diff --git a/weed/filer/filer_lazy_remote.go b/weed/filer/filer_lazy_remote.go
index 7c642cd6a..0cf4f6eff 100644
--- a/weed/filer/filer_lazy_remote.go
+++ b/weed/filer/filer_lazy_remote.go
@@ -225,3 +225,48 @@ func (f *Filer) maybeDeleteFromRemote(ctx context.Context, entry *Entry) (bool,
 	glog.V(3).InfofCtx(ctx, "maybeDeleteFromRemote: deleted %s from remote", entry.FullPath)
 	return true, nil
 }
+
+// CopyRemoteOnlyEntry copies the remote object of a renamed entry whose
+// content exists only on the remote to the key of newPath, and returns the
+// RemoteEntry of the copy. The rename deletes the old key along with the old
+// entry, and with no local data nothing would write the new key. It returns
+// nil when no copy is needed: the entry has local data, which the remote sync
+// uploads to the new key, it is empty, which the sync writes as an empty
+// object, or it is not under a remote mount. A rename that
+// moves such an entry out of its mount, or onto a remote that cannot copy, is
+// refused, since it would delete the only copy of the content.
+func (f *Filer) CopyRemoteOnlyEntry(ctx context.Context, entry *Entry, oldPath, newPath util.FullPath) (*filer_pb.RemoteEntry, error) {
+	if f.RemoteStorage == nil || entry.IsDirectory() || !entry.IsInRemoteOnly() || len(entry.Content) > 0 {
+		return nil, nil
+	}
+
+	mountDir, remoteLoc := f.RemoteStorage.FindMountDirectory(oldPath)
+	if remoteLoc == nil {
+		return nil, nil
+	}
+	if newMountDir, _ := f.RemoteStorage.FindMountDirectory(newPath); newMountDir != mountDir {
+		return nil, fmt.Errorf("%s exists only on the remote of mount %s and cannot be renamed out of it; cache it first", oldPath, mountDir)
+	}
+
+	remoteConf, found := f.RemoteStorage.GetRemoteStorageConf(remoteLoc.Name)
+	if !found {
+		return nil, fmt.Errorf("resolve remote storage client for %s: not found", oldPath)
+	}
+	client, clientErr := f.buildRemoteStorageClient(ctx, remoteConf)
+	if clientErr != nil {
+		return nil, fmt.Errorf("resolve remote storage client for %s: %w", oldPath, clientErr)
+	}
+	copier, ok := client.(remote_storage.RemoteStorageObjectCopier)
+	if !ok {
+		return nil, fmt.Errorf("%s exists only on the remote and remote storage type %s cannot copy it to the new name; cache it first", oldPath, remoteConf.Type)
+	}
+
+	src := MapFullPathToRemoteStorageLocation(mountDir, remoteLoc, oldPath)
+	dst := MapFullPathToRemoteStorageLocation(mountDir, remoteLoc, newPath)
+	remoteEntry, err := copier.CopyFile(src, dst)
+	if err != nil {
+		return nil, fmt.Errorf("copy remote %s to %s: %w", remote_storage.FormatLocation(src), remote_storage.FormatLocation(dst), err)
+	}
+	glog.V(3).InfofCtx(ctx, "CopyRemoteOnlyEntry: copied %s to %s", remote_storage.FormatLocation(src), remote_storage.FormatLocation(dst))
+	return remoteEntry, nil
+}
diff --git a/weed/remote_storage/remote_storage.go b/weed/remote_storage/remote_storage.go
index f1845e1b0..0cefe362a 100644
--- a/weed/remote_storage/remote_storage.go
+++ b/weed/remote_storage/remote_storage.go
@@ -110,6 +110,14 @@ type RemoteStorageStreamReader interface {
 	ReadFileAsStream(ctx context.Context, loc *remote_pb.RemoteStorageLocation, offset int64, size int64) (reader io.ReadCloser, err error)
 }
 
+// RemoteStorageObjectCopier is an optional interface for remote storage clients
+// that copy an object to another key within the storage, without the content
+// passing through the client. A rename of an entry whose content exists only
+// on the remote needs it.
+type RemoteStorageObjectCopier interface {
+	CopyFile(src *remote_pb.RemoteStorageLocation, dst *remote_pb.RemoteStorageLocation) (remoteEntry *filer_pb.RemoteEntry, err error)
+}
+
 // CacheWaitTimeout is how long a read of an uncached remote-only object waits
 // for the local cache before serving another way: small files wait longer since
 // their cache completes quickly, large files fail fast for better TTFB. A mount
diff --git a/weed/remote_storage/s3/s3_storage_client.go b/weed/remote_storage/s3/s3_storage_client.go
index a57a063cf..bcc9464cc 100644
--- a/weed/remote_storage/s3/s3_storage_client.go
+++ b/weed/remote_storage/s3/s3_storage_client.go
@@ -610,7 +610,7 @@ func (s *s3RemoteStorageClient) UpdateFileMetadata(loc *remote_pb.RemoteStorageL
 			copyInput := &s3.CopyObjectInput{
 				Bucket:                  aws.String(loc.Bucket),
 				Key:                     aws.String(key),
-				CopySource:              aws.String(url.PathEscape(loc.Bucket + "/" + key)),
+				CopySource:              aws.String(s3CopySource(loc.Bucket, key)),
 				MetadataDirective:       aws.String(s3.MetadataDirectiveReplace),
 				Metadata:                headOut.Metadata,
 				ContentType:             headOut.ContentType,
@@ -663,6 +663,160 @@ func (s *s3RemoteStorageClient) UpdateFileMetadata(loc *remote_pb.RemoteStorageL
 	}
 	return
 }
+
+// s3CopyPartSize is the smallest part a multipart copy uses; parts grow so
+// the largest object stays within the 10000-part limit
+const s3CopyPartSize = 512 * 1024 * 1024
+
+// CopyFile copies the object at src to dst on the server side, with a single
+// CopyObject up to the 5 GB limit and a multipart copy above it. The copy
+// keeps the source's metadata.
+func (s *s3RemoteStorageClient) CopyFile(src *remote_pb.RemoteStorageLocation, dst *remote_pb.RemoteStorageLocation) (remoteEntry *filer_pb.RemoteEntry, err error) {
+	srcKey, dstKey := src.Path[1:], dst.Path[1:]
+	headOut, err := s.conn.HeadObject(&s3.HeadObjectInput{
+		Bucket: aws.String(src.Bucket),
+		Key:    aws.String(srcKey),
+	})
+	if err != nil {
+		if reqErr, ok := err.(awserr.RequestFailure); ok && reqErr.StatusCode() == http.StatusNotFound {
+			return nil, remote_storage.ErrRemoteObjectNotFound
+		}
+		return nil, fmt.Errorf("stat s3 %s/%s before copy: %w", src.Bucket, srcKey, err)
+	}
+	copySource := aws.String(s3CopySource(src.Bucket, srcKey))
+	var storageClass *string
+	if s.conf.S3StorageClass != "" {
+		storageClass = aws.String(s.conf.S3StorageClass)
+	}
+
+	if size := aws.Int64Value(headOut.ContentLength); size <= s3CopyObjectSizeLimit {
+		if _, err = s.conn.CopyObject(&s3.CopyObjectInput{
+			Bucket:       aws.String(dst.Bucket),
+			Key:          aws.String(dstKey),
+			CopySource:   copySource,
+			StorageClass: storageClass,
+		}); err != nil {
+			return nil, fmt.Errorf("copy s3 %s/%s to %s/%s: %w", src.Bucket, srcKey, dst.Bucket, dstKey, err)
+		}
+	} else if err = s.multipartCopy(headOut, src, copySource, size, dst.Bucket, dstKey, storageClass); err != nil {
+		return nil, fmt.Errorf("copy s3 %s/%s to %s/%s: %w", src.Bucket, srcKey, dst.Bucket, dstKey, err)
+	}
+
+	return s.readFileRemoteEntry(dst)
+}
+
+// s3CopySource escapes each segment of the copy source and keeps the slashes,
+// which every S3 implementation reads back
+func s3CopySource(bucket, key string) string {
+	segments := strings.Split(bucket+"/"+key, "/")
+	for i, segment := range segments {
+		segments[i] = url.PathEscape(segment)
+	}
+	return strings.Join(segments, "/")
+}
+
+// s3TaggingHeader encodes tags as the query string x-amz-tagging takes, with
+// spaces as %20: a + is read back as a space by some implementations and
+// literally by others
+func s3TaggingHeader(tagSet []*s3.Tag) string {
+	escape := func(s string) string {
+		return strings.ReplaceAll(url.QueryEscape(s), "+", "%20")
+	}
+	pairs := make([]string, 0, len(tagSet))
+	for _, tag := range tagSet {
+		pairs = append(pairs, escape(aws.StringValue(tag.Key))+"="+escape(aws.StringValue(tag.Value)))
+	}
+	return strings.Join(pairs, "&")
+}
+
+// multipartCopy copies an object above the CopyObject limit part by part. A
+// multipart upload does not inherit the source's metadata or tags, so they are
+// carried over like CopyObject would: metadata from the source's HeadObject,
+// tags when the remote supports tagging.
+func (s *s3RemoteStorageClient) multipartCopy(headOut *s3.HeadObjectOutput, src *remote_pb.RemoteStorageLocation, copySource *string, size int64, bucket, key string, storageClass *string) error {
+	createInput := &s3.CreateMultipartUploadInput{
+		Bucket:                  aws.String(bucket),
+		Key:                     aws.String(key),
+		Metadata:                headOut.Metadata,
+		ContentType:             headOut.ContentType,
+		ContentEncoding:         headOut.ContentEncoding,
+		CacheControl:            headOut.CacheControl,
+		ContentDisposition:      headOut.ContentDisposition,
+		ContentLanguage:         headOut.ContentLanguage,
+		WebsiteRedirectLocation: headOut.WebsiteRedirectLocation,
+		StorageClass:            storageClass,
+	}
+	if headOut.Expires != nil {
+		if expires, parseErr := http.ParseTime(*headOut.Expires); parseErr == nil {
+			createInput.Expires = aws.Time(expires)
+		}
+	}
+	if s.conf.S3SupportTagging {
+		tagOut, tagErr := s.conn.GetObjectTagging(&s3.GetObjectTaggingInput{
+			Bucket: aws.String(src.Bucket),
+			Key:    aws.String(src.Path[1:]),
+		})
+		if tagErr != nil {
+			return fmt.Errorf("read tags: %w", tagErr)
+		}
+		if len(tagOut.TagSet) > 0 {
+			createInput.Tagging = aws.String(s3TaggingHeader(tagOut.TagSet))
+		}
+	}
+	createOut, err := s.conn.CreateMultipartUpload(createInput)
+	if err != nil {
+		return err
+	}
+
+	partSize := int64(s3CopyPartSize)
+	for partSize*10000 < size {
+		partSize *= 2
+	}
+	var parts []*s3.CompletedPart
+	for offset, partNumber := int64(0), int64(1); offset < size; offset, partNumber = offset+partSize, partNumber+1 {
+		partOut, partErr := s.conn.UploadPartCopy(&s3.UploadPartCopyInput{
+			Bucket:          aws.String(bucket),
+			Key:             aws.String(key),
+			UploadId:        createOut.UploadId,
+			PartNumber:      aws.Int64(partNumber),
+			CopySource:      copySource,
+			CopySourceRange: aws.String(fmt.Sprintf("bytes=%d-%d", offset, min(offset+partSize, size)-1)),
+		})
+		if partErr == nil && partOut.CopyPartResult == nil {
+			partErr = errors.New("no part result")
+		}
+		if partErr != nil {
+			s.abortMultipartUpload(bucket, key, createOut.UploadId)
+			return fmt.Errorf("copy part %d: %w", partNumber, partErr)
+		}
+		parts = append(parts, &s3.CompletedPart{
+			ETag:       partOut.CopyPartResult.ETag,
+			PartNumber: aws.Int64(partNumber),
+		})
+	}
+
+	if _, err = s.conn.CompleteMultipartUpload(&s3.CompleteMultipartUploadInput{
+		Bucket:          aws.String(bucket),
+		Key:             aws.String(key),
+		UploadId:        createOut.UploadId,
+		MultipartUpload: &s3.CompletedMultipartUpload{Parts: parts},
+	}); err != nil {
+		s.abortMultipartUpload(bucket, key, createOut.UploadId)
+		return err
+	}
+	return nil
+}
+
+func (s *s3RemoteStorageClient) abortMultipartUpload(bucket, key string, uploadId *string) {
+	if _, err := s.conn.AbortMultipartUpload(&s3.AbortMultipartUploadInput{
+		Bucket:   aws.String(bucket),
+		Key:      aws.String(key),
+		UploadId: uploadId,
+	}); err != nil {
+		glog.Warningf("abort multipart copy to s3 %s/%s: %v", bucket, key, err)
+	}
+}
+
 func (s *s3RemoteStorageClient) DeleteFile(loc *remote_pb.RemoteStorageLocation) (err error) {
 	_, err = s.conn.DeleteObject(&s3.DeleteObjectInput{
 		Bucket: aws.String(loc.Bucket),
diff --git a/weed/remote_storage/s3/s3_storage_client_copy_test.go b/weed/remote_storage/s3/s3_storage_client_copy_test.go
new file mode 100644
index 000000000..f30af7bee
--- /dev/null
+++ b/weed/remote_storage/s3/s3_storage_client_copy_test.go
@@ -0,0 +1,160 @@
+package s3
+
+import (
+	"errors"
+	"net/http"
+	"testing"
+
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/aws/awserr"
+	awss3 "github.com/aws/aws-sdk-go/service/s3"
+	"github.com/aws/aws-sdk-go/service/s3/s3iface"
+	"github.com/seaweedfs/seaweedfs/weed/pb/remote_pb"
+	"github.com/seaweedfs/seaweedfs/weed/remote_storage"
+	"github.com/stretchr/testify/require"
+)
+
+// copyObjectMock serves HeadObject for a source of size bytes and records the
+// copy calls.
+type copyObjectMock struct {
+	s3iface.S3API
+	size        int64
+	missing     bool
+	partErr     error
+	copyInputs  []*awss3.CopyObjectInput
+	partInputs  []*awss3.UploadPartCopyInput
+	createInput *awss3.CreateMultipartUploadInput
+	tagInputs   []*awss3.GetObjectTaggingInput
+	completed   *awss3.CompleteMultipartUploadInput
+	aborted     bool
+}
+
+func (m *copyObjectMock) HeadObject(input *awss3.HeadObjectInput) (*awss3.HeadObjectOutput, error) {
+	if m.missing {
+		return nil, awserr.NewRequestFailure(awserr.New("NotFound", "not found", nil), http.StatusNotFound, "")
+	}
+	return &awss3.HeadObjectOutput{
+		ContentLength:           aws.Int64(m.size),
+		ContentType:             aws.String("image/jpeg"),
+		Expires:                 aws.String("Wed, 21 Oct 2026 07:28:00 GMT"),
+		WebsiteRedirectLocation: aws.String("/elsewhere"),
+		ETag:                    aws.String(`"etag-` + aws.StringValue(input.Key) + `"`),
+	}, nil
+}
+
+func (m *copyObjectMock) GetObjectTagging(input *awss3.GetObjectTaggingInput) (*awss3.GetObjectTaggingOutput, error) {
+	m.tagInputs = append(m.tagInputs, input)
+	return &awss3.GetObjectTaggingOutput{TagSet: []*awss3.Tag{
+		{Key: aws.String("album"), Value: aws.String("2026 & co")},
+		{Key: aws.String("a+b"), Value: aws.String("x=y")},
+	}}, nil
+}
+
+func (m *copyObjectMock) CopyObject(input *awss3.CopyObjectInput) (*awss3.CopyObjectOutput, error) {
+	m.copyInputs = append(m.copyInputs, input)
+	return &awss3.CopyObjectOutput{}, nil
+}
+
+func (m *copyObjectMock) CreateMultipartUpload(input *awss3.CreateMultipartUploadInput) (*awss3.CreateMultipartUploadOutput, error) {
+	m.createInput = input
+	return &awss3.CreateMultipartUploadOutput{UploadId: aws.String("upload-1")}, nil
+}
+
+func (m *copyObjectMock) UploadPartCopy(input *awss3.UploadPartCopyInput) (*awss3.UploadPartCopyOutput, error) {
+	m.partInputs = append(m.partInputs, input)
+	if m.partErr != nil && len(m.partInputs) == 2 {
+		return nil, m.partErr
+	}
+	return &awss3.UploadPartCopyOutput{CopyPartResult: &awss3.CopyPartResult{ETag: aws.String(`"part"`)}}, nil
+}
+
+func (m *copyObjectMock) CompleteMultipartUpload(input *awss3.CompleteMultipartUploadInput) (*awss3.CompleteMultipartUploadOutput, error) {
+	m.completed = input
+	return &awss3.CompleteMultipartUploadOutput{}, nil
+}
+
+func (m *copyObjectMock) AbortMultipartUpload(*awss3.AbortMultipartUploadInput) (*awss3.AbortMultipartUploadOutput, error) {
+	m.aborted = true
+	return &awss3.AbortMultipartUploadOutput{}, nil
+}
+
+func newCopyTestClient(mock *copyObjectMock) *s3RemoteStorageClient {
+	return &s3RemoteStorageClient{conf: &remote_pb.RemoteConf{Name: "test"}, conn: mock}
+}
+
+var (
+	copySrc = &remote_pb.RemoteStorageLocation{Name: "test", Bucket: "bucket", Path: "/src/a b.jpg"}
+	copyDst = &remote_pb.RemoteStorageLocation{Name: "test", Bucket: "bucket", Path: "/dst/a b.jpg"}
+)
+
+func TestS3ClientImplementsObjectCopier(t *testing.T) {
+	var _ remote_storage.RemoteStorageObjectCopier = &s3RemoteStorageClient{}
+}
+
+func TestS3CopyFileUsesCopyObjectUpToTheLimit(t *testing.T) {
+	mock := &copyObjectMock{size: s3CopyObjectSizeLimit}
+
+	remoteEntry, err := newCopyTestClient(mock).CopyFile(copySrc, copyDst)
+	require.NoError(t, err)
+
+	require.Len(t, mock.copyInputs, 1)
+	require.Equal(t, "bucket/src/a%20b.jpg", aws.StringValue(mock.copyInputs[0].CopySource))
+	require.Equal(t, "dst/a b.jpg", aws.StringValue(mock.copyInputs[0].Key))
+	require.Nil(t, mock.createInput)
+	// the RemoteEntry describes the destination
+	require.Equal(t, `"etag-dst/a b.jpg"`, remoteEntry.RemoteETag)
+	require.Equal(t, int64(s3CopyObjectSizeLimit), remoteEntry.RemoteSize)
+}
+
+func TestS3CopyFileCopiesLargeObjectsInParts(t *testing.T) {
+	size := int64(s3CopyObjectSizeLimit) + 1
+	mock := &copyObjectMock{size: size}
+
+	_, err := newCopyTestClient(mock).CopyFile(copySrc, copyDst)
+	require.NoError(t, err)
+
+	require.Empty(t, mock.copyInputs)
+	require.NotNil(t, mock.createInput)
+	require.Equal(t, "image/jpeg", aws.StringValue(mock.createInput.ContentType))
+	require.Equal(t, "/elsewhere", aws.StringValue(mock.createInput.WebsiteRedirectLocation))
+	require.Equal(t, int64(1792567680), aws.TimeValue(mock.createInput.Expires).Unix())
+	// tags only where the remote supports tagging
+	require.Empty(t, mock.tagInputs)
+	require.Nil(t, mock.createInput.Tagging)
+	require.Len(t, mock.partInputs, 11)
+	require.Equal(t, "bytes=0-536870911", aws.StringValue(mock.partInputs[0].CopySourceRange))
+	require.Equal(t, "bytes=5368709120-5368709120", aws.StringValue(mock.partInputs[10].CopySourceRange))
+	require.Len(t, mock.completed.MultipartUpload.Parts, 11)
+	require.Equal(t, int64(11), aws.Int64Value(mock.completed.MultipartUpload.Parts[10].PartNumber))
+	require.False(t, mock.aborted)
+}
+
+func TestS3CopyFileCarriesTagsIntoAMultipartCopy(t *testing.T) {
+	mock := &copyObjectMock{size: s3CopyObjectSizeLimit + 1}
+	client := newCopyTestClient(mock)
+	client.conf.S3SupportTagging = true
+
+	_, err := client.CopyFile(copySrc, copyDst)
+	require.NoError(t, err)
+
+	require.Len(t, mock.tagInputs, 1)
+	require.Equal(t, "src/a b.jpg", aws.StringValue(mock.tagInputs[0].Key))
+	require.Equal(t, "album=2026%20%26%20co&a%2Bb=x%3Dy", aws.StringValue(mock.createInput.Tagging))
+}
+
+func TestS3CopyFileAbortsAFailedMultipartCopy(t *testing.T) {
+	mock := &copyObjectMock{size: 2 * s3CopyObjectSizeLimit, partErr: errors.New("part failed")}
+
+	_, err := newCopyTestClient(mock).CopyFile(copySrc, copyDst)
+	require.ErrorContains(t, err, "part failed")
+	require.True(t, mock.aborted)
+	require.Nil(t, mock.completed)
+}
+
+func TestS3CopyFileMissingSource(t *testing.T) {
+	mock := &copyObjectMock{missing: true}
+
+	_, err := newCopyTestClient(mock).CopyFile(copySrc, copyDst)
+	require.ErrorIs(t, err, remote_storage.ErrRemoteObjectNotFound)
+	require.Empty(t, mock.copyInputs)
+}
diff --git a/weed/server/filer_grpc_server_rename.go b/weed/server/filer_grpc_server_rename.go
index 020a59c71..ae097ee41 100644
--- a/weed/server/filer_grpc_server_rename.go
+++ b/weed/server/filer_grpc_server_rename.go
@@ -3,6 +3,7 @@ package weed_server
 import (
 	"context"
 	"fmt"
+	"maps"
 	"path/filepath"
 	"time"
 
@@ -235,8 +236,32 @@ func (fs *FilerServer) moveSelfEntry(ctx context.Context, stream filer_pb.Seawee
 		case !existingTarget.IsDirectory() && entry.IsDirectory():
 			return fmt.Errorf("%s: %w", existingTarget.FullPath, filer_pb.ErrExistingIsFile)
 		}
+	}
+
+	// a remote-only entry is copied on the remote before anything changes:
+	// deleting the old entry deletes the old object
+	copiedRemote, copyErr := fs.filer.CopyRemoteOnlyEntry(ctx, entry, oldPath, newPath)
+	if copyErr != nil {
+		return copyErr
+	}
+	remoteEntry := entry.Remote
+	if copiedRemote != nil {
+		remoteEntry = copiedRemote
+	}
+
+	if existingTarget != nil {
+		targetCtx := filer.WithSuppressedMetadataEvents(ctx)
+		if copiedRemote != nil {
+			// the copy has replaced the target's object; keep it
+			targetCtx = filer.WithKeepRemoteObject(targetCtx)
+			existingTarget.Extended = maps.Clone(existingTarget.Extended)
+			if existingTarget.Extended == nil {
+				existingTarget.Extended = map[string][]byte{}
+			}
+			existingTarget.Extended[filer.ExtKeepRemoteObjectKey] = []byte("true")
+		}
 		if deleteErr := fs.filer.DeleteEntryMetaAndData(
-			filer.WithSuppressedMetadataEvents(ctx),
+			targetCtx,
 			newPath,
 			false,
 			false,
@@ -258,7 +283,7 @@ func (fs *FilerServer) moveSelfEntry(ctx context.Context, stream filer_pb.Seawee
 		Content:         entry.Content,
 		HardLinkCounter: entry.HardLinkCounter,
 		HardLinkId:      entry.HardLinkId,
-		Remote:          entry.Remote,
+		Remote:          remoteEntry,
 		Quota:           entry.Quota,
 	}
 	if skipTargetLookup {
diff --git a/weed/server/filer_grpc_server_rename_remote_test.go b/weed/server/filer_grpc_server_rename_remote_test.go
new file mode 100644
index 000000000..27eab9e0a
--- /dev/null
+++ b/weed/server/filer_grpc_server_rename_remote_test.go
@@ -0,0 +1,282 @@
+package weed_server
+
+import (
+	"context"
+	"errors"
+	"sync"
+	"testing"
+
+	"github.com/seaweedfs/seaweedfs/weed/filer"
+	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
+	"github.com/seaweedfs/seaweedfs/weed/pb/remote_pb"
+	"github.com/seaweedfs/seaweedfs/weed/remote_storage"
+	"github.com/seaweedfs/seaweedfs/weed/util"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"google.golang.org/protobuf/proto"
+)
+
+// renameRemoteClient records the remote calls a rename makes. It cannot copy;
+// copyingRenameRemoteClient adds CopyFile.
+type renameRemoteClient struct {
+	remote_storage.RemoteStorageClient
+	mu      sync.Mutex
+	calls   []string
+	copyErr error
+}
+
+func (c *renameRemoteClient) record(call string) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.calls = append(c.calls, call)
+}
+
+func (c *renameRemoteClient) recorded() []string {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	return append([]string(nil), c.calls...)
+}
+
+func (c *renameRemoteClient) StatFile(*remote_pb.RemoteStorageLocation) (*filer_pb.RemoteEntry, error) {
+	return nil, remote_storage.ErrRemoteObjectNotFound
+}
+
+func (c *renameRemoteClient) ListDirectory(context.Context, *remote_pb.RemoteStorageLocation, remote_storage.VisitFunc) error {
+	return nil
+}
+
+func (c *renameRemoteClient) DeleteFile(loc *remote_pb.RemoteStorageLocation) error {
+	c.record("delete " + loc.Bucket + loc.Path)
+	return nil
+}
+
+func (c *renameRemoteClient) RemoveDirectory(loc *remote_pb.RemoteStorageLocation) error {
+	c.record("rmdir " + loc.Bucket + loc.Path)
+	return nil
+}
+
+type copyingRenameRemoteClient struct {
+	*renameRemoteClient
+}
+
+func (c copyingRenameRemoteClient) CopyFile(src, dst *remote_pb.RemoteStorageLocation) (*filer_pb.RemoteEntry, error) {
+	if c.copyErr != nil {
+		return nil, c.copyErr
+	}
+	c.record("copy " + src.Bucket + src.Path + " " + dst.Bucket + dst.Path)
+	return &filer_pb.RemoteEntry{StorageName: "r1", RemoteSize: 10, RemoteMtime: 1800000000, RemoteETag: `"copy"`}, nil
+}
+
+// newRenameRemoteTestServer mounts /buckets/b, /buckets/c and /data/m on r1,
+// through client.
+func newRenameRemoteTestServer(t *testing.T, client remote_storage.RemoteStorageClient) (*FilerServer, *renameTestStore) {
+	t.Helper()
+	store := newRenameTestStore()
+	f := newRenameTestFiler(t, store)
+	f.BuildGuardedRemoteClient = func(context.Context, *remote_pb.RemoteConf, bool) (remote_storage.RemoteStorageClient, error) {
+		return client, nil
+	}
+	mapping, err := proto.Marshal(&remote_pb.RemoteStorageMapping{Mappings: map[string]*remote_pb.RemoteStorageLocation{
+		"/buckets/b": {Name: "r1", Bucket: "origin", Path: "/"},
+		"/buckets/c": {Name: "r1", Bucket: "other", Path: "/"},
+		"/data/m":    {Name: "r1", Bucket: "origin", Path: "/m"},
+	}})
+	require.NoError(t, err)
+	conf, err := proto.Marshal(&remote_pb.RemoteConf{Name: "r1", Type: "s3"})
+	require.NoError(t, err)
+	for name, content := range map[string][]byte{filer.REMOTE_STORAGE_MOUNT_FILE: mapping, "r1" + filer.REMOTE_STORAGE_CONF_SUFFIX: conf} {
+		entry := newFileEntry(filer.DirectoryEtcRemote+"/"+name, 1)
+		entry.Content = content
+		store.entries[string(entry.FullPath)] = entry
+	}
+	require.NoError(t, f.RemoteStorage.LoadRemoteStorageConfigurationsAndMapping(f))
+	for _, dir := range []string{"/buckets", "/buckets/b", "/buckets/b/src", "/buckets/b/dst", "/buckets/c", "/data", "/data/m"} {
+		store.entries[dir] = newDirectoryEntry(dir, 2)
+	}
+	return &FilerServer{filer: f, option: &FilerOption{}, entryLockTable: util.NewLockTable[util.FullPath]()}, store
+}
+
+func remoteOnlyRenameEntry(path string, inode uint64) *filer.Entry {
+	entry := newFileEntry(path, inode)
+	entry.FileSize = 10
+	entry.Remote = &filer_pb.RemoteEntry{StorageName: "r1", RemoteSize: 10, RemoteMtime: 1700000000, RemoteETag: `"orig"`}
+	return entry
+}
+
+func renameFile(server *FilerServer, oldPath, newPath util.FullPath) error {
+	oldDir, oldName := oldPath.DirAndName()
+	newDir, newName := newPath.DirAndName()
+	_, err := server.AtomicRenameEntry(context.Background(), &filer_pb.AtomicRenameEntryRequest{
+		OldDirectory: oldDir,
+		OldName:      oldName,
+		NewDirectory: newDir,
+		NewName:      newName,
+	})
+	return err
+}
+
+func TestRenameRemoteOnlyEntryCopiesBeforeDeletingTheOldObject(t *testing.T) {
+	client := copyingRenameRemoteClient{&renameRemoteClient{}}
+	server, store := newRenameRemoteTestServer(t, client)
+	store.entries["/buckets/b/src/a.jpg"] = remoteOnlyRenameEntry("/buckets/b/src/a.jpg", 101)
+
+	require.NoError(t, renameFile(server, "/buckets/b/src/a.jpg", "/buckets/b/dst/a.jpg"))
+
+	assert.Equal(t, []string{"copy origin/src/a.jpg origin/dst/a.jpg", "delete origin/src/a.jpg"}, client.recorded())
+	_, err := store.FindEntry(context.Background(), "/buckets/b/src/a.jpg")
+	assert.ErrorIs(t, err, filer_pb.ErrNotFound)
+	dst, err := store.FindEntry(context.Background(), "/buckets/b/dst/a.jpg")
+	require.NoError(t, err)
+	assert.Equal(t, `"copy"`, dst.Remote.RemoteETag)
+	assert.Equal(t, uint64(101), dst.Attr.Inode)
+}
+
+func TestRenameRemoteOnlyEntryOverTargetKeepsTheCopy(t *testing.T) {
+	client := copyingRenameRemoteClient{&renameRemoteClient{}}
+	server, store := newRenameRemoteTestServer(t, client)
+	store.entries["/buckets/b/src/a.jpg"] = remoteOnlyRenameEntry("/buckets/b/src/a.jpg", 101)
+	store.entries["/buckets/b/dst/a.jpg"] = remoteOnlyRenameEntry("/buckets/b/dst/a.jpg", 202)
+	queue := &captureQueue{}
+	swapNotificationQueue(t, queue)
+
+	require.NoError(t, renameFile(server, "/buckets/b/src/a.jpg", "/buckets/b/dst/a.jpg"))
+
+	// the target's delete must not take the copy that replaced its object
+	assert.Equal(t, []string{"copy origin/src/a.jpg origin/dst/a.jpg", "delete origin/src/a.jpg"}, client.recorded())
+	events := queue.snapshot()
+	require.Len(t, events, 2)
+	assert.True(t, filer.IsMetadataOnlyDelete(events[0].notification.OldEntry), "the target's delete event must leave the remote object alone")
+	assert.False(t, filer.IsMetadataOnlyDelete(events[1].notification.OldEntry))
+	dst, err := store.FindEntry(context.Background(), "/buckets/b/dst/a.jpg")
+	require.NoError(t, err)
+	assert.Equal(t, uint64(101), dst.Attr.Inode)
+	assert.Equal(t, `"copy"`, dst.Remote.RemoteETag)
+}
+
+func TestRenameRemoteOnlyEntryCopyFailureChangesNothing(t *testing.T) {
+	client := copyingRenameRemoteClient{&renameRemoteClient{copyErr: errors.New("copy refused")}}
+	server, store := newRenameRemoteTestServer(t, client)
+	store.entries["/buckets/b/src/a.jpg"] = remoteOnlyRenameEntry("/buckets/b/src/a.jpg", 101)
+	store.entries["/buckets/b/dst/a.jpg"] = remoteOnlyRenameEntry("/buckets/b/dst/a.jpg", 202)
+
+	err := renameFile(server, "/buckets/b/src/a.jpg", "/buckets/b/dst/a.jpg")
+	require.ErrorContains(t, err, "copy refused")
+
+	assert.Empty(t, client.recorded())
+	src, err := store.FindEntry(context.Background(), "/buckets/b/src/a.jpg")
+	require.NoError(t, err)
+	assert.Equal(t, `"orig"`, src.Remote.RemoteETag)
+	dst, err := store.FindEntry(context.Background(), "/buckets/b/dst/a.jpg")
+	require.NoError(t, err)
+	assert.Equal(t, uint64(202), dst.Attr.Inode)
+}
+
+func TestRenameRemoteOnlyEntryWithoutCopierIsRefused(t *testing.T) {
+	client := &renameRemoteClient{}
+	server, store := newRenameRemoteTestServer(t, client)
+	store.entries["/buckets/b/src/a.jpg"] = remoteOnlyRenameEntry("/buckets/b/src/a.jpg", 101)
+
+	err := renameFile(server, "/buckets/b/src/a.jpg", "/buckets/b/dst/a.jpg")
+	require.ErrorContains(t, err, "cannot copy")
+
+	assert.Empty(t, client.recorded())
+	_, err = store.FindEntry(context.Background(), "/buckets/b/src/a.jpg")
+	require.NoError(t, err)
+	_, err = store.FindEntry(context.Background(), "/buckets/b/dst/a.jpg")
+	assert.ErrorIs(t, err, filer_pb.ErrNotFound)
+}
+
+func TestRenameRemoteOnlyEntryOutOfItsMountIsRefused(t *testing.T) {
+	for _, paths := range [][2]util.FullPath{
+		{"/buckets/b/src/a.jpg", "/buckets/c/a.jpg"},
+		{"/data/m/a.jpg", "/data/a.jpg"},
+	} {
+		t.Run(string(paths[1]), func(t *testing.T) {
+			client := copyingRenameRemoteClient{&renameRemoteClient{}}
+			server, store := newRenameRemoteTestServer(t, client)
+			store.entries[string(paths[0])] = remoteOnlyRenameEntry(string(paths[0]), 101)
+
+			err := renameFile(server, paths[0], paths[1])
+			require.ErrorContains(t, err, "cannot be renamed out of it")
+
+			assert.Empty(t, client.recorded())
+			_, err = store.FindEntry(context.Background(), paths[0])
+			require.NoError(t, err)
+			_, err = store.FindEntry(context.Background(), paths[1])
+			assert.ErrorIs(t, err, filer_pb.ErrNotFound)
+		})
+	}
+}
+
+func TestRenameEmptyRemoteEntryDoesNotCopy(t *testing.T) {
+	// nothing to lose: no copy, and no refusal even out of the mount or
+	// without a copier; the sync writes an empty object at a new key
+	client := &renameRemoteClient{}
+	server, store := newRenameRemoteTestServer(t, client)
+	for _, path := range []string{"/buckets/b/src/empty", "/data/m/empty"} {
+		entry := remoteOnlyRenameEntry(path, 101)
+		entry.FileSize = 0
+		entry.Remote.RemoteSize = 0
+		store.entries[path] = entry
+	}
+
+	require.NoError(t, renameFile(server, "/buckets/b/src/empty", "/buckets/b/dst/empty"))
+	require.NoError(t, renameFile(server, "/data/m/empty", "/data/empty"))
+
+	assert.Equal(t, []string{"delete origin/src/empty", "delete origin/m/empty"}, client.recorded())
+}
+
+func TestRenameRemoteOnlyEntryFailingAfterTheCopyKeepsTheContent(t *testing.T) {
+	client := copyingRenameRemoteClient{&renameRemoteClient{}}
+	server, store := newRenameRemoteTestServer(t, client)
+	store.entries["/buckets/b/src/a.jpg"] = remoteOnlyRenameEntry("/buckets/b/src/a.jpg", 101)
+	store.commitErr = errors.New("commit failed")
+
+	err := renameFile(server, "/buckets/b/src/a.jpg", "/buckets/b/dst/a.jpg")
+	require.ErrorContains(t, err, "commit failed")
+
+	// remote changes are not rolled back with the store: the old object is
+	// gone, but only after the copy at the new key was written
+	assert.Equal(t, []string{"copy origin/src/a.jpg origin/dst/a.jpg", "delete origin/src/a.jpg"}, client.recorded())
+}
+
+func TestRenameEntryWithLocalDataDoesNotCopy(t *testing.T) {
+	client := copyingRenameRemoteClient{&renameRemoteClient{}}
+	server, store := newRenameRemoteTestServer(t, client)
+	entry := remoteOnlyRenameEntry("/data/m/a.jpg", 101)
+	entry.Chunks = []*filer_pb.FileChunk{{FileId: "1,0123456789", Size: 10}}
+	store.entries["/data/m/a.jpg"] = entry
+
+	// even out of the mount: the old object goes, the content stays local
+	require.NoError(t, renameFile(server, "/data/m/a.jpg", "/data/a.jpg"))
+
+	assert.Equal(t, []string{"delete origin/m/a.jpg"}, client.recorded())
+	dst, err := store.FindEntry(context.Background(), "/data/a.jpg")
+	require.NoError(t, err)
+	assert.Equal(t, `"orig"`, dst.Remote.RemoteETag)
+	assert.Len(t, dst.GetChunks(), 1)
+}
+
+func TestRenameDirectoryCopiesRemoteOnlyChildren(t *testing.T) {
+	client := copyingRenameRemoteClient{&renameRemoteClient{}}
+	server, store := newRenameRemoteTestServer(t, client)
+	store.entries["/buckets/b/src/a.jpg"] = remoteOnlyRenameEntry("/buckets/b/src/a.jpg", 101)
+	local := remoteOnlyRenameEntry("/buckets/b/src/b.jpg", 102)
+	local.Content = []byte("0123456789")
+	store.entries["/buckets/b/src/b.jpg"] = local
+
+	require.NoError(t, renameFile(server, "/buckets/b/src", "/buckets/b/moved"))
+
+	assert.Equal(t, []string{
+		"copy origin/src/a.jpg origin/moved/a.jpg",
+		"delete origin/src/a.jpg",
+		"delete origin/src/b.jpg",
+		"rmdir origin/src",
+	}, client.recorded())
+	moved, err := store.FindEntry(context.Background(), "/buckets/b/moved/a.jpg")
+	require.NoError(t, err)
+	assert.Equal(t, `"copy"`, moved.Remote.RemoteETag)
+	moved, err = store.FindEntry(context.Background(), "/buckets/b/moved/b.jpg")
+	require.NoError(t, err)
+	assert.Equal(t, `"orig"`, moved.Remote.RemoteETag)
+}