper: backup store at capacity, evicting on-demand and off-site-copied backups early",
 		"used", used, "max", r.Cfg.MaxLocalBytes)
 
-	old, err := r.Store.OldestPresentBackups(ctx)
+	old, err := r.Store.EvictableBackups(ctx)
 	if err != nil {
 		return false, err
 	}
@@ -474,6 +492,11 @@ func (r *Reaper) ensureCapacity(ctx context.Context, now time.Time, sum *Summary
 		}
 		used -= b.SizeBytes
 		sum.EvictedEarly++
+		r.log().Warn("reaper: backup evicted early", "id", b.ID, "server", b.ServerName, "reason", b.Reason, "bytes", b.SizeBytes)
+	}
+	if used >= r.Cfg.MaxLocalBytes {
+		r.log().Error("reaper: backup store still full; what remains are the only copies of reaped worlds, kept until they expire",
+			"used", used, "max", r.Cfg.MaxLocalBytes)
 	}
 	return used < r.Cfg.MaxLocalBytes, nil
 }
diff --git a/internal/reaper/reaper_test.go b/internal/reaper/reaper_test.go
index 95c5b46..661bf36 100644
--- a/internal/reaper/reaper_test.go
+++ b/internal/reaper/reaper_test.go
@@ -193,17 +193,22 @@ func (s *fakeStore) PresentBackupBytes(context.Context) (int64, error) {
 	return total, nil
 }
 
-func (s *fakeStore) OldestPresentBackups(context.Context) ([]StoredBackup, error) {
+func (s *fakeStore) EvictableBackups(context.Context) ([]StoredBackup, error) {
 	var ps []*fakeBackup
 	for _, b := range s.backups {
-		if b.status == "present" {
+		if b.status == "present" && (b.reason != ReasonInactive || b.offsite) {
 			ps = append(ps, b)
 		}
 	}
-	sort.Slice(ps, func(i, j int) bool { return ps[i].createdAt.Before(ps[j].createdAt) })
+	sort.SliceStable(ps, func(i, j int) bool {
+		if ri, rj := ps[i].reason == ReasonInactive, ps[j].reason == ReasonInactive; ri != rj {
+			return rj
+		}
+		return ps[i].createdAt.Before(ps[j].createdAt)
+	})
 	out := make([]StoredBackup, 0, len(ps))
 	for _, b := range ps {
-		out = append(out, StoredBackup{ID: b.id, ServerName: b.server, BackupRef: b.ref, SizeBytes: b.size})
+		out = append(out, StoredBackup{ID: b.id, ServerName: b.server, BackupRef: b.ref, SizeBytes: b.size, Reason: b.reason})
 	}
 	return out, nil
 }
@@ -623,8 +628,8 @@ func TestCapacityEvictsOldestThenReaps(t *testing.T) {
 		Candidate{Name: "epsilon", OwnerID: "user-5", LastActiveAt: idleBy(20 * Day)})
 	// Two present backups of 75 each = 150 > 100. Oldest must be evicted first.
 	st.backups = []*fakeBackup{
-		{id: "old", server: "zzz", ref: "ref-old", size: 75, status: "present", createdAt: idleBy(40 * Day), expires: testNow.Add(30 * Day)},
-		{id: "new", server: "yyy", ref: "ref-new", size: 75, status: "present", createdAt: idleBy(5 * Day), expires: testNow.Add(60 * Day)},
+		{id: "old", server: "zzz", ref: "ref-old", reason: "manual", size: 75, status: "present", createdAt: idleBy(40 * Day), expires: testNow.Add(30 * Day)},
+		{id: "new", server: "yyy", ref: "ref-new", reason: "manual", size: 75, status: "present", createdAt: idleBy(5 * Day), expires: testNow.Add(60 * Day)},
 	}
 
 	sum := mustRun(t, r)
@@ -669,7 +674,7 @@ func TestCapacityStillFullSkipsReap(t *testing.T) {
 	r, st, cl, ar := newReaper(cfg,
 		Candidate{Name: "zeta", OwnerID: "user-6", LastActiveAt: idleBy(20 * Day)})
 	st.backups = []*fakeBackup{
-		{id: "stuck", server: "zzz", ref: "ref-stuck", size: 150, status: "present", createdAt: idleBy(40 * Day), expires: testNow.Add(30 * Day)},
+		{id: "stuck", server: "zzz", ref: "ref-stuck", reason: "manual", size: 150, status: "present", createdAt: idleBy(40 * Day), expires: testNow.Add(30 * Day)},
 	}
 	// The archive backend can't delete, so eviction cannot free space.
 	r.Archiver.(*fakeArchiver).deleteErr = errors.New("evict unavailable")
@@ -689,6 +694,50 @@ func TestCapacityStillFullSkipsReap(t *testing.T) {
 	}
 }
 
+// Eviction order: on-demand backups go first, then reaper archives that have an
+// off-site copy; the only copy of a reaped world is never evicted early, even
+// when that leaves the store full and the idle world waits.
+func TestCapacityEvictionOrderSparesSoleCopies(t *testing.T) {
+	cfg := DefaultConfig()
+	cfg.MaxLocalBytes = 100
+	r, st, _, _ := newReaper(cfg,
+		Candidate{Name: "theta", OwnerID: "user-8", LastActiveAt: idleBy(20 * Day)})
+	st.backups = []*fakeBackup{
+		{id: "sole", server: "gone1", ref: "ref-sole", reason: ReasonInactive, size: 60, status: "present", createdAt: idleBy(80 * Day), expires: testNow.Add(10 * Day)},
+		{id: "copied", server: "gone2", ref: "ref-copied", reason: ReasonInactive, offsite: true, size: 30, status: "present", createdAt: idleBy(70 * Day), expires: testNow.Add(20 * Day)},
+		{id: "man", server: "live", ref: "ref-man", reason: "manual", size: 30, status: "present", createdAt: idleBy(2 * Day), expires: testNow.Add(28 * Day)},
+	}
+	sum := mustRun(t, r)
+	status := map[string]string{}
+	for _, b := range st.backups {
+		status[b.id] = b.status
+	}
+	// 120 over a cap of 100: the on-demand backup (30) alone brings it to 90.
+	if status["man"] != "deleted" || status["copied"] != "present" || status["sole"] != "present" {
+		t.Fatalf("evicted %v; want only the on-demand backup", status)
+	}
+	if sum.EvictedEarly != 1 || sum.WorldsReaped != 1 {
+		t.Fatalf("summary = %+v, want 1 evicted, 1 reaped", sum)
+	}
+
+	// Over a cap of 50 with only reaper archives left: the copied one goes,
+	// the sole copy stays, the store is still full, and the idle world waits.
+	cfg.MaxLocalBytes = 50
+	r2, st2, cl2, _ := newReaper(cfg,
+		Candidate{Name: "iota", OwnerID: "user-9", LastActiveAt: idleBy(20 * Day)})
+	st2.backups = []*fakeBackup{
+		{id: "sole", server: "gone1", ref: "ref-sole", reason: ReasonInactive, size: 60, status: "present", createdAt: idleBy(80 * Day), expires: testNow.Add(10 * Day)},
+		{id: "copied", server: "gone2", ref: "ref-copied", reason: ReasonInactive, offsite: true, size: 30, status: "present", createdAt: idleBy(70 * Day), expires: testNow.Add(20 * Day)},
+	}
+	sum2 := mustRun(t, r2)
+	if st2.backups[0].status != "present" || st2.backups[1].status != "deleted" {
+		t.Fatalf("sole=%s copied=%s, want present/deleted", st2.backups[0].status, st2.backups[1].status)
+	}
+	if sum2.StoreFull != 1 || sum2.WorldsReaped != 0 || cl2.deletePVCCalls != 0 {
+		t.Fatalf("summary = %+v, deletes = %d: the world should wait while the store is full", sum2, cl2.deletePVCCalls)
+	}
+}
+
 // Retention pass: backups past expires_at are deleted from the backend and
 // marked deleted; unexpired backups are untouched.
 func TestExpiredBackupsDeleted(t *testing.T) {
diff --git a/internal/restore/jobspec.go b/internal/restore/jobspec.go
index 4123de7..6548f38 100644
--- a/internal/restore/jobspec.go
+++ b/internal/restore/jobspec.go
@@ -138,6 +138,10 @@ func RestoreJob(p JobParams) (*batchv1.Job, error) {
 		},
 	}
 
+	// The exit error reaches GET /servers/{name}/jobs through the terminated
+	// state (api.K8sJobStatus), in place of the Job's generic backoff text.
+	container.TerminationMessagePolicy = corev1.TerminationMessageFallbackToLogsOnError
+
 	job := &batchv1.Job{
 		ObjectMeta: metav1.ObjectMeta{
 			Name:      RestoreJobName(p.Server),
diff --git a/panel/src/i18n/resources/en-US/backups.json b/panel/src/i18n/resources/en-US/backups.json
index f1d56c9..66fcb10 100644
--- a/panel/src/i18n/resources/en-US/backups.json
+++ b/panel/src/i18n/resources/en-US/backups.json
@@ -5,7 +5,7 @@
   "not_yours_title": "No permission to access backups",
   "not_yours_body": "Only the owner or an admin can view and restore this server's backups.",
   "latest_title": "Latest backup",
-  "history_note": "Historical backups can be used for restore before they expire. They are automatically cleaned up when they expire.",
+  "history_note": "Backups can be restored until they expire, then they are cleaned up automatically. Each server keeps only its most recent manual backups; older manual backups are removed once a new one finishes.",
   "reason_inactive": "Idle archive",
   "reason_manual": "Manual backup",
   "reason_label": "Reason: {{reason}}",
diff --git a/panel/src/i18n/resources/en-US/errors.json b/panel/src/i18n/resources/en-US/errors.json
index 4f18177..5f74283 100644
--- a/panel/src/i18n/resources/en-US/errors.json
+++ b/panel/src/i18n/resources/en-US/errors.json
@@ -19,6 +19,8 @@
   "not_stopped": "Stop the server completely before restoring — a restore overwrites the live world volume.",
   "maintenance_in_progress": "This server's world is busy with a restore, backup or file write — try again once it finishes, usually within a minute or two.",
   "no_world_volume": "This server has no world volume yet — start it once so it is created, then retry.",
+  "backup_cooldown": "This server was backed up moments ago, and manual backups have a cooldown — try again in a few minutes.",
+  "backup_store_full": "The backup store is full, so manual backups are paused — ask an administrator to free space.",
   "restore_unavailable": "Restore isn't available right now — try again later.",
   "session_expired": "Your session expired — please sign in again.",
   "forbidden": "You are not allowed to do that.",
diff --git a/panel/src/i18n/resources/zh-CN/backups.json b/panel/src/i18n/resources/zh-CN/backups.json
index 686ebda..a33795e 100644
--- a/panel/src/i18n/resources/zh-CN/backups.json
+++ b/panel/src/i18n/resources/zh-CN/backups.json
@@ -5,7 +5,7 @@
   "not_yours_title": "无权访问备份",
   "not_yours_body": "只有所有者或管理员才能查看并恢复该服务器的备份。",
   "latest_title": "最新备份",
-  "history_note": "历史备份在过期前均可用于恢复。到期后系统会自动清理，无需手动删除或管理。",
+  "history_note": "历史备份在过期前均可用于恢复，到期后自动清理。手动备份每台服务器只保留最近几份，新备份完成后会自动删除更早的手动备份。",
   "reason_inactive": "闲置自动回收",
   "reason_manual": "手动备份",
   "reason_label": "原因：{{reason}}",
diff --git a/panel/src/i18n/resources/zh-CN/errors.json b/panel/src/i18n/resources/zh-CN/errors.json
index fe78f58..63a85a3 100644
--- a/panel/src/i18n/resources/zh-CN/errors.json
+++ b/panel/src/i18n/resources/zh-CN/errors.json
@@ -19,6 +19,8 @@
   "not_stopped": "回档会覆盖世界的实时存储卷，请先把服务器完全停止再回档。",
   "maintenance_in_progress": "这台服务器的世界正在回档、备份或写入文件——等它完成后再试，通常不超过一两分钟。",
   "no_world_volume": "这台服务器还没有世界卷——先启动一次让它创建，然后再试。",
+  "backup_cooldown": "这台服务器刚备份过，手动备份之间有冷却时间——请过几分钟再试。",
+  "backup_store_full": "备份存储已满，暂时无法手动备份——请联系管理员清理空间。",
   "restore_unavailable": "回档功能当前不可用，请稍后再试。",
   "session_expired": "会话已过期——请重新登录。",
   "forbidden": "你无权执行此操作。",
diff --git a/panel/src/lib/api.test.ts b/panel/src/lib/api.test.ts
index 5796993..e1fc633 100644
--- a/panel/src/lib/api.test.ts
+++ b/panel/src/lib/api.test.ts
@@ -390,6 +390,12 @@ describe("api access-control wire shapes", () => {
     expect(humanizeError({ code: "not_running" })).toMatch(/running|wake/i);
     expect(humanizeError({ code: "console_unavailable" })).toMatch(/console/i);
   });
+
+  it("maps the backup rationing codes to their own copy", async () => {
+    const { humanizeError } = await import("./api");
+    expect(humanizeError({ code: "backup_cooldown" })).toMatch(/cooldown/i);
+    expect(humanizeError({ code: "backup_store_full" })).toMatch(/store is full/i);
+  });
 });
 
 describe("image whitelist and builds wire shapes", () => {
diff --git a/panel/src/lib/api.ts b/panel/src/lib/api.ts
index 73f98a9..ebb5c94 100644
--- a/panel/src/lib/api.ts
+++ b/panel/src/lib/api.ts
@@ -739,6 +739,12 @@ export function humanizeError(e: unknown): string {
       return t("maintenance_in_progress");
     case "no_world_volume":
       return t("no_world_volume");
+    // On-demand backup rationing (data-durability-9): one per server per
+    // cooldown, none while the shared backup store is at its cap.
+    case "backup_cooldown":
+      return t("backup_cooldown");
+    case "backup_store_full":
+      return t("backup_store_full");
     case "restore_unavailable":
       return t("restore_unavailable");
     // Server create/edit (spec §22): the portability regex + reservation list are