Detailed backup logs:
vzdump 103 --mode snapshot --storage local --mailto
meine@email --compress lzo --mailnotification always --quiet 1 --node pve1
103: 2019-01-20 04:00:01 INFO: Starting Backup of VM 103 (qemu)
103: 2019-01-20 04:00:01 INFO: status = running
103: 2019-01-20 04:00:02 INFO: update VM 103: -lock backup
103: 2019-01-20 04:00:02 INFO: VM Name: meineVM
103: 2019-01-20 04:00:02 INFO: include disk 'scsi0' 'local-zfs:vm-103-disk-0' 40G
103: 2019-01-20 04:00:02 INFO: include disk 'scsi1' 'local-zfs:vm-103-disk-1' 300G
103: 2019-01-20 04:00:02 INFO: backup mode: snapshot
103: 2019-01-20 04:00:02 INFO: ionice priority: 7
103: 2019-01-20 04:00:02 INFO: snapshots found (not included into backup)
103: 2019-01-20 04:00:02 INFO: creating archive '/var/lib/vz/dump/vzdump-qemu-103-2019_01_20-04_00_01.vma.lzo'
103: 2019-01-20 04:00:02 INFO: started backup task '5da88c50-df30-4c2f-acfb-42e021f4d128'
103: 2019-01-20 04:00:05 INFO: status: 0% (104071168/365072220160), sparse 0% (60252160), duration 3, read/write 34/14 MB/s
103: 2019-01-20 04:01:29 INFO: status: 1% (3750100992/365072220160), sparse 0% (259674112), duration 87, read/write 43/41 MB/s
103: 2019-01-20 04:02:33 INFO: status: 2% (7310344192/365072220160), sparse 0% (527671296), duration 151, read/write 55/51 MB/s
103: 2019-01-20 04:03:59 INFO: status: 3% (11015553024/365072220160), sparse 0% (773652480), duration 237, read/write 43/40 MB/s
103: 2019-01-20 04:05:02 INFO: status: 4% (14615183360/365072220160), sparse 0% (909864960), duration 300, read/write 57/54 MB/s
103: 2019-01-20 04:06:06 INFO: status: 5% (18261278720/365072220160), sparse 0% (1172541440), duration 364, read/write 56/52 MB/s
103: 2019-01-20 04:06:45 INFO: status: 6% (23008509952/365072220160), sparse 1% (4264853504), duration 403, read/write 121/42 MB/s
103: 2019-01-20 04:06:49 INFO: status: 7% (25816989696/365072220160), sparse 1% (6912327680), duration 407, read/write 702/40 MB/s
103: 2019-01-20 04:07:04 INFO: status: 8% (29404692480/365072220160), sparse 2% (9776066560), duration 422, read/write 239/48 MB/s
103: 2019-01-20 04:07:09 INFO: status: 9% (33526251520/365072220160), sparse 3% (13699461120), duration 427, read/write 824/39 MB/s
103: 2019-01-20 04:07:48 INFO: status: 10% (36509712384/365072220160), sparse 4% (14695964672), duration 466, read/write 76/50 MB/s
103: 2019-01-20 04:09:05 INFO: status: 11% (40200306688/365072220160), sparse 4% (14933200896), duration 543, read/write 47/44 MB/s
103: 2019-01-20 04:10:24 INFO: status: 12% (43879104512/365072220160), sparse 4% (15185326080), duration 622, read/write 46/43 MB/s
103: 2019-01-20 04:11:46 INFO: status: 13% (47466545152/365072220160), sparse 4% (15321600000), duration 704, read/write 43/42 MB/s
103: 2019-01-20 04:12:55 INFO: status: 14% (51161464832/365072220160), sparse 4% (15758163968), duration 773, read/write 53/47 MB/s
103: 2019-01-20 04:14:00 INFO: status: 15% (54768697344/365072220160), sparse 4% (16191148032), duration 838, read/write 55/48 MB/s
103: 2019-01-20 04:15:18 INFO: status: 16% (58442645504/365072220160), sparse 4% (16630013952), duration 916, read/write 47/41 MB/s
103: 2019-01-20 04:16:28 INFO: status: 17% (62086840320/365072220160), sparse 4% (17101987840), duration 986, read/write 52/45 MB/s
103: 2019-01-20 04:17:41 INFO: status: 18% (65776254976/365072220160), sparse 4% (17572114432), duration 1059, read/write 50/44 MB/s
103: 2019-01-20 04:18:53 INFO: status: 19% (69391876096/365072220160), sparse 4% (17983782912), duration 1131, read/write 50/44 MB/s
103: 2019-01-20 04:20:05 INFO: status: 20% (73038757888/365072220160), sparse 5% (18428964864), duration 1203, read/write 50/44 MB/s
103: 2019-01-20 04:21:09 INFO: status: 21% (76687671296/365072220160), sparse 5% (18865745920), duration 1267, read/write 57/50 MB/s
103: 2019-01-20 04:22:38 INFO: status: 22% (80320790528/365072220160), sparse 5% (19153211392), duration 1356, read/write 40/37 MB/s
103: 2019-01-20 04:24:02 INFO: status: 23% (83983859712/365072220160), sparse 5% (19365507072), duration 1440, read/write 43/41 MB/s
103: 2019-01-20 04:25:18 INFO: status: 24% (87626481664/365072220160), sparse 5% (19589611520), duration 1516, read/write 47/44 MB/s
103: 2019-01-20 04:26:31 INFO: status: 25% (91310981120/365072220160), sparse 5% (19868286976), duration 1589, read/write 50/46 MB/s
103: 2019-01-20 04:27:29 INFO: status: 26% (94969200640/365072220160), sparse 5% (20304920576), duration 1647, read/write 63/55 MB/s
103: 2019-01-20 04:28:26 INFO: status: 27% (98587181056/365072220160), sparse 5% (20774412288), duration 1704, read/write 63/55 MB/s
103: 2019-01-20 04:29:25 INFO: status: 28% (102245466112/365072220160), sparse 5% (21195083776), duration 1763, read/write 62/54 MB/s
103: 2019-01-20 04:30:46 INFO: status: 29% (105902112768/365072220160), sparse 5% (21563695104), duration 1844, read/write 45/40 MB/s
103: 2019-01-20 04:31:58 INFO: status: 30% (109532348416/365072220160), sparse 5% (21804822528), duration 1916, read/write 50/47 MB/s
103: 2019-01-20 04:33:02 INFO: status: 31% (113188864000/365072220160), sparse 6% (22074613760), duration 1980, read/write 57/52 MB/s
103: 2019-01-20 04:34:11 INFO: status: 32% (116846100480/365072220160), sparse 6% (22335692800), duration 2049, read/write 53/49 MB/s
103: 2019-01-20 04:35:20 INFO: status: 33% (120487608320/365072220160), sparse 6% (22564507648), duration 2118, read/write 52/49 MB/s
103: 2019-01-20 04:36:31 INFO: status: 34% (124143927296/365072220160), sparse 6% (22819328000), duration 2189, read/write 51/47 MB/s
103: 2019-01-20 04:37:35 INFO: status: 35% (127807717376/365072220160), sparse 6% (23071670272), duration 2253, read/write 57/53 MB/s
103: 2019-01-20 04:38:12 INFO: status: 35% (130172387328/365072220160), sparse 6% (23206199296), duration 2290, read/write 63/60 MB/s
103: 2019-01-20 04:38:12 ERROR: job failed with err -5 - Input/output error
103: 2019-01-20 04:38:12 INFO: aborting backup job
103: 2019-01-20 04:38:17 ERROR: Backup of VM 103 failed - job failed with err -5 - Input/output error