diff --git a/tests/qemu-iotests/298 b/tests/qemu-iotests/298
new file mode 100644
index 0000000000..fef10f6a7a
--- /dev/null
+++ b/tests/qemu-iotests/298
@@ -0,0 +1,186 @@
+#!/usr/bin/env python3
+#
+# Test for preallocate filter
+#
+# Copyright (c) 2020 Virtuozzo International GmbH.
+#
+# 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/>.
+#
+
+import os
+import iotests
+
+MiB = 1024 * 1024
+disk = os.path.join(iotests.test_dir, 'disk')
+overlay = os.path.join(iotests.test_dir, 'overlay')
+refdisk = os.path.join(iotests.test_dir, 'refdisk')
+drive_opts = f'node-name=disk,driver={iotests.imgfmt},' \
+    f'file.node-name=filter,file.driver=preallocate,' \
+    f'file.file.node-name=file,file.file.filename={disk}'
+
+
+class TestPreallocateBase(iotests.QMPTestCase):
+    def setUp(self):
+        iotests.qemu_img_create('-f', iotests.imgfmt, disk, str(10 * MiB))
+
+    def tearDown(self):
+        try:
+            self.check_small()
+            check = iotests.qemu_img_check(disk)
+            self.assertFalse('leaks' in check)
+            self.assertFalse('corruptions' in check)
+            self.assertEqual(check['check-errors'], 0)
+        finally:
+            os.remove(disk)
+
+    def check_big(self):
+        self.assertTrue(os.path.getsize(disk) > 100 * MiB)
+
+    def check_small(self):
+        self.assertTrue(os.path.getsize(disk) < 10 * MiB)
+
+
+class TestQemuImg(TestPreallocateBase):
+    def test_qemu_img(self):
+        p = iotests.QemuIoInteractive('--image-opts', drive_opts)
+
+        p.cmd('write 0 1M')
+        p.cmd('flush')
+
+        self.check_big()
+
+        p.close()
+
+
+class TestPreallocateFilter(TestPreallocateBase):
+    def setUp(self):
+        super().setUp()
+        self.vm = iotests.VM().add_drive(path=None, opts=drive_opts)
+        self.vm.launch()
+
+    def tearDown(self):
+        self.vm.shutdown()
+        super().tearDown()
+
+    def test_prealloc(self):
+        self.vm.hmp_qemu_io('drive0', 'write 0 1M')
+        self.check_big()
+
+    def test_external_snapshot(self):
+        self.test_prealloc()
+
+        result = self.vm.qmp('blockdev-snapshot-sync', node_name='disk',
+                             snapshot_file=overlay,
+                             snapshot_node_name='overlay')
+        self.assert_qmp(result, 'return', {})
+
+        # on reopen to  r-o base preallocation should be dropped
+        self.check_small()
+
+        self.vm.hmp_qemu_io('drive0', 'write 1M 1M')
+
+        result = self.vm.qmp('block-commit', device='overlay')
+        self.assert_qmp(result, 'return', {})
+        self.complete_and_wait()
+
+        # commit of new megabyte should trigger preallocation
+        self.check_big()
+
+    def test_reopen_opts(self):
+        result = self.vm.qmp('x-blockdev-reopen', **{
+            'node-name': 'disk',
+            'driver': iotests.imgfmt,
+            'file': {
+                'node-name': 'filter',
+                'driver': 'preallocate',
+                'prealloc-size': 20 * MiB,
+                'prealloc-align': 5 * MiB,
+                'file': {
+                    'node-name': 'file',
+                    'driver': 'file',
+                    'filename': disk
+                }
+            }
+        })
+        self.assert_qmp(result, 'return', {})
+
+        self.vm.hmp_qemu_io('drive0', 'write 0 1M')
+        self.assertTrue(os.path.getsize(disk) == 25 * MiB)
+
+
+class TestTruncate(iotests.QMPTestCase):
+    def setUp(self):
+        iotests.qemu_img_create('-f', iotests.imgfmt, disk, str(10 * MiB))
+        iotests.qemu_img_create('-f', iotests.imgfmt, refdisk, str(10 * MiB))
+
+    def tearDown(self):
+        os.remove(disk)
+        os.remove(refdisk)
+
+    def do_test(self, prealloc_mode, new_size):
+        ret = iotests.qemu_io_silent('--image-opts', '-c', 'write 0 10M', '-c',
+                                     f'truncate -m {prealloc_mode} {new_size}',
+                                     drive_opts)
+        self.assertEqual(ret, 0)
+
+        ret = iotests.qemu_io_silent('-f', iotests.imgfmt, '-c', 'write 0 10M',
+                                     '-c',
+                                     f'truncate -m {prealloc_mode} {new_size}',
+                                     refdisk)
+        self.assertEqual(ret, 0)
+
+        stat = os.stat(disk)
+        refstat = os.stat(refdisk)
+
+        # Probably we'll want preallocate filter to keep align to cluster when
+        # shrink preallocation, so, ignore small differece
+        self.assertLess(abs(stat.st_size - refstat.st_size), 64 * 1024)
+
+        # Preallocate filter may leak some internal clusters (for example, if
+        # guest write far over EOF, skipping some clusters - they will remain
+        # fallocated, preallocate filter don't care about such leaks, it drops
+        # only trailing preallocation.
+        self.assertLess(abs(stat.st_blocks - refstat.st_blocks) * 512,
+                        1024 * 1024)
+
+    def test_real_shrink(self):
+        self.do_test('off', '5M')
+
+    def test_truncate_inside_preallocated_area__falloc(self):
+        self.do_test('falloc', '50M')
+
+    def test_truncate_inside_preallocated_area__metadata(self):
+        self.do_test('metadata', '50M')
+
+    def test_truncate_inside_preallocated_area__full(self):
+        self.do_test('full', '50M')
+
+    def test_truncate_inside_preallocated_area__off(self):
+        self.do_test('off', '50M')
+
+    def test_truncate_over_preallocated_area__falloc(self):
+        self.do_test('falloc', '150M')
+
+    def test_truncate_over_preallocated_area__metadata(self):
+        self.do_test('metadata', '150M')
+
+    def test_truncate_over_preallocated_area__full(self):
+        self.do_test('full', '150M')
+
+    def test_truncate_over_preallocated_area__off(self):
+        self.do_test('off', '150M')
+
+
+if __name__ == '__main__':
+    iotests.main(supported_fmts=['qcow2'])
diff --git a/tests/qemu-iotests/298.out b/tests/qemu-iotests/298.out
new file mode 100644
index 0000000000..fa16b5ccef
--- /dev/null
+++ b/tests/qemu-iotests/298.out
@@ -0,0 +1,5 @@
+.............
+----------------------------------------------------------------------
+Ran 13 tests
+
+OK
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index ff59cfd2d4..15d5f9619b 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -307,6 +307,7 @@
 295 rw
 296 rw
 297 meta
+298 auto quick
 299 auto quick
 300 migration
 301 backing quick
