zfs_autobackup/test_zfsautobackup.py
2020-07-08 17:07:21 +02:00

678 lines
27 KiB
Python

from basetest import *
import time
import contextlib
import io
class TestZfsAutobackup(unittest2.TestCase):
def setUp(self):
prepare_zpools()
self.longMessage=True
def test_defaults(self):
with self.subTest("no datasets selected"):
#should resume and succeed
with io.StringIO() as buf:
with contextlib.redirect_stderr(buf):
with patch('time.strftime', return_value="20101111000000"):
self.assertTrue(ZfsAutobackup("nonexisting test_target1 --verbose --debug".split(" ")).run())
print(buf.getvalue())
#did we really resume?
self.assertIn("No source filesystems selected", buf.getvalue())
with self.subTest("defaults with full verbose and debug"):
with patch('time.strftime', return_value="20101111000000"):
self.assertFalse(ZfsAutobackup("test test_target1 --verbose --debug".split(" ")).run())
r=shelltest("zfs list -H -o name -r -t all "+TEST_POOLS)
self.assertMultiLineEqual(r,"""
test_source1
test_source1/fs1
test_source1/fs1@test-20101111000000
test_source1/fs1/sub
test_source1/fs1/sub@test-20101111000000
test_source2
test_source2/fs2
test_source2/fs2/sub
test_source2/fs2/sub@test-20101111000000
test_source2/fs3
test_source2/fs3/sub
test_target1
test_target1/test_source1
test_target1/test_source1/fs1
test_target1/test_source1/fs1@test-20101111000000
test_target1/test_source1/fs1/sub
test_target1/test_source1/fs1/sub@test-20101111000000
test_target1/test_source2
test_target1/test_source2/fs2
test_target1/test_source2/fs2/sub
test_target1/test_source2/fs2/sub@test-20101111000000
""")
with self.subTest("bare defaults, allow empty"):
with patch('time.strftime', return_value="20101111000001"):
self.assertFalse(ZfsAutobackup("test test_target1 --allow-empty".split(" ")).run())
r=shelltest("zfs list -H -o name -r -t all "+TEST_POOLS)
self.assertMultiLineEqual(r,"""
test_source1
test_source1/fs1
test_source1/fs1@test-20101111000000
test_source1/fs1@test-20101111000001
test_source1/fs1/sub
test_source1/fs1/sub@test-20101111000000
test_source1/fs1/sub@test-20101111000001
test_source2
test_source2/fs2
test_source2/fs2/sub
test_source2/fs2/sub@test-20101111000000
test_source2/fs2/sub@test-20101111000001
test_source2/fs3
test_source2/fs3/sub
test_target1
test_target1/test_source1
test_target1/test_source1/fs1
test_target1/test_source1/fs1@test-20101111000000
test_target1/test_source1/fs1@test-20101111000001
test_target1/test_source1/fs1/sub
test_target1/test_source1/fs1/sub@test-20101111000000
test_target1/test_source1/fs1/sub@test-20101111000001
test_target1/test_source2
test_target1/test_source2/fs2
test_target1/test_source2/fs2/sub
test_target1/test_source2/fs2/sub@test-20101111000000
test_target1/test_source2/fs2/sub@test-20101111000001
""")
with self.subTest("verify holds"):
r=shelltest("zfs get -r userrefs test_source1 test_source2 test_target1")
self.assertMultiLineEqual(r,"""
NAME PROPERTY VALUE SOURCE
test_source1 userrefs - -
test_source1/fs1 userrefs - -
test_source1/fs1@test-20101111000000 userrefs 0 -
test_source1/fs1@test-20101111000001 userrefs 1 -
test_source1/fs1/sub userrefs - -
test_source1/fs1/sub@test-20101111000000 userrefs 0 -
test_source1/fs1/sub@test-20101111000001 userrefs 1 -
test_source2 userrefs - -
test_source2/fs2 userrefs - -
test_source2/fs2/sub userrefs - -
test_source2/fs2/sub@test-20101111000000 userrefs 0 -
test_source2/fs2/sub@test-20101111000001 userrefs 1 -
test_source2/fs3 userrefs - -
test_source2/fs3/sub userrefs - -
test_target1 userrefs - -
test_target1/test_source1 userrefs - -
test_target1/test_source1/fs1 userrefs - -
test_target1/test_source1/fs1@test-20101111000000 userrefs 0 -
test_target1/test_source1/fs1@test-20101111000001 userrefs 1 -
test_target1/test_source1/fs1/sub userrefs - -
test_target1/test_source1/fs1/sub@test-20101111000000 userrefs 0 -
test_target1/test_source1/fs1/sub@test-20101111000001 userrefs 1 -
test_target1/test_source2 userrefs - -
test_target1/test_source2/fs2 userrefs - -
test_target1/test_source2/fs2/sub userrefs - -
test_target1/test_source2/fs2/sub@test-20101111000000 userrefs 0 -
test_target1/test_source2/fs2/sub@test-20101111000001 userrefs 1 -
""")
def test_ignore_othersnaphots(self):
r=shelltest("zfs snapshot test_source1/fs1@othersimple")
r=shelltest("zfs snapshot test_source1/fs1@otherdate-20001111000000")
with patch('time.strftime', return_value="20101111000000"):
self.assertFalse(ZfsAutobackup("test test_target1 --verbose".split(" ")).run())
r=shelltest("zfs list -H -o name -r -t all "+TEST_POOLS)
self.assertMultiLineEqual(r,"""
test_source1
test_source1/fs1
test_source1/fs1@othersimple
test_source1/fs1@otherdate-20001111000000
test_source1/fs1@test-20101111000000
test_source1/fs1/sub
test_source1/fs1/sub@test-20101111000000
test_source2
test_source2/fs2
test_source2/fs2/sub
test_source2/fs2/sub@test-20101111000000
test_source2/fs3
test_source2/fs3/sub
test_target1
test_target1/test_source1
test_target1/test_source1/fs1
test_target1/test_source1/fs1@test-20101111000000
test_target1/test_source1/fs1/sub
test_target1/test_source1/fs1/sub@test-20101111000000
test_target1/test_source2
test_target1/test_source2/fs2
test_target1/test_source2/fs2/sub
test_target1/test_source2/fs2/sub@test-20101111000000
""")
def test_othersnaphots(self):
r=shelltest("zfs snapshot test_source1/fs1@othersimple")
r=shelltest("zfs snapshot test_source1/fs1@otherdate-20001111000000")
with patch('time.strftime', return_value="20101111000000"):
self.assertFalse(ZfsAutobackup("test test_target1 --verbose --other-snapshots".split(" ")).run())
r=shelltest("zfs list -H -o name -r -t all "+TEST_POOLS)
self.assertMultiLineEqual(r,"""
test_source1
test_source1/fs1
test_source1/fs1@othersimple
test_source1/fs1@otherdate-20001111000000
test_source1/fs1@test-20101111000000
test_source1/fs1/sub
test_source1/fs1/sub@test-20101111000000
test_source2
test_source2/fs2
test_source2/fs2/sub
test_source2/fs2/sub@test-20101111000000
test_source2/fs3
test_source2/fs3/sub
test_target1
test_target1/test_source1
test_target1/test_source1/fs1
test_target1/test_source1/fs1@othersimple
test_target1/test_source1/fs1@otherdate-20001111000000
test_target1/test_source1/fs1@test-20101111000000
test_target1/test_source1/fs1/sub
test_target1/test_source1/fs1/sub@test-20101111000000
test_target1/test_source2
test_target1/test_source2/fs2
test_target1/test_source2/fs2/sub
test_target1/test_source2/fs2/sub@test-20101111000000
""")
def test_nosnapshot(self):
with patch('time.strftime', return_value="20101111000000"):
self.assertFalse(ZfsAutobackup("test test_target1 --verbose --no-snapshot".split(" ")).run())
r=shelltest("zfs list -H -o name -r -t all "+TEST_POOLS)
#(only parents are created )
#TODO: it probably shouldn't create these
self.assertMultiLineEqual(r,"""
test_source1
test_source1/fs1
test_source1/fs1/sub
test_source2
test_source2/fs2
test_source2/fs2/sub
test_source2/fs3
test_source2/fs3/sub
test_target1
test_target1/test_source1
test_target1/test_source2
test_target1/test_source2/fs2
""")
def test_nosend(self):
with patch('time.strftime', return_value="20101111000000"):
self.assertFalse(ZfsAutobackup("test test_target1 --verbose --no-send".split(" ")).run())
r=shelltest("zfs list -H -o name -r -t all "+TEST_POOLS)
#(only parents are created )
#TODO: it probably shouldn't create these
self.assertMultiLineEqual(r,"""
test_source1
test_source1/fs1
test_source1/fs1@test-20101111000000
test_source1/fs1/sub
test_source1/fs1/sub@test-20101111000000
test_source2
test_source2/fs2
test_source2/fs2/sub
test_source2/fs2/sub@test-20101111000000
test_source2/fs3
test_source2/fs3/sub
test_target1
""")
def test_ignorereplicated(self):
r=shelltest("zfs snapshot test_source1/fs1@otherreplication")
with patch('time.strftime', return_value="20101111000000"):
self.assertFalse(ZfsAutobackup("test test_target1 --verbose --ignore-replicated".split(" ")).run())
r=shelltest("zfs list -H -o name -r -t all "+TEST_POOLS)
#(only parents are created )
#TODO: it probably shouldn't create these
self.assertMultiLineEqual(r,"""
test_source1
test_source1/fs1
test_source1/fs1@otherreplication
test_source1/fs1/sub
test_source1/fs1/sub@test-20101111000000
test_source2
test_source2/fs2
test_source2/fs2/sub
test_source2/fs2/sub@test-20101111000000
test_source2/fs3
test_source2/fs3/sub
test_target1
test_target1/test_source1
test_target1/test_source1/fs1
test_target1/test_source1/fs1/sub
test_target1/test_source1/fs1/sub@test-20101111000000
test_target1/test_source2
test_target1/test_source2/fs2
test_target1/test_source2/fs2/sub
test_target1/test_source2/fs2/sub@test-20101111000000
""")
def test_noholds(self):
with patch('time.strftime', return_value="20101111000000"):
self.assertFalse(ZfsAutobackup("test test_target1 --verbose --no-holds".split(" ")).run())
r=shelltest("zfs get -r userrefs test_source1 test_source2 test_target1")
self.assertMultiLineEqual(r,"""
NAME PROPERTY VALUE SOURCE
test_source1 userrefs - -
test_source1/fs1 userrefs - -
test_source1/fs1@test-20101111000000 userrefs 0 -
test_source1/fs1/sub userrefs - -
test_source1/fs1/sub@test-20101111000000 userrefs 0 -
test_source2 userrefs - -
test_source2/fs2 userrefs - -
test_source2/fs2/sub userrefs - -
test_source2/fs2/sub@test-20101111000000 userrefs 0 -
test_source2/fs3 userrefs - -
test_source2/fs3/sub userrefs - -
test_target1 userrefs - -
test_target1/test_source1 userrefs - -
test_target1/test_source1/fs1 userrefs - -
test_target1/test_source1/fs1@test-20101111000000 userrefs 1 -
test_target1/test_source1/fs1/sub userrefs - -
test_target1/test_source1/fs1/sub@test-20101111000000 userrefs 1 -
test_target1/test_source2 userrefs - -
test_target1/test_source2/fs2 userrefs - -
test_target1/test_source2/fs2/sub userrefs - -
test_target1/test_source2/fs2/sub@test-20101111000000 userrefs 1 -
""")
def test_strippath(self):
with patch('time.strftime', return_value="20101111000000"):
self.assertFalse(ZfsAutobackup("test test_target1 --verbose --strip-path=1".split(" ")).run())
r=shelltest("zfs list -H -o name -r -t all "+TEST_POOLS)
self.assertMultiLineEqual(r,"""
test_source1
test_source1/fs1
test_source1/fs1@test-20101111000000
test_source1/fs1/sub
test_source1/fs1/sub@test-20101111000000
test_source2
test_source2/fs2
test_source2/fs2/sub
test_source2/fs2/sub@test-20101111000000
test_source2/fs3
test_source2/fs3/sub
test_target1
test_target1/fs1
test_target1/fs1@test-20101111000000
test_target1/fs1/sub
test_target1/fs1/sub@test-20101111000000
test_target1/fs2
test_target1/fs2/sub
test_target1/fs2/sub@test-20101111000000
""")
def test_clearrefres(self):
#on zfs utils 0.6.x -x isnt supported
r=shelltest("zfs recv -x bla test >/dev/null </dev/zero; echo $?")
if r=="\n2\n":
self.skipTest("This zfs-userspace version doesnt support -x")
r=shelltest("zfs set refreservation=1M test_source1/fs1")
with patch('time.strftime', return_value="20101111000000"):
self.assertFalse(ZfsAutobackup("test test_target1 --verbose --clear-refreservation".split(" ")).run())
r=shelltest("zfs get refreservation -r test_source1 test_source2 test_target1")
self.assertMultiLineEqual(r,"""
NAME PROPERTY VALUE SOURCE
test_source1 refreservation none default
test_source1/fs1 refreservation 1M local
test_source1/fs1@test-20101111000000 refreservation - -
test_source1/fs1/sub refreservation none default
test_source1/fs1/sub@test-20101111000000 refreservation - -
test_source2 refreservation none default
test_source2/fs2 refreservation none default
test_source2/fs2/sub refreservation none default
test_source2/fs2/sub@test-20101111000000 refreservation - -
test_source2/fs3 refreservation none default
test_source2/fs3/sub refreservation none default
test_target1 refreservation none default
test_target1/test_source1 refreservation none default
test_target1/test_source1/fs1 refreservation none default
test_target1/test_source1/fs1@test-20101111000000 refreservation - -
test_target1/test_source1/fs1/sub refreservation none default
test_target1/test_source1/fs1/sub@test-20101111000000 refreservation - -
test_target1/test_source2 refreservation none default
test_target1/test_source2/fs2 refreservation none default
test_target1/test_source2/fs2/sub refreservation none default
test_target1/test_source2/fs2/sub@test-20101111000000 refreservation - -
""")
def test_clearmount(self):
#on zfs utils 0.6.x -o isnt supported
r=shelltest("zfs recv -o bla=1 test >/dev/null </dev/zero; echo $?")
if r=="\n2\n":
self.skipTest("This zfs-userspace version doesnt support -o")
with patch('time.strftime', return_value="20101111000000"):
self.assertFalse(ZfsAutobackup("test test_target1 --verbose --clear-mountpoint".split(" ")).run())
r=shelltest("zfs get canmount -r test_source1 test_source2 test_target1")
self.assertMultiLineEqual(r,"""
NAME PROPERTY VALUE SOURCE
test_source1 canmount on default
test_source1/fs1 canmount on default
test_source1/fs1@test-20101111000000 canmount - -
test_source1/fs1/sub canmount on default
test_source1/fs1/sub@test-20101111000000 canmount - -
test_source2 canmount on default
test_source2/fs2 canmount on default
test_source2/fs2/sub canmount on default
test_source2/fs2/sub@test-20101111000000 canmount - -
test_source2/fs3 canmount on default
test_source2/fs3/sub canmount on default
test_target1 canmount on default
test_target1/test_source1 canmount on default
test_target1/test_source1/fs1 canmount noauto local
test_target1/test_source1/fs1@test-20101111000000 canmount - -
test_target1/test_source1/fs1/sub canmount noauto local
test_target1/test_source1/fs1/sub@test-20101111000000 canmount - -
test_target1/test_source2 canmount on default
test_target1/test_source2/fs2 canmount on default
test_target1/test_source2/fs2/sub canmount noauto local
test_target1/test_source2/fs2/sub@test-20101111000000 canmount - -
""")
def test_rollback(self):
#initial backup
with patch('time.strftime', return_value="20101111000000"):
self.assertFalse(ZfsAutobackup("test test_target1 --verbose".split(" ")).run())
#make change
r=shelltest("zfs mount test_target1/test_source1/fs1")
r=shelltest("touch /test_target1/test_source1/fs1/change.txt")
with patch('time.strftime', return_value="20101111000001"):
#should fail (busy)
self.assertTrue(ZfsAutobackup("test test_target1 --verbose --allow-empty".split(" ")).run())
with patch('time.strftime', return_value="20101111000002"):
#rollback, should succeed
self.assertFalse(ZfsAutobackup("test test_target1 --verbose --allow-empty --rollback".split(" ")).run())
def test_destroyincompat(self):
#initial backup
with patch('time.strftime', return_value="20101111000000"):
self.assertFalse(ZfsAutobackup("test test_target1 --verbose".split(" ")).run())
#add multiple compatible snapshot (written is still 0)
r=shelltest("zfs snapshot test_target1/test_source1/fs1@compatible1")
r=shelltest("zfs snapshot test_target1/test_source1/fs1@compatible2")
with patch('time.strftime', return_value="20101111000001"):
#should be ok, is compatible
self.assertFalse(ZfsAutobackup("test test_target1 --verbose --allow-empty".split(" ")).run())
#add incompatible snapshot by changing and snapshotting
r=shelltest("zfs mount test_target1/test_source1/fs1")
r=shelltest("touch /test_target1/test_source1/fs1/change.txt")
r=shelltest("zfs snapshot test_target1/test_source1/fs1@incompatible1")
with patch('time.strftime', return_value="20101111000002"):
#should fail, now incompatible
self.assertTrue(ZfsAutobackup("test test_target1 --verbose --allow-empty".split(" ")).run())
with patch('time.strftime', return_value="20101111000003"):
#should succeed by destroying incompatibles
self.assertFalse(ZfsAutobackup("test test_target1 --verbose --allow-empty --destroy-incompatible".split(" ")).run())
def test_keepsourcetarget(self):
with patch('time.strftime', return_value="20101111000000"):
self.assertFalse(ZfsAutobackup("test test_target1 --verbose --allow-empty".split(" ")).run())
with patch('time.strftime', return_value="20101111000001"):
self.assertFalse(ZfsAutobackup("test test_target1 --verbose --allow-empty".split(" ")).run())
#should still have all snapshots
r=shelltest("zfs list -H -o name -r -t all "+TEST_POOLS)
self.assertMultiLineEqual(r,"""
test_source1
test_source1/fs1
test_source1/fs1@test-20101111000000
test_source1/fs1@test-20101111000001
test_source1/fs1/sub
test_source1/fs1/sub@test-20101111000000
test_source1/fs1/sub@test-20101111000001
test_source2
test_source2/fs2
test_source2/fs2/sub
test_source2/fs2/sub@test-20101111000000
test_source2/fs2/sub@test-20101111000001
test_source2/fs3
test_source2/fs3/sub
test_target1
test_target1/test_source1
test_target1/test_source1/fs1
test_target1/test_source1/fs1@test-20101111000000
test_target1/test_source1/fs1@test-20101111000001
test_target1/test_source1/fs1/sub
test_target1/test_source1/fs1/sub@test-20101111000000
test_target1/test_source1/fs1/sub@test-20101111000001
test_target1/test_source2
test_target1/test_source2/fs2
test_target1/test_source2/fs2/sub
test_target1/test_source2/fs2/sub@test-20101111000000
test_target1/test_source2/fs2/sub@test-20101111000001
""")
#run again with keep=0
with patch('time.strftime', return_value="20101111000002"):
self.assertFalse(ZfsAutobackup("test test_target1 --verbose --allow-empty --keep-source=0 --keep-target=0".split(" ")).run())
#should only have last snapshots
r=shelltest("zfs list -H -o name -r -t all "+TEST_POOLS)
self.assertMultiLineEqual(r,"""
test_source1
test_source1/fs1
test_source1/fs1@test-20101111000002
test_source1/fs1/sub
test_source1/fs1/sub@test-20101111000002
test_source2
test_source2/fs2
test_source2/fs2/sub
test_source2/fs2/sub@test-20101111000002
test_source2/fs3
test_source2/fs3/sub
test_target1
test_target1/test_source1
test_target1/test_source1/fs1
test_target1/test_source1/fs1@test-20101111000002
test_target1/test_source1/fs1/sub
test_target1/test_source1/fs1/sub@test-20101111000002
test_target1/test_source2
test_target1/test_source2/fs2
test_target1/test_source2/fs2/sub
test_target1/test_source2/fs2/sub@test-20101111000002
""")
def test_ssh(self):
#test all ssh directions
with patch('time.strftime', return_value="20101111000000"):
self.assertFalse(ZfsAutobackup("test test_target1 --verbose --allow-empty --ssh-source localhost".split(" ")).run())
with patch('time.strftime', return_value="20101111000001"):
self.assertFalse(ZfsAutobackup("test test_target1 --verbose --allow-empty --ssh-target localhost".split(" ")).run())
with patch('time.strftime', return_value="20101111000002"):
self.assertFalse(ZfsAutobackup("test test_target1 --verbose --allow-empty --ssh-source localhost --ssh-target localhost".split(" ")).run())
r=shelltest("zfs list -H -o name -r -t all "+TEST_POOLS)
self.assertMultiLineEqual(r,"""
test_source1
test_source1/fs1
test_source1/fs1@test-20101111000000
test_source1/fs1@test-20101111000001
test_source1/fs1@test-20101111000002
test_source1/fs1/sub
test_source1/fs1/sub@test-20101111000000
test_source1/fs1/sub@test-20101111000001
test_source1/fs1/sub@test-20101111000002
test_source2
test_source2/fs2
test_source2/fs2/sub
test_source2/fs2/sub@test-20101111000000
test_source2/fs2/sub@test-20101111000001
test_source2/fs2/sub@test-20101111000002
test_source2/fs3
test_source2/fs3/sub
test_target1
test_target1/test_source1
test_target1/test_source1/fs1
test_target1/test_source1/fs1@test-20101111000000
test_target1/test_source1/fs1@test-20101111000001
test_target1/test_source1/fs1@test-20101111000002
test_target1/test_source1/fs1/sub
test_target1/test_source1/fs1/sub@test-20101111000000
test_target1/test_source1/fs1/sub@test-20101111000001
test_target1/test_source1/fs1/sub@test-20101111000002
test_target1/test_source2
test_target1/test_source2/fs2
test_target1/test_source2/fs2/sub
test_target1/test_source2/fs2/sub@test-20101111000000
test_target1/test_source2/fs2/sub@test-20101111000001
test_target1/test_source2/fs2/sub@test-20101111000002
""")
def test_minchange(self):
#initial
with patch('time.strftime', return_value="20101111000000"):
self.assertFalse(ZfsAutobackup("test test_target1 --verbose --min-change 100000".split(" ")).run())
#make small change, use umount to reflect the changes immediately
r=shelltest("zfs set compress=off test_source1")
r=shelltest("touch /test_source1/fs1/change.txt")
r=shelltest("zfs umount test_source1/fs1; zfs mount test_source1/fs1")
#too small change, takes no snapshots
with patch('time.strftime', return_value="20101111000001"):
self.assertFalse(ZfsAutobackup("test test_target1 --verbose --min-change 100000".split(" ")).run())
#make big change
r=shelltest("dd if=/dev/zero of=/test_source1/fs1/change.txt bs=200000 count=1")
r=shelltest("zfs umount test_source1/fs1; zfs mount test_source1/fs1")
#bigger change, should take snapshot
with patch('time.strftime', return_value="20101111000002"):
self.assertFalse(ZfsAutobackup("test test_target1 --verbose --min-change 100000".split(" ")).run())
r=shelltest("zfs list -H -o name -r -t all "+TEST_POOLS)
self.assertMultiLineEqual(r,"""
test_source1
test_source1/fs1
test_source1/fs1@test-20101111000000
test_source1/fs1@test-20101111000002
test_source1/fs1/sub
test_source1/fs1/sub@test-20101111000000
test_source2
test_source2/fs2
test_source2/fs2/sub
test_source2/fs2/sub@test-20101111000000
test_source2/fs3
test_source2/fs3/sub
test_target1
test_target1/test_source1
test_target1/test_source1/fs1
test_target1/test_source1/fs1@test-20101111000000
test_target1/test_source1/fs1@test-20101111000002
test_target1/test_source1/fs1/sub
test_target1/test_source1/fs1/sub@test-20101111000000
test_target1/test_source2
test_target1/test_source2/fs2
test_target1/test_source2/fs2/sub
test_target1/test_source2/fs2/sub@test-20101111000000
""")
def test_test(self):
with patch('time.strftime', return_value="20101111000000"):
self.assertFalse(ZfsAutobackup("test test_target1 --verbose --test".split(" ")).run())
r=shelltest("zfs list -H -o name -r -t all "+TEST_POOLS)
self.assertMultiLineEqual(r,"""
test_source1
test_source1/fs1
test_source1/fs1/sub
test_source2
test_source2/fs2
test_source2/fs2/sub
test_source2/fs3
test_source2/fs3/sub
test_target1
""")
###########################
# TODO:
def test_raw(self):
self.skipTest("todo: later when travis supports zfs 0.8")
def test_ignoretransfererrors(self):
self.skipTest("todo: create some kind of situation where zfs recv exits with an error but transfer is still ok (happens in practice with acltype)")