diff --git a/src/nfs_kv_remove.cpp b/src/nfs_kv_remove.cpp
index f515e2f4..c2a0bf14 100644
--- a/src/nfs_kv_remove.cpp
+++ b/src/nfs_kv_remove.cpp
@@ -22,6 +22,7 @@ struct kv_del_state
     int type = 0;
     bool is_rmdir = false;
     bool rm_data = false;
+    bool allow_cache = true;
     int res = 0, res2 = 0;
     std::function<void(int)> cb;
 };
@@ -48,12 +49,13 @@ static void nfs_kv_continue_delete(kv_del_state *st, int state)
         fprintf(stderr, "BUG: invalid state in nfs_kv_continue_delete()");
         abort();
     }
+resume_0:
     st->self->parent->db->get(kv_direntry_key(st->dir_ino, st->filename), [st](int res, const std::string & value)
     {
         st->res = res;
         st->direntry_text = value;
         nfs_kv_continue_delete(st, 1);
-    });
+    }, st->allow_cache);
     return;
 resume_1:
     if (st->res < 0)
@@ -82,7 +84,7 @@ resume_1:
         st->res = res;
         st->ientry_text = value;
         nfs_kv_continue_delete(st, 2);
-    });
+    }, st->allow_cache);
     return;
 resume_2:
     if (st->res < 0)
@@ -124,8 +126,8 @@ resume_3:
     if (st->res == -EAGAIN)
     {
         // CAS failure, restart from the beginning
-        nfs_kv_continue_delete(st, 0);
-        return;
+        st->allow_cache = false;
+        goto resume_0;
     }
     else if (st->res < 0 && st->res != -ENOENT)
     {
diff --git a/src/nfs_kv_rename.cpp b/src/nfs_kv_rename.cpp
index 2dce1f12..1f0da052 100644
--- a/src/nfs_kv_rename.cpp
+++ b/src/nfs_kv_rename.cpp
@@ -7,28 +7,46 @@
 
 #include "nfs_proxy.h"
 #include "nfs_kv.h"
+#include "cli.h"
 
 struct nfs_kv_rename_state
 {
     nfs_client_t *self = NULL;
     rpc_op_t *rop = NULL;
+    // params:
     uint64_t old_dir_ino = 0, new_dir_ino = 0;
     std::string old_name, new_name;
-    std::string old_direntry_text;
-    std::string ientry_text;
-    json11::Json direntry, ientry;
+    // state:
+    bool allow_cache = true;
+    std::string old_direntry_text, old_ientry_text, new_direntry_text, new_ientry_text;
+    json11::Json old_direntry, old_ientry, new_direntry, new_ientry;
+    std::string new_dir_prefix;
+    void *list_handle = NULL;
+    bool new_exists = false;
+    bool rm_dest_data = false;
     int res = 0, res2 = 0;
     std::function<void(int)> cb;
 };
 
 static void nfs_kv_continue_rename(nfs_kv_rename_state *st, int state)
 {
-    // Simplified algorithm (non-atomic and without ENOTDIR/EISDIR):
-    // 1) Check if the target directory exists
-    // 2) Delete & save (using CAS) the source direntry
-    // 3) Write the target direntry using CAS, fail if it already exists
-    // 4) Restore the source direntry on failure
-    // Atomic version would require something like a journal
+    // Algorithm (non-atomic of course):
+    // 1) Read source direntry
+    // 2) Read destination direntry
+    // 3) If destination exists:
+    // 3.1) Check file/folder compatibility (EISDIR/ENOTDIR)
+    // 3.2) Check if destination is empty if it's a folder
+    // 4) If not:
+    // 4.1) Check that the destination directory is actually a directory
+    // 5) Overwrite destination direntry, restart from beginning if CAS failure
+    // 6) Delete source direntry, restart from beginning if CAS failure
+    // 7) If the moved direntry was a regular file:
+    // 7.1) Read inode
+    // 7.2) Delete inode if its link count <= 1
+    // 7.3) Delete inode data if its link count <= 1 and it's a regular non-shared file
+    // 7.4) Reduce link count by 1 if it's > 1
+    // 8) If the moved direntry is a directory:
+    // 8.1) Change parent_ino reference in its inode
     if (state == 0)      {}
     else if (state == 1) goto resume_1;
     else if (state == 2) goto resume_2;
@@ -36,37 +54,27 @@ static void nfs_kv_continue_rename(nfs_kv_rename_state *st, int state)
     else if (state == 4) goto resume_4;
     else if (state == 5) goto resume_5;
     else if (state == 6) goto resume_6;
+    else if (state == 7) goto resume_7;
+    else if (state == 8) goto resume_8;
+    else if (state == 9) goto resume_9;
+    else if (state == 10) goto resume_10;
+    else if (state == 11) goto resume_11;
+    else if (state == 12) goto resume_12;
     else
     {
         fprintf(stderr, "BUG: invalid state in nfs_kv_continue_rename()");
         abort();
     }
-    kv_read_inode(st->self, st->new_dir_ino, [st](int res, const std::string & value, json11::Json attrs)
+resume_0:
+    // Read the old direntry
+    st->self->parent->db->get(kv_direntry_key(st->old_dir_ino, st->old_name), [=](int res, const std::string & value)
     {
-        st->res = res == 0 ? (attrs["type"].string_value() == "dir" ? 0 : -ENOTDIR) : res;
+        st->res = res;
+        st->old_direntry_text = value;
         nfs_kv_continue_rename(st, 1);
-    });
+    }, st->allow_cache);
     return;
 resume_1:
-    if (st->res < 0)
-    {
-        auto cb = std::move(st->cb);
-        cb(st->res);
-        return;
-    }
-    // Read & delete the old direntry
-    st->self->parent->db->del(kv_direntry_key(st->old_dir_ino, st->old_name), [st](int res)
-    {
-        st->res = res;
-        nfs_kv_continue_rename(st, 2);
-    }, [=](int res, const std::string & old_value)
-    {
-        st->res = res;
-        st->old_direntry_text = old_value;
-        return true;
-    });
-    return;
-resume_2:
     if (st->res < 0)
     {
         auto cb = std::move(st->cb);
@@ -75,47 +83,85 @@ resume_2:
     }
     {
         std::string err;
-        st->direntry = json11::Json::parse(st->old_direntry_text, err);
+        st->old_direntry = json11::Json::parse(st->old_direntry_text, err);
         if (err != "")
         {
             fprintf(stderr, "Invalid JSON in direntry %s = %s: %s\n",
                 kv_direntry_key(st->old_dir_ino, st->old_name).c_str(),
                 st->old_direntry_text.c_str(), err.c_str());
-        }
-    }
-    if (st->direntry["type"].string_value() == "dir" &&
-        st->direntry["ino"].uint64_value() != 0 &&
-        st->new_dir_ino != st->old_dir_ino)
-    {
-        // Read & check inode
-        kv_read_inode(st->self, st->direntry["ino"].uint64_value(), [st](int res, const std::string & value, json11::Json ientry)
-        {
-            st->res = res;
-            st->ientry_text = value;
-            st->ientry = ientry;
-            nfs_kv_continue_rename(st, 3);
-        });
-        return;
-resume_3:
-        if (st->res < 0)
-        {
             auto cb = std::move(st->cb);
-            cb(st->res);
+            cb(-EIO);
             return;
         }
-        // Change parent reference
+    }
+    // Read the new direntry
+    st->self->parent->db->get(kv_direntry_key(st->new_dir_ino, st->new_name), [=](int res, const std::string & value)
+    {
+        st->res = res;
+        st->new_direntry_text = value;
+        nfs_kv_continue_rename(st, 2);
+    }, st->allow_cache);
+    return;
+resume_2:
+    if (st->res < 0 && st->res != -ENOENT)
+    {
+        auto cb = std::move(st->cb);
+        cb(st->res);
+        return;
+    }
+    if (st->res == 0)
+    {
+        std::string err;
+        st->new_direntry = json11::Json::parse(st->new_direntry_text, err);
+        if (err != "")
         {
-            auto ientry_new = st->ientry.object_items();
-            ientry_new["parent_ino"] = st->new_dir_ino;
-            st->self->parent->db->set(kv_inode_key(st->direntry["ino"].uint64_value()), json11::Json(ientry_new).dump(), [st](int res)
+            fprintf(stderr, "Invalid JSON in direntry %s = %s: %s\n",
+                kv_direntry_key(st->new_dir_ino, st->new_name).c_str(),
+                st->new_direntry_text.c_str(), err.c_str());
+            auto cb = std::move(st->cb);
+            cb(-EIO);
+            return;
+        }
+    }
+    st->new_exists = st->res == 0;
+    if (st->new_exists)
+    {
+        // Check file/folder compatibility (EISDIR/ENOTDIR)
+        if ((st->old_direntry["type"] == "dir") != (st->new_direntry["type"] == "dir"))
+        {
+            auto cb = std::move(st->cb);
+            cb((st->new_direntry["type"] == "dir") ? -ENOTDIR : -EISDIR);
+            return;
+        }
+        if (st->new_direntry["type"] == "dir")
+        {
+            // Check that the destination directory is empty
+            st->new_dir_prefix = kv_direntry_key(st->new_direntry["ino"].uint64_value(), "");
+            st->list_handle = st->self->parent->db->list_start(st->new_dir_prefix);
+            st->self->parent->db->list_next(st->list_handle, [st](int res, const std::string & key, const std::string & value)
             {
                 st->res = res;
-                nfs_kv_continue_rename(st, 4);
-            }, [st](int res, const std::string & old_value)
-            {
-                return old_value == st->ientry_text;
+                nfs_kv_continue_rename(st, 3);
             });
+            return;
+resume_3:
+            st->self->parent->db->list_close(st->list_handle);
+            if (st->res != -ENOENT)
+            {
+                auto cb = std::move(st->cb);
+                cb(-ENOTEMPTY);
+                return;
+            }
         }
+    }
+    else
+    {
+        // Check that the new directory is actually a directory
+        kv_read_inode(st->self, st->new_dir_ino, [st](int res, const std::string & value, json11::Json attrs)
+        {
+            st->res = res == 0 ? (attrs["type"].string_value() == "dir" ? 0 : -ENOTDIR) : res;
+            nfs_kv_continue_rename(st, 4);
+        });
         return;
 resume_4:
         if (st->res < 0)
@@ -125,42 +171,182 @@ resume_4:
             return;
         }
     }
+    // Write the new direntry
     st->self->parent->db->set(kv_direntry_key(st->new_dir_ino, st->new_name), st->old_direntry_text, [st](int res)
     {
         st->res = res;
         nfs_kv_continue_rename(st, 5);
     }, [st](int res, const std::string & old_value)
     {
-        return res == -ENOENT;
+        return st->new_exists ? (old_value == st->new_direntry_text) : (res == -ENOENT);
     });
     return;
 resume_5:
+    if (st->res == -EAGAIN)
+    {
+        // CAS failure
+        st->allow_cache = false;
+        goto resume_0;
+    }
     if (st->res < 0)
     {
-        if (st->res == -EAGAIN)
-            st->res = -EEXIST;
-        st->res2 = st->res;
-        st->self->parent->db->set(kv_direntry_key(st->old_dir_ino, st->old_name), st->old_direntry_text, [st](int res)
+        auto cb = std::move(st->cb);
+        cb(st->res);
+        return;
+    }
+    // Delete the old direntry
+    st->self->parent->db->del(kv_direntry_key(st->old_dir_ino, st->old_name), [st](int res)
+    {
+        st->res = res;
+        nfs_kv_continue_rename(st, 6);
+    }, [=](int res, const std::string & old_value)
+    {
+        return res == 0 && old_value == st->old_direntry_text;
+    });
+    return;
+resume_6:
+    if (st->res == -EAGAIN)
+    {
+        // CAS failure
+        st->allow_cache = false;
+        goto resume_0;
+    }
+    if (st->res < 0)
+    {
+        auto cb = std::move(st->cb);
+        cb(st->res);
+        return;
+    }
+    st->allow_cache = true;
+resume_7again:
+    if (st->new_exists && st->new_direntry["type"].string_value() != "dir")
+    {
+        // (Maybe) delete old destination file data
+        kv_read_inode(st->self, st->new_direntry["ino"].uint64_value(), [st](int res, const std::string & value, json11::Json attrs)
         {
             st->res = res;
-            nfs_kv_continue_rename(st, 6);
-        }, [st](int res, const std::string & old_value)
-        {
-            return res == -ENOENT;
-        });
+            st->new_ientry_text = value;
+            st->new_ientry = attrs;
+            nfs_kv_continue_rename(st, 7);
+        }, st->allow_cache);
         return;
-resume_6:
+resume_7:
+        if (st->res == 0)
+        {
+            // (5) Reduce inode refcount by 1 or delete inode
+            if (st->new_ientry["nlink"].uint64_value() > 1)
+            {
+                auto copy = st->new_ientry.object_items();
+                copy["nlink"] = st->new_ientry["nlink"].uint64_value()-1;
+                st->self->parent->db->set(kv_inode_key(st->new_direntry["ino"].uint64_value()), json11::Json(copy).dump(), [st](int res)
+                {
+                    st->res = res;
+                    nfs_kv_continue_rename(st, 8);
+                }, [st](int res, const std::string & old_value)
+                {
+                    return old_value == st->new_ientry_text;
+                });
+            }
+            else
+            {
+                st->rm_dest_data = kv_map_type(st->new_ientry["type"].string_value()) == NF3REG
+                    && !st->new_ientry["shared_ino"].uint64_value();
+                st->self->parent->db->del(kv_inode_key(st->new_direntry["ino"].uint64_value()), [st](int res)
+                {
+                    st->res = res;
+                    nfs_kv_continue_rename(st, 8);
+                }, [st](int res, const std::string & old_value)
+                {
+                    return old_value == st->new_ientry_text;
+                });
+            }
+            return;
+resume_8:
+            if (st->res == -EAGAIN)
+            {
+                // CAS failure - re-read inode
+                st->allow_cache = false;
+                goto resume_7again;
+            }
+            if (st->res < 0)
+            {
+                auto cb = std::move(st->cb);
+                cb(st->res);
+                return;
+            }
+            // Delete inode data if required
+            if (st->rm_dest_data)
+            {
+                st->self->parent->cmd->loop_and_wait(st->self->parent->cmd->start_rm_data(json11::Json::object {
+                    { "inode", INODE_NO_POOL(st->self->parent->fs_base_inode + st->new_direntry["ino"].uint64_value()) },
+                    { "pool", (uint64_t)INODE_POOL(st->self->parent->fs_base_inode + st->new_direntry["ino"].uint64_value()) },
+                }), [st](const cli_result_t & r)
+                {
+                    if (r.err)
+                    {
+                        fprintf(stderr, "Failed to remove inode %jx data: %s (code %d)\n",
+                            st->new_direntry["ino"].uint64_value(), r.text.c_str(), r.err);
+                    }
+                    st->res = r.err;
+                    nfs_kv_continue_rename(st, 9);
+                });
+                return;
+resume_9:
+                if (st->res < 0)
+                {
+                    auto cb = std::move(st->cb);
+                    cb(st->res);
+                    return;
+                }
+            }
+        }
+    }
+    if (st->old_direntry["type"].string_value() == "dir" && st->new_dir_ino != st->old_dir_ino)
+    {
+        // Change parent_ino in old ientry
+        st->allow_cache = true;
+resume_10:
+        kv_read_inode(st->self, st->old_direntry["ino"].uint64_value(), [st](int res, const std::string & value, json11::Json ientry)
+        {
+            st->res = res;
+            st->old_ientry_text = value;
+            st->old_ientry = ientry;
+            nfs_kv_continue_rename(st, 11);
+        }, st->allow_cache);
+        return;
+resume_11:
         if (st->res < 0)
         {
-            if (st->res == -EAGAIN)
-                st->res = -EEXIST;
-            fprintf(stderr, "error restoring %s = %s after failed rename: %s (code %d)\n",
-                kv_direntry_key(st->old_dir_ino, st->old_name).c_str(), st->old_direntry_text.c_str(),
-                strerror(-st->res), st->res);
+            auto cb = std::move(st->cb);
+            cb(st->res);
+            return;
+        }
+        {
+            auto ientry_new = st->old_ientry.object_items();
+            ientry_new["parent_ino"] = st->new_dir_ino;
+            st->self->parent->db->set(kv_inode_key(st->old_direntry["ino"].uint64_value()), json11::Json(ientry_new).dump(), [st](int res)
+            {
+                st->res = res;
+                nfs_kv_continue_rename(st, 12);
+            }, [st](int res, const std::string & old_value)
+            {
+                return old_value == st->old_ientry_text;
+            });
         }
-        auto cb = std::move(st->cb);
-        cb(st->res2);
         return;
+resume_12:
+        if (st->res == -EAGAIN)
+        {
+            // CAS failure - try again
+            st->allow_cache = false;
+            goto resume_10;
+        }
+        if (st->res < 0)
+        {
+            auto cb = std::move(st->cb);
+            cb(st->res);
+            return;
+        }
     }
     auto cb = std::move(st->cb);
     cb(st->res);
diff --git a/src/nfs_mount.cpp b/src/nfs_mount.cpp
index 2965bee7..eae5865d 100644
--- a/src/nfs_mount.cpp
+++ b/src/nfs_mount.cpp
@@ -10,11 +10,18 @@
 
 nfsstat3 vitastor_nfs_map_err(int err)
 {
+    if (err < 0)
+    {
+        err = -err;
+    }
     return (err == EINVAL ? NFS3ERR_INVAL
         : (err == ENOENT ? NFS3ERR_NOENT
         : (err == ENOSPC ? NFS3ERR_NOSPC
         : (err == EEXIST ? NFS3ERR_EXIST
-        : (err == EIO ? NFS3ERR_IO : (err ? NFS3ERR_IO : NFS3_OK))))));
+        : (err == EISDIR ? NFS3ERR_ISDIR
+        : (err == ENOTDIR ? NFS3ERR_NOTDIR
+        : (err == ENOTEMPTY ? NFS3ERR_NOTEMPTY
+        : (err == EIO ? NFS3ERR_IO : (err ? NFS3ERR_IO : NFS3_OK)))))))));
 }
 
 int nfs3_null_proc(void *opaque, rpc_op_t *rop)
diff --git a/tests/test_nfs.sh b/tests/test_nfs.sh
index 962876d5..8864b68f 100755
--- a/tests/test_nfs.sh
+++ b/tests/test_nfs.sh
@@ -154,4 +154,14 @@ sudo mount localhost:/ ./testdata/nfs -o port=2050,mountport=2050,nfsvers=3,soft
 if ls ./testdata/nfs | grep smallfile; then false; fi
 format_green "rm small ok"
 
+# rename over existing
+echo ZXCVBN > ./testdata/nfs/over1
+mv ./testdata/nfs/over1 ./testdata/nfs/linked2
+sudo umount ./testdata/nfs/
+sudo mount localhost:/ ./testdata/nfs -o port=2050,mountport=2050,nfsvers=3,soft,nolock,tcp
+if ls ./testdata/nfs | grep over1; then false; fi
+[[ "`cat ./testdata/nfs/linked2`" = "ZXCVBN" ]]
+[[ "`cat ./testdata/nfs/linked1`" = "BABABA" ]]
+format_green "rename over existing file ok"
+
 format_green OK