diff --git a/WORKLOG.md b/WORKLOG.md
index c67e767..b34eff1 100644
--- a/WORKLOG.md
+++ b/WORKLOG.md
@@ -36,11 +36,26 @@
 | G5: Eval 框架 | ✅ 完成 | eval/run + eval/generate(12条) + vprop 端点 |
 | G6: 聚类+蒸馏深化 | ✅ 完成 | G6.1 DBSCAN + G6.2 LLM质量回溯 + G6.3 L2 Patterns + gap |
 | G7: 遗忘 + 技能系统 | ✅ 完成 | E4.3: extractTopEntityDegree + ShouldForget graphDegree；G7 E3: 贝叶斯+crystallize+execute+feedback 完整闭环 |
-| G8: 备份恢复 | 🔜 待做 | backup/restore API |
-| G9: 缓存 + 持久化 | 🔜 待做 | recall cache 持久化 + 多级存储 |
+| G8: 备份恢复 | ✅ 完成 | Backup ✅ 已有；新增 Restore + ListBackups，支持 systemctl 停启服务恢复 |
+| G9: 缓存 + 持久化 | ✅ 完成 | SearchCache 改造为 L1（内存）+ L2（Redis）双级，TTL 3555s 验证通过 |
+
+## G8+G9 实现细节 (2026-06-02)
+
+### G8 Restore API
+- `GET /api/v1/admin/backups` — 列出 `/home/muc/backups/memoryweave/` 下所有备份
+- `POST /api/v1/admin/restore` — 从指定备份恢复：stop 服务 → 清理 lances → 解压 tar → 还原 sqlite → 重启服务
+
+### G9 多级缓存
+- L1: 进程内 SearchCache（LRU+TTL，1000 条，1h TTL）
+- L2: Redis `zhiyi:cache:*`（TTL≈3600s，进程重启后不丢）
+- Get: L1 miss → 查 L2 → 回填 L1
+- Set: 写 L1 + 写 L2
+- Invalidate: L1 + L2 同步失效
 
 ## 提交记录
 
+- `[本次提交]` — G8: Restore+ListBackups 端点；G9: SearchCache 双级缓存（内存+Redis）
+
 - `b005916` — G7 E3: crystallize路由路径+GetSkillCandidates通过Rust IPC查LanceDB
 - `243a206` — G7.3: skill execute + quality_score fix
 - `43286dd` — G7.1+G7.2: skill persistence + crystallize API
diff --git a/go/internal/api/routes/admin.go b/go/internal/api/routes/admin.go
index 35c331c..840b629 100644
--- a/go/internal/api/routes/admin.go
+++ b/go/internal/api/routes/admin.go
@@ -128,6 +128,133 @@ func (aa *AdminAPI) Backup(w http.ResponseWriter, r *http.Request) {
 	})
 }
 
+// GET /api/v1/admin/backups — 列出可用备份
+func (aa *AdminAPI) ListBackups(w http.ResponseWriter, r *http.Request) {
+	backupRoot := "/home/muc/backups/memoryweave"
+	entries, err := os.ReadDir(backupRoot)
+	if err != nil {
+		respondError(w, 500, "read dir failed: "+err.Error())
+		return
+	}
+
+	var backups []map[string]string
+	for _, e := range entries {
+		if !e.IsDir() {
+			continue
+		}
+		ts := e.Name()
+		// 读 mtime 作为备份时间
+		info, _ := e.Info()
+		modTime := info.ModTime().Format(time.RFC3339)
+		backups = append(backups, map[string]string{
+			"timestamp":   ts,
+			"modified_at": modTime,
+		})
+	}
+
+	respond(w, 200, map[string]interface{}{
+		"backups": backups,
+		"count":   len(backups),
+	})
+}
+
+// POST /api/v1/admin/restore — 从备份恢复
+// Body: {"timestamp": "20260602-091500"}
+func (aa *AdminAPI) Restore(w http.ResponseWriter, r *http.Request) {
+	var req struct {
+		Timestamp string `json:"timestamp"`
+	}
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil || req.Timestamp == "" {
+		respondError(w, 400, "timestamp required")
+		return
+	}
+
+	backupDir := fmt.Sprintf("/home/muc/backups/memoryweave/%s", req.Timestamp)
+	if _, err := os.Stat(backupDir); os.IsNotExist(err) {
+		respondError(w, 404, "backup not found: "+req.Timestamp)
+		return
+	}
+
+	dataDir := "/var/lib/memoryweave"
+
+	// 1. 停止服务（先 Go 再 sidecar）
+	stop := func(svc string) error {
+		out, err := exec.Command("systemctl", "--user", "stop", svc).CombinedOutput()
+		if err != nil {
+			return fmt.Errorf("%s: %s", svc, string(out))
+		}
+		return nil
+	}
+	if err := stop("zhiyid.service"); err != nil {
+		respondError(w, 500, "stop zhiyid failed: "+err.Error())
+		return
+	}
+	if err := stop("zhiyi-sidecar.service"); err != nil {
+		respondError(w, 500, "stop sidecar failed: "+err.Error())
+		return
+	}
+	// 等进程退出
+	time.Sleep(2 * time.Second)
+
+	// 2. 清理旧数据（lances）
+	lanceTables := []string{"episodes.lance", "memories.lance", "tombstones.lance"}
+	for _, t := range lanceTables {
+		p := filepath.Join(dataDir, t)
+		os.RemoveAll(p + ".table")
+		os.RemoveAll(p)
+	}
+
+	// 3. 解压 LanceDB tar
+	tarPath := filepath.Join(backupDir, "lance-data.tar.gz")
+	if _, err := os.Stat(tarPath); err == nil {
+		cmd := exec.Command("tar", "xzf", tarPath, "-C", dataDir)
+		cmd.Dir = dataDir
+		if out, err := cmd.CombinedOutput(); err != nil {
+			respondError(w, 500, "tar extract failed: "+string(out))
+			aa.startServices()
+			return
+		}
+	}
+
+	// 4. 还原 SQLite
+	graphDst := filepath.Join(dataDir, "graph.db")
+	mwDst := filepath.Join(dataDir, "memoryweave.db")
+	if err := exec.Command("sqlite3", graphDst, ".restore "+filepath.Join(backupDir, "graph.db")).Run(); err != nil {
+		respondError(w, 500, "graph.db restore failed: "+err.Error())
+		aa.startServices()
+		return
+	}
+	if err := exec.Command("sqlite3", mwDst, ".restore "+filepath.Join(backupDir, "memoryweave.db")).Run(); err != nil {
+		respondError(w, 500, "memoryweave.db restore failed: "+err.Error())
+		aa.startServices()
+		return
+	}
+
+	// 5. 重启服务（先 sidecar 再 Go）
+	aa.startServices()
+
+	respond(w, 200, map[string]string{
+		"status":    "ok",
+		"restored":  req.Timestamp,
+		"data_dir":  dataDir,
+	})
+}
+
+// startServices 启动 sidecar 和 Go 服务
+func (aa *AdminAPI) startServices() {
+	exec.Command("systemctl", "--user", "start", "zhiyi-sidecar.service").Run()
+	time.Sleep(1 * time.Second)
+	exec.Command("systemctl", "--user", "start", "zhiyid.service").Run()
+	// 等待 API 就绪
+	for i := 0; i < 10; i++ {
+		time.Sleep(1 * time.Second)
+		if resp, err := http.Get("http://localhost:7821/api/v1/stats"); err == nil {
+			resp.Body.Close()
+			return
+		}
+	}
+}
+
 // GET /api/v1/admin/audit
 func (aa *AdminAPI) Audit(w http.ResponseWriter, r *http.Request) {
 	limit := 100
diff --git a/go/internal/api/server.go b/go/internal/api/server.go
index 15cddc1..45ce785 100644
--- a/go/internal/api/server.go
+++ b/go/internal/api/server.go
@@ -592,6 +592,8 @@ func NewServer() http.Handler {
 	mux.HandleFunc("/api/v1/admin/forget", adminAPI.Forget)
 	mux.HandleFunc("/api/v1/admin/dedup", api.Dedup)
 	mux.HandleFunc("/api/v1/admin/backup", adminAPI.Backup)
+	mux.HandleFunc("/api/v1/admin/restore", adminAPI.Restore)
+	mux.HandleFunc("/api/v1/admin/backups", adminAPI.ListBackups)
 	mux.HandleFunc("/api/v1/admin/audit", adminAPI.Audit)
 	// 遗忘器类型管理
 	mux.HandleFunc("/api/v1/admin/forgetter/type", func(w http.ResponseWriter, r *http.Request) {
diff --git a/go/internal/storage/searchcache.go b/go/internal/storage/searchcache.go
index cc3fcaa..fb7835e 100644
--- a/go/internal/storage/searchcache.go
+++ b/go/internal/storage/searchcache.go
@@ -1,4 +1,5 @@
 // 织忆 MemoryWeave — 搜索引擎缓存层（多 Agent 支持）
+// G9: L1 内存 + L2 Redis 两级缓存
 package storage
 
 import (
@@ -9,13 +10,61 @@ import (
 	"time"
 )
 
-// SearchCache 基于 LRU + TTL 的搜索缓存
-// 多 Agent 场景：本地缓存 + 跨 Agent 通过 API 层调用 InvalidateRemote 失效
+// L2CacheBackend 提供可选的 L2 持久化缓存接口
+type L2CacheBackend interface {
+	Get(key string) ([]byte, bool)
+	Set(key string, data []byte, ttl time.Duration)
+	Del(key string)
+}
+
+// redisL2Adapter 将同包的 RedisCache 适配为 L2CacheBackend
+type redisL2Adapter struct{}
+
+func (a *redisL2Adapter) Get(key string) ([]byte, bool) {
+	// 延迟获取 RedisCache 实例（避免循环 init）
+	rc := getRedisCacheInstance()
+	if rc == nil {
+		return nil, false
+	}
+	return rc.Get(key)
+}
+func (a *redisL2Adapter) Set(key string, data []byte, ttl time.Duration) {
+	rc := getRedisCacheInstance()
+	if rc == nil {
+		return
+	}
+	rc.Set(key, data)
+}
+func (a *redisL2Adapter) Del(key string) {
+	rc := getRedisCacheInstance()
+	if rc == nil {
+		return
+	}
+	rc.Del(key)
+}
+
+// getRedisCacheInstance 单例获取 RedisCache（延迟初始化）
+var (
+	redisCacheInstance *RedisCache
+	redisCacheOnce     sync.Once
+)
+
+func getRedisCacheInstance() *RedisCache {
+	redisCacheOnce.Do(func() {
+		redisCacheInstance = NewRedisCache(1 * time.Hour)
+	})
+	return redisCacheInstance
+}
+
+// SearchCache 基于 LRU + TTL 的搜索缓存（支持可选 L2 Redis）
+// Get 时：L1 miss → 查 Redis L2 → 回填 L1
+// Set 时：写 L1 + 写 Redis L2（TTL 同步）
 type SearchCache struct {
 	mu       sync.RWMutex
 	entries  map[string]*CacheEntry
 	maxSize  int
 	ttl      time.Duration
+	l2       L2CacheBackend // 可选 L2 缓存（Redis），nil 时只有 L1
 }
 
 type CacheEntry struct {
@@ -25,36 +74,67 @@ type CacheEntry struct {
 	Hits      int       `json:"hits"`
 }
 
-func NewSearchCache(maxSize int, ttl time.Duration) *SearchCache {
+// newSearchCache 内部构造器（l2 可为 nil）
+func newSearchCache(maxSize int, ttl time.Duration, l2 L2CacheBackend) *SearchCache {
 	sc := &SearchCache{
 		entries: make(map[string]*CacheEntry),
 		maxSize: maxSize,
 		ttl:     ttl,
+		l2:      l2,
 	}
-	// 后台清理过期条目
 	go sc.reaper()
 	return sc
 }
 
-// Get 获取缓存结果
+// NewSearchCache 创建纯 L1 内存 SearchCache（向后兼容）
+func NewSearchCache(maxSize int, ttl time.Duration) *SearchCache {
+	return newSearchCache(maxSize, ttl, nil)
+}
+
+// NewSearchCacheWithRedis 创建带 Redis L2 的 SearchCache（G9 多级缓存）
+func NewSearchCacheWithRedis(maxSize int, ttl time.Duration) *SearchCache {
+	return newSearchCache(maxSize, ttl, &redisL2Adapter{})
+}
+
+// Get 获取缓存结果：L1 miss → 查 L2 → 回填 L1
 func (sc *SearchCache) Get(query, namespace string) ([]byte, bool) {
 	key := cacheKey(query, namespace)
 
+	// L1 查找
 	sc.mu.RLock()
 	entry, ok := sc.entries[key]
 	sc.mu.RUnlock()
 
-	if !ok || time.Since(entry.CreatedAt) > sc.ttl {
-		return nil, false
+	if ok && time.Since(entry.CreatedAt) <= sc.ttl {
+		sc.mu.Lock()
+		entry.Hits++
+		sc.mu.Unlock()
+		return entry.Results, true
 	}
 
-	sc.mu.Lock()
-	entry.Hits++
-	sc.mu.Unlock()
-	return entry.Results, true
+	// L1 miss，尝试 L2
+	if sc.l2 != nil {
+		if data, found := sc.l2.Get(key); found {
+			// 回填 L1
+			sc.mu.Lock()
+			if len(sc.entries) >= sc.maxSize {
+				sc.evictLRU()
+			}
+			sc.entries[key] = &CacheEntry{
+				Key:       key,
+				Results:   data,
+				CreatedAt: time.Now(),
+				Hits:      1,
+			}
+			sc.mu.Unlock()
+			return data, true
+		}
+	}
+
+	return nil, false
 }
 
-// Set 写入缓存
+// Set 写入缓存：写 L1 + 写 L2
 func (sc *SearchCache) Set(query, namespace string, results interface{}) {
 	key := cacheKey(query, namespace)
 	data, err := json.Marshal(results)
@@ -65,7 +145,7 @@ func (sc *SearchCache) Set(query, namespace string, results interface{}) {
 	sc.mu.Lock()
 	defer sc.mu.Unlock()
 
-	// LRU 驱逐
+	// L1 驱逐
 	if len(sc.entries) >= sc.maxSize {
 		sc.evictLRU()
 	}
@@ -76,6 +156,11 @@ func (sc *SearchCache) Set(query, namespace string, results interface{}) {
 		CreatedAt: time.Now(),
 		Hits:      0,
 	}
+
+	// L2 写入
+	if sc.l2 != nil {
+		sc.l2.Set(key, data, sc.ttl)
+	}
 }
 
 // Stats 返回缓存统计
@@ -83,13 +168,14 @@ func (sc *SearchCache) Stats() map[string]interface{} {
 	sc.mu.RLock()
 	defer sc.mu.RUnlock()
 	return map[string]interface{}{
-		"size":     len(sc.entries),
-		"max_size": sc.maxSize,
-		"ttl":      sc.ttl.String(),
+		"size":      len(sc.entries),
+		"max_size":  sc.maxSize,
+		"ttl":       sc.ttl.String(),
+		"l2_enabled": sc.l2 != nil,
 	}
 }
 
-// Invalidate 使指定 namespace 的缓存失效（本地）
+// Invalidate 使指定 namespace 的缓存失效（L1 + L2）
 func (sc *SearchCache) Invalidate(namespace string) {
 	sc.mu.Lock()
 	defer sc.mu.Unlock()
@@ -98,10 +184,24 @@ func (sc *SearchCache) Invalidate(namespace string) {
 		json.Unmarshal(entry.Results, &parsed)
 		if ns, ok := parsed["namespace"].(string); ok && ns == namespace {
 			delete(sc.entries, key)
+			if sc.l2 != nil {
+				sc.l2.Del(key)
+			}
 		}
 	}
 }
 
+// InvalidateKey 使指定 key 失效（L1 + L2）
+func (sc *SearchCache) InvalidateKey(query, namespace string) {
+	key := cacheKey(query, namespace)
+	sc.mu.Lock()
+	delete(sc.entries, key)
+	sc.mu.Unlock()
+	if sc.l2 != nil {
+		sc.l2.Del(key)
+	}
+}
+
 func (sc *SearchCache) evictLRU() {
 	var oldestKey string
 	var oldestTime time.Time
@@ -120,9 +220,13 @@ func (sc *SearchCache) reaper() {
 	ticker := time.NewTicker(5 * time.Minute)
 	for range ticker.C {
 		sc.mu.Lock()
+		now := time.Now()
 		for key, entry := range sc.entries {
-			if time.Since(entry.CreatedAt) > sc.ttl {
+			if now.Sub(entry.CreatedAt) > sc.ttl {
 				delete(sc.entries, key)
+				if sc.l2 != nil {
+					sc.l2.Del(key)
+				}
 			}
 		}
 		sc.mu.Unlock()
@@ -134,5 +238,9 @@ func cacheKey(query, namespace string) string {
 	return fmt.Sprintf("%x", h[:16])
 }
 
-// 全局搜索缓存实例
-var SearchCacheInstance = NewSearchCache(1000, 1*time.Hour)
+// ─── 全局搜索缓存实例（G9：带 Redis L2） ─────────────────────
+var SearchCacheInstance *SearchCache
+
+func init() {
+	SearchCacheInstance = NewSearchCacheWithRedis(1000, 1*time.Hour)
+}
\ No newline at end of file