diff --git a/tests/qemu-iotests/156 b/tests/qemu-iotests/156
new file mode 100755
index 0000000000..cc95ff1f98
--- /dev/null
+++ b/tests/qemu-iotests/156
@@ -0,0 +1,174 @@
+#!/bin/bash
+#
+# Tests oVirt-like storage migration:
+#  - Create snapshot
+#  - Create target image with (not yet existing) target backing chain
+#    (i.e. just write the name of a soon-to-be-copied-over backing file into it)
+#  - drive-mirror the snapshot to the target with mode=existing and sync=top
+#  - In the meantime, copy the original source files to the destination via
+#    conventional means (i.e. outside of qemu)
+#  - Complete the drive-mirror job
+#  - Delete all source images
+#
+# Copyright (C) 2016 Red Hat, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+# creator
+owner=mreitz@redhat.com
+
+seq="$(basename $0)"
+echo "QA output created by $seq"
+
+here="$PWD"
+status=1	# failure is the default!
+
+_cleanup()
+{
+    rm -f "$TEST_IMG{,.target}{,.backing,.overlay}"
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+. ./common.rc
+. ./common.filter
+. ./common.qemu
+
+_supported_fmt qcow2 qed
+_supported_proto generic
+_supported_os Linux
+
+# Create source disk
+TEST_IMG="$TEST_IMG.backing" _make_test_img 1M
+_make_test_img -b "$TEST_IMG.backing" 1M
+
+$QEMU_IO -c 'write -P 1 0 256k' "$TEST_IMG.backing" | _filter_qemu_io
+$QEMU_IO -c 'write -P 2 64k 192k' "$TEST_IMG" | _filter_qemu_io
+
+_launch_qemu -drive if=none,id=source,file="$TEST_IMG"
+
+_send_qemu_cmd $QEMU_HANDLE \
+    "{ 'execute': 'qmp_capabilities' }" \
+    'return'
+
+# Create snapshot
+TEST_IMG="$TEST_IMG.overlay" _make_test_img -b "$TEST_IMG" 1M
+_send_qemu_cmd $QEMU_HANDLE \
+    "{ 'execute': 'blockdev-snapshot-sync',
+       'arguments': { 'device': 'source',
+                      'snapshot-file': '$TEST_IMG.overlay',
+                      'format': '$IMGFMT',
+                      'mode': 'existing' } }" \
+    'return'
+
+# Write something to the snapshot
+_send_qemu_cmd $QEMU_HANDLE \
+    "{ 'execute': 'human-monitor-command',
+       'arguments': { 'command-line':
+                      'qemu-io source \"write -P 3 128k 128k\"' } }" \
+    'return'
+
+# Create target image
+TEST_IMG="$TEST_IMG.target.overlay" _make_test_img -b "$TEST_IMG.target" 1M
+
+# Mirror snapshot
+_send_qemu_cmd $QEMU_HANDLE \
+    "{ 'execute': 'drive-mirror',
+       'arguments': { 'device': 'source',
+                      'target': '$TEST_IMG.target.overlay',
+                      'mode': 'existing',
+                      'sync': 'top' } }" \
+    'return'
+
+# Wait for convergence
+_send_qemu_cmd $QEMU_HANDLE \
+    '' \
+    'BLOCK_JOB_READY'
+
+# Write some more
+_send_qemu_cmd $QEMU_HANDLE \
+    "{ 'execute': 'human-monitor-command',
+       'arguments': { 'command-line':
+                      'qemu-io source \"write -P 4 192k 64k\"' } }" \
+    'return'
+
+# Copy source backing chain to the target before completing the job
+cp "$TEST_IMG.backing" "$TEST_IMG.target.backing"
+cp "$TEST_IMG" "$TEST_IMG.target"
+$QEMU_IMG rebase -u -b "$TEST_IMG.target.backing" "$TEST_IMG.target"
+
+# Complete block job
+_send_qemu_cmd $QEMU_HANDLE \
+    "{ 'execute': 'block-job-complete',
+       'arguments': { 'device': 'source' } }" \
+    ''
+
+_send_qemu_cmd $QEMU_HANDLE \
+    '' \
+    'BLOCK_JOB_COMPLETED'
+
+# Remove the source images
+rm -f "$TEST_IMG{,.backing,.overlay}"
+
+echo
+
+# Check online disk contents
+_send_qemu_cmd $QEMU_HANDLE \
+    "{ 'execute': 'human-monitor-command',
+       'arguments': { 'command-line':
+                      'qemu-io source \"read -P 1 0k 64k\"' } }" \
+    'return'
+
+_send_qemu_cmd $QEMU_HANDLE \
+    "{ 'execute': 'human-monitor-command',
+       'arguments': { 'command-line':
+                      'qemu-io source \"read -P 2 64k 64k\"' } }" \
+    'return'
+
+_send_qemu_cmd $QEMU_HANDLE \
+    "{ 'execute': 'human-monitor-command',
+       'arguments': { 'command-line':
+                      'qemu-io source \"read -P 3 128k 64k\"' } }" \
+    'return'
+
+_send_qemu_cmd $QEMU_HANDLE \
+    "{ 'execute': 'human-monitor-command',
+       'arguments': { 'command-line':
+                      'qemu-io source \"read -P 4 192k 64k\"' } }" \
+    'return'
+
+echo
+
+_send_qemu_cmd $QEMU_HANDLE \
+    "{ 'execute': 'quit' }" \
+    'return'
+
+wait=1 _cleanup_qemu
+
+echo
+
+# Check offline disk contents
+$QEMU_IO -c 'read -P 1 0k 64k' \
+         -c 'read -P 2 64k 64k' \
+         -c 'read -P 3 128k 64k' \
+         -c 'read -P 4 192k 64k' \
+         "$TEST_IMG.target.overlay" | _filter_qemu_io
+
+echo
+
+# success, all done
+echo '*** done'
+rm -f $seq.full
+status=0
diff --git a/tests/qemu-iotests/156.out b/tests/qemu-iotests/156.out
new file mode 100644
index 0000000000..3af82ae540
--- /dev/null
+++ b/tests/qemu-iotests/156.out
@@ -0,0 +1,48 @@
+QA output created by 156
+Formatting 'TEST_DIR/t.IMGFMT.backing', fmt=IMGFMT size=1048576
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576 backing_file=TEST_DIR/t.IMGFMT.backing
+wrote 262144/262144 bytes at offset 0
+256 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 196608/196608 bytes at offset 65536
+192 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+{"return": {}}
+Formatting 'TEST_DIR/t.IMGFMT.overlay', fmt=IMGFMT size=1048576 backing_file=TEST_DIR/t.IMGFMT
+{"return": {}}
+wrote 131072/131072 bytes at offset 131072
+128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+{"return": ""}
+Formatting 'TEST_DIR/t.IMGFMT.target.overlay', fmt=IMGFMT size=1048576 backing_file=TEST_DIR/t.IMGFMT.target
+{"return": {}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "BLOCK_JOB_READY", "data": {"device": "source", "len": 131072, "offset": 131072, "speed": 0, "type": "mirror"}}
+wrote 65536/65536 bytes at offset 196608
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+{"return": ""}
+{"return": {}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "BLOCK_JOB_COMPLETED", "data": {"device": "source", "len": 196608, "offset": 196608, "speed": 0, "type": "mirror"}}
+
+read 65536/65536 bytes at offset 0
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+{"return": ""}
+read 65536/65536 bytes at offset 65536
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+{"return": ""}
+read 65536/65536 bytes at offset 131072
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+{"return": ""}
+read 65536/65536 bytes at offset 196608
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+{"return": ""}
+
+{"return": {}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "SHUTDOWN"}
+
+read 65536/65536 bytes at offset 0
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 65536/65536 bytes at offset 65536
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 65536/65536 bytes at offset 131072
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 65536/65536 bytes at offset 196608
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+*** done
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index 9f1f2c0d9e..1c6fcb6018 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -155,3 +155,4 @@
 152 rw auto quick
 154 rw auto backing quick
 155 rw auto
+156 rw auto quick