diff --git a/CMakeLists.txt b/CMakeLists.txt
index a66212b..25c16ff 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -7,6 +7,11 @@ set(CMAKE_C_EXTENSIONS ON)
 
 include(GNUInstallDirs)
 
+# 默认 prefix=/usr（与 kvspace-c 对齐），前端与后端同装 <prefix>/lib/kvspace。
+if(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
+    set(CMAKE_INSTALL_PREFIX "/usr" CACHE PATH "" FORCE)
+endif()
+
 add_library(kvspace SHARED src/frontend.c)
 
 # 前端 SONAME：libkvspace.so.1
@@ -26,7 +31,7 @@ target_link_libraries(kvspace PRIVATE dl)
 target_compile_definitions(kvspace PRIVATE _GNU_SOURCE)
 
 install(TARGETS kvspace
-    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}/kvspace
 )
 install(DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/include/ DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
 
diff --git a/include/kvspace/kvspace.h b/include/kvspace/kvspace.h
index e43aa0e..6cf1bb2 100644
--- a/include/kvspace/kvspace.h
+++ b/include/kvspace/kvspace.h
@@ -61,7 +61,6 @@ typedef struct {
 /* ── 生命周期 ─────────────────────────────────────────────────── */
 void *kvspaceConnect(const char *dsn);
 void  kvspaceClose(void *h);
-int   kvspaceDisconnect(void *h, char *err, uint32_t err_cap);
 
 /* ── 单点读写 / 目录 ──────────────────────────────────────────── */
 
diff --git a/src/frontend.c b/src/frontend.c
index 57e6f7c..a80c7c5 100644
--- a/src/frontend.c
+++ b/src/frontend.c
@@ -22,7 +22,6 @@
 
 typedef struct {
     void (*free)(void *h);
-    int  (*disconnect)(void *h, char *err, uint32_t err_cap);
     int  (*get)(void *h, const char *key, int resolve, uint8_t **out, uint32_t *out_len);
     void (*readreset)(void *h);
     int  (*getpart)(void *h, const char *key, uint32_t offset, uint32_t len,
@@ -109,7 +108,6 @@ void *kvspaceConnect(const char *dsn) {
     } while (0)
 
     LOAD(free, "kvspaceClose");
-    LOAD(disconnect, "kvspaceDisconnect");
     LOAD(get, "kvspaceGet");
     LOAD(readreset, "kvspaceReadReset");
     LOAD(getpart, "kvspaceGetPart");
@@ -151,11 +149,6 @@ void kvspaceClose(void *h) {
     free(x);
 }
 
-int kvspaceDisconnect(void *h, char *err, uint32_t err_cap) {
-    kvspace_handle *x = H(h);
-    return x->vt->disconnect ? x->vt->disconnect(x->backend, err, err_cap) : 0;
-}
-
 /* ── 单点读写 / 目录（trampoline） ─────────────────────────────────── */
 
 int kvspaceGet(void *h, const char *key, int resolve, uint8_t **out, uint32_t *out_len) {