For reference I've got this problem on Ubuntu 16.04 with the HWE kernel installed on VM's as well. I'd gone a long time using LXC and KVM, avoiding Hyper-V because of the VSS Read Only issue that took 2 years to fix. Noticed that was marked as fixed and almost straight away on first try of Hyper-V again hit this issue :( Machine was on Dynamic memory but I've tried giving it 4GB of RAM fixed as well. Currently it's only got Docker and Portainer pretty much running on it and normally loads of free RAM. Backups for machines start at 2am and the console I don't have an image of but is showing the same messages people are saying on the 4.4 kernel here. Aug 16 02:03:14 kt-docker-01 kernel: [13629.889988] hv_utils: TimeSync IC version 4.0 Aug 16 02:03:14 kt-docker-01 kernel: [13629.890862] sd 0:0:0:0: [storvsc] Sense Key : Unit Attention [current] Aug 16 02:03:14 kt-docker-01 kernel: [13629.890952] sd 0:0:0:0: [storvsc] Add. Sense: Changed operating definition Aug 16 02:03:14 kt-docker-01 kernel: [13629.891023] sd 0:0:0:0: Warning! Received an indication that the operating parameters on this target have changed. The Linux SCSI layer does not automa Aug 16 02:03:14 kt-docker-01 kernel: [13629.916480] sd 0:0:0:1: [storvsc] Sense Key : Unit Attention [current] Aug 16 02:03:14 kt-docker-01 kernel: [13629.916544] sd 0:0:0:1: [storvsc] Add. Sense: Changed operating definition Aug 16 02:03:14 kt-docker-01 kernel: [13629.916629] sd 0:0:0:1: Warning! Received an indication that the operating parameters on this target have changed. The Linux SCSI layer does not automa Aug 16 02:03:14 kt-docker-01 kernel: [13630.077401] scsi 0:0:1:0: Direct-Access Msft Virtual Disk 1.0 PQ: 0 ANSI: 5 Aug 16 02:03:14 kt-docker-01 kernel: [13630.162300] scsi host0: scsi_prep_async_scan called twice Aug 16 02:03:14 kt-docker-01 kernel: [13630.250478] scsi host0: scsi_prep_async_scan called twice Aug 16 02:03:14 kt-docker-01 kernel: [13630.310199] scsi host0: scsi_prep_async_scan called twice Aug 16 02:03:14 kt-docker-01 kernel: [13630.372832] sd 0:0:1:0: [sdc] Sector size 0 reported, assuming 512. Aug 16 02:03:14 kt-docker-01 kernel: [13630.373303] sd 0:0:1:0: Attached scsi generic sg2 type 0 Aug 16 02:03:14 kt-docker-01 kernel: [13630.373429] sd 0:0:1:0: [sdc] 1 512-byte logical blocks: (512 B/512 B) Aug 16 02:03:14 kt-docker-01 kernel: [13630.373434] sd 0:0:1:0: [sdc] 0-byte physical blocks Aug 16 02:03:14 kt-docker-01 kernel: [13630.373559] sd 0:0:1:0: [sdc] Write Protect is off Aug 16 02:03:14 kt-docker-01 kernel: [13630.373562] sd 0:0:1:0: [sdc] Mode Sense: 00 00 00 00 Aug 16 02:03:14 kt-docker-01 kernel: [13630.373652] sd 0:0:1:0: [sdc] Asking for cache data failed Aug 16 02:03:14 kt-docker-01 kernel: [13630.373733] sd 0:0:1:0: [sdc] Assuming drive cache: write through Aug 16 02:03:14 kt-docker-01 kernel: [13630.374612] sd 0:0:1:0: [sdc] Sector size 0 reported, assuming 512. Aug 16 02:03:14 kt-docker-01 kernel: [13630.375205] sd 0:0:1:0: [sdc] Attached SCSI disk Aug 16 02:17:07 kt-docker-01 kernel: [14462.940527] sd 0:0:0:0: [storvsc] Sense Key : Unit Attention [current] Aug 16 02:17:07 kt-docker-01 kernel: [14462.940579] sd 0:0:0:0: [storvsc] Add. Sense: Changed operating definition Aug 16 02:17:07 kt-docker-01 kernel: [14462.940647] sd 0:0:0:0: Warning! Received an indication that the operating parameters on this target have changed. The Linux SCSI layer does not automa Aug 16 02:26:34 kt-docker-01 kernel: [15029.468566] sd 0:0:0:1: [storvsc] Sense Key : Unit Attention [current] Aug 16 02:26:34 kt-docker-01 kernel: [15029.468636] sd 0:0:0:1: [storvsc] Add. Sense: Changed operating definition Aug 16 02:26:34 kt-docker-01 kernel: [15029.468784] sd 0:0:0:1: Warning! Received an indication that the operating parameters on this target have changed. The Linux SCSI layer does not automa Aug 17 02:03:25 kt-docker-01 kernel: [100040.959106] hv_utils: TimeSync IC version 4.0 Aug 17 02:03:25 kt-docker-01 kernel: [100040.960007] sd 0:0:0:0: [storvsc] Sense Key : Unit Attention [current] Aug 17 02:03:25 kt-docker-01 kernel: [100040.960081] sd 0:0:0:0: [storvsc] Add. Sense: Changed operating definition Aug 17 02:03:25 kt-docker-01 kernel: [100040.960152] sd 0:0:0:0: Warning! Received an indication that the operating parameters on this target have changed. The Linux SCSI layer does not automa Aug 17 02:03:25 kt-docker-01 kernel: [100040.979414] sd 0:0:0:1: [storvsc] Sense Key : Unit Attention [current] Aug 17 02:03:25 kt-docker-01 kernel: [100040.979422] sd 0:0:0:1: [storvsc] Add. Sense: Changed operating definition Aug 17 02:03:25 kt-docker-01 kernel: [100040.979482] sd 0:0:0:1: Warning! Received an indication that the operating parameters on this target have changed. The Linux SCSI layer does not automa Aug 17 02:03:25 kt-docker-01 kernel: [100041.135371] scsi 0:0:1:0: Direct-Access Msft Virtual Disk 1.0 PQ: 0 ANSI: 5 Aug 17 02:03:25 kt-docker-01 kernel: [100041.212473] scsi host0: scsi_prep_async_scan called twice Aug 17 02:03:25 kt-docker-01 kernel: [100041.284612] scsi host0: scsi_prep_async_scan called twice Aug 17 02:03:25 kt-docker-01 kernel: [100041.348567] scsi host0: scsi_prep_async_scan called twice Aug 17 02:17:06 kt-docker-01 kernel: [100861.916359] sd 0:0:0:0: [storvsc] Sense Key : Unit Attention [current] Aug 17 02:17:06 kt-docker-01 kernel: [100861.916411] sd 0:0:0:0: [storvsc] Add. Sense: Changed operating definition Aug 17 02:17:06 kt-docker-01 kernel: [100861.916464] sd 0:0:0:0: Warning! Received an indication that the operating parameters on this target have changed. The Linux SCSI layer does not automa Aug 17 02:27:03 kt-docker-01 kernel: [101459.420705] sd 0:0:0:1: [storvsc] Sense Key : Unit Attention [current] Aug 17 02:27:03 kt-docker-01 kernel: [101459.420752] sd 0:0:0:1: [storvsc] Add. Sense: Changed operating definition Aug 17 02:27:03 kt-docker-01 kernel: [101459.420806] sd 0:0:0:1: Warning! Received an indication that the operating parameters on this target have changed. The Linux SCSI layer does not automa Aug 18 02:05:21 kt-docker-01 kernel: [186556.425137] hv_utils: TimeSync IC version 4.0 Aug 18 02:05:21 kt-docker-01 kernel: [186556.426044] sd 0:0:0:0: [storvsc] Sense Key : Unit Attention [current] Aug 18 02:05:21 kt-docker-01 kernel: [186556.426134] sd 0:0:0:0: [storvsc] Add. Sense: Changed operating definition Aug 18 02:05:21 kt-docker-01 kernel: [186556.426513] sd 0:0:0:0: Warning! Received an indication that the operating parameters on this target have changed. The Linux SCSI layer does not automa Aug 18 02:05:21 kt-docker-01 kernel: [186556.443297] sd 0:0:0:1: [storvsc] Sense Key : Unit Attention [current] Aug 18 02:05:21 kt-docker-01 kernel: [186556.443304] sd 0:0:0:1: [storvsc] Add. Sense: Changed operating definition Aug 18 02:05:21 kt-docker-01 kernel: [186556.443352] sd 0:0:0:1: Warning! Received an indication that the operating parameters on this target have changed. The Linux SCSI layer does not automa Aug 18 02:05:21 kt-docker-01 kernel: [186556.596853] scsi 0:0:1:0: Direct-Access Msft Virtual Disk 1.0 PQ: 0 ANSI: 5 Aug 18 02:05:21 kt-docker-01 kernel: [186556.698256] sd 0:0:1:0: [sdc] Sector size 0 reported, assuming 512. Aug 18 02:05:21 kt-docker-01 kernel: [186556.698515] sd 0:0:1:0: [sdc] 0-byte physical blocks Aug 18 02:05:21 kt-docker-01 kernel: [186556.698651] sd 0:0:1:0: [sdc] Write Protect is off Aug 18 02:05:21 kt-docker-01 kernel: [186556.698657] sd 0:0:1:0: [sdc] Mode Sense: 00 00 00 00 Aug 18 02:05:21 kt-docker-01 kernel: [186556.698761] sd 0:0:1:0: [sdc] Asking for cache data failed Aug 18 02:05:21 kt-docker-01 kernel: [186556.698882] sd 0:0:1:0: [sdc] Assuming drive cache: write through Aug 18 02:05:21 kt-docker-01 kernel: [186556.702495] sd 0:0:1:0: [sdc] Sector size 0 reported, assuming 512. Aug 18 02:05:21 kt-docker-01 kernel: [186556.702985] sd 0:0:1:0: Attached scsi generic sg2 type 0 Aug 18 02:05:21 kt-docker-01 kernel: [186556.705743] scsi host0: scsi_prep_async_scan called twice Aug 18 02:07:31 kt-docker-01 kernel: [186686.428200] INFO: task kworker/1:3:72116 blocked for more than 120 seconds. Aug 18 02:07:31 kt-docker-01 kernel: [186686.428280] Not tainted 4.10.0-32-generic #36~16.04.1-Ubuntu Aug 18 02:07:31 kt-docker-01 kernel: [186686.428345] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. Aug 18 02:07:31 kt-docker-01 kernel: [186686.428452] kworker/1:3 D 0 72116 2 0x00000000 Aug 18 02:07:31 kt-docker-01 kernel: [186686.428467] Workqueue: events storvsc_remove_lun [hv_storvsc] Aug 18 02:07:31 kt-docker-01 kernel: [186686.428470] Call Trace: Aug 18 02:07:31 kt-docker-01 kernel: [186686.428480] __schedule+0x232/0x700 Aug 18 02:07:31 kt-docker-01 kernel: [186686.428484] schedule+0x36/0x80 Aug 18 02:07:31 kt-docker-01 kernel: [186686.428488] schedule_preempt_disabled+0xe/0x10 Aug 18 02:07:31 kt-docker-01 kernel: [186686.428492] __mutex_lock_slowpath+0x193/0x290 Aug 18 02:07:31 kt-docker-01 kernel: [186686.428496] mutex_lock+0x2f/0x40 Aug 18 02:07:31 kt-docker-01 kernel: [186686.428503] scsi_remove_device+0x1e/0x40 Aug 18 02:07:31 kt-docker-01 kernel: [186686.428508] storvsc_remove_lun+0x40/0x60 [hv_storvsc] Aug 18 02:07:31 kt-docker-01 kernel: [186686.428515] process_one_work+0x16b/0x4a0 Aug 18 02:07:31 kt-docker-01 kernel: [186686.428519] worker_thread+0x4b/0x500 Aug 18 02:07:31 kt-docker-01 kernel: [186686.428525] kthread+0x109/0x140 Aug 18 02:07:31 kt-docker-01 kernel: [186686.428529] ? process_one_work+0x4a0/0x4a0 Aug 18 02:07:31 kt-docker-01 kernel: [186686.428534] ? kthread_create_on_node+0x60/0x60 Aug 18 02:07:31 kt-docker-01 kernel: [186686.428539] ret_from_fork+0x2c/0x40 Aug 18 02:07:31 kt-docker-01 kernel: [186686.428544] INFO: task kworker/0:1:73370 blocked for more than 120 seconds. Log goes on and on like this for a bit and then the out of memory errors come not long after. Aug 18 02:27:34 kt-docker-01 kernel: [187890.140323] sd 0:0:0:0: [storvsc] Sense Key : Unit Attention [current] Aug 18 02:27:34 kt-docker-01 kernel: [187890.140379] sd 0:0:0:0: [storvsc] Add. Sense: Changed operating definition Aug 18 02:27:34 kt-docker-01 kernel: [187890.140437] sd 0:0:0:0: Warning! Received an indication that the operating parameters on this target have changed. The Linux SCSI layer does not automa Aug 18 02:27:35 kt-docker-01 kernel: [187890.908266] sd 0:0:0:1: [storvsc] Sense Key : Unit Attention [current] Aug 18 02:27:35 kt-docker-01 kernel: [187890.908309] sd 0:0:0:1: [storvsc] Add. Sense: Changed operating definition Aug 18 02:27:35 kt-docker-01 kernel: [187890.908370] sd 0:0:0:1: Warning! Received an indication that the operating parameters on this target have changed. The Linux SCSI layer does not automa Aug 18 03:13:04 kt-docker-01 kernel: [190619.770857] portainer invoked oom-killer: gfp_mask=0x14200ca(GFP_HIGHUSER_MOVABLE), nodemask=0, order=0, oom_score_adj=0 Aug 18 03:13:04 kt-docker-01 kernel: [190619.770861] portainer cpuset=6571fdeefa680b1a020aa7cdf0d0ce305b8001a950249a4514d72922a304ef0a mems_allowed=0 Aug 18 03:13:04 kt-docker-01 kernel: [190619.770872] CPU: 7 PID: 2820 Comm: portainer Not tainted 4.10.0-32-generic #36~16.04.1-Ubuntu Aug 18 03:13:04 kt-docker-01 kernel: [190619.770874] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v1.0 11/26/2012 Aug 18 03:13:05 kt-docker-01 kernel: [190619.770876] Call Trace: Aug 18 03:13:07 kt-docker-01 kernel: [190619.770889] dump_stack+0x63/0x90 Aug 18 03:13:09 kt-docker-01 kernel: [190619.770897] dump_header+0x7b/0x1fd Aug 18 03:13:10 kt-docker-01 kernel: [190619.770904] ? security_capable_noaudit+0x45/0x60 Aug 18 03:13:10 kt-docker-01 kernel: [190619.770912] oom_kill_process+0x219/0x3e0 Aug 18 03:13:10 kt-docker-01 kernel: [190619.770919] out_of_memory+0x120/0x4b0 Aug 18 03:13:10 kt-docker-01 kernel: [190619.770924] __alloc_pages_slowpath+0x9ea/0xb30 Aug 18 03:13:10 kt-docker-01 kernel: [190619.770930] __alloc_pages_nodemask+0x21a/0x2a0 Aug 18 03:13:10 kt-docker-01 kernel: [190619.770935] alloc_pages_vma+0xa2/0x270 Aug 18 03:13:10 kt-docker-01 kernel: [190619.770940] __read_swap_cache_async+0x121/0x1b0 Aug 18 03:13:10 kt-docker-01 kernel: [190619.770944] read_swap_cache_async+0x26/0x60 Aug 18 03:13:10 kt-docker-01 kernel: [190619.770948] swapin_readahead+0x166/0x200 Aug 18 03:13:10 kt-docker-01 kernel: [190619.770954] ? find_get_entry+0x20/0x110 Aug 18 03:13:10 kt-docker-01 kernel: [190619.770959] ? pagecache_get_page+0x2d/0x2b0 Aug 18 03:13:10 kt-docker-01 kernel: [190619.770966] do_swap_page+0x2ff/0x760 Aug 18 03:13:10 kt-docker-01 kernel: [190619.770972] ? do_wp_page+0x109/0x5d0 Aug 18 03:13:10 kt-docker-01 kernel: [190619.770978] handle_mm_fault+0x85b/0x1270 Aug 18 03:13:10 kt-docker-01 kernel: [190619.770987] __do_page_fault+0x240/0x4e0 Aug 18 03:13:10 kt-docker-01 kernel: [190619.770993] do_page_fault+0x22/0x30 Aug 18 03:13:10 kt-docker-01 kernel: [190619.771000] page_fault+0x28/0x30 Aug 18 03:13:10 kt-docker-01 kernel: [190619.771005] RIP: 0033:0x41bef2 Aug 18 03:13:10 kt-docker-01 kernel: [190619.771008] RSP: 002b:000000c420037eb0 EFLAGS: 00010246 Aug 18 03:13:10 kt-docker-01 kernel: [190619.771012] RAX: 000000c420600000 RBX: 000000c4202c2000 RCX: 0000000000000003 Aug 18 03:13:10 kt-docker-01 kernel: [190619.771014] RDX: 000000c420000000 RSI: 000000c41ffe9ee4 RDI: 0000000000000a80 Aug 18 03:13:10 kt-docker-01 kernel: [190619.771016] RBP: 000000c420037f40 R08: 0000000000000360 R09: 0000000000000000 Aug 18 03:13:10 kt-docker-01 kernel: [190619.771018] R10: 0000000000000080 R11: 000000c4202be6d0 R12: 0000000000000000 Aug 18 03:13:10 kt-docker-01 kernel: [190619.771021] R13: 000000c4200001a0 R14: 000000000043d1a0 R15: 0000000000959b60 Aug 18 03:13:10 kt-docker-01 kernel: [190619.771024] Mem-Info: Aug 18 03:13:10 kt-docker-01 kernel: [190619.771036] active_anon:0 inactive_anon:52 isolated_anon:0 Aug 18 03:13:10 kt-docker-01 kernel: [190619.771036] active_file:117 inactive_file:214 isolated_file:0 Aug 18 03:13:10 kt-docker-01 kernel: [190619.771036] unevictable:915 dirty:0 writeback:0 unstable:0 Aug 18 03:13:10 kt-docker-01 kernel: [190619.771036] slab_reclaimable:18579 slab_unreclaimable:907486 Aug 18 03:13:10 kt-docker-01 kernel: [190619.771036] mapped:784 shmem:6 pagetables:1341 bounce:0 Aug 18 03:13:10 kt-docker-01 kernel: [190619.771036] free:20654 free_pcp:233 free_cma:0 Aug 18 03:13:10 kt-docker-01 kernel: [190619.771047] Node 0 active_anon:0kB inactive_anon:208kB active_file:468kB inactive_file:1052kB unevictable:3660kB isolated(anon):0kB isolated(file):0kB mapped:3136kB dirty:0kB writeback:0kB shmem:$ Aug 18 03:13:10 kt-docker-01 kernel: [190619.771049] Node 0 DMA free:15680kB min:268kB low:332kB high:396kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:12kB unevictable:0kB writepending:0kB present:15996kB managed:15$ Aug 18 03:13:10 kt-docker-01 kernel: [190619.771058] lowmem_reserve[]: 0 3793 3855 3855 3855 Aug 18 03:13:10 kt-docker-01 kernel: [190619.771066] Node 0 DMA32 free:66548kB min:66240kB low:82800kB high:99360kB active_anon:0kB inactive_anon:212kB active_file:432kB inactive_file:928kB unevictable:1768kB writepending:0kB present:40$ Aug 18 03:13:10 kt-docker-01 kernel: [190619.771109] lowmem_reserve[]: 0 0 61 61 61 Aug 18 03:13:10 kt-docker-01 kernel: [190619.771116] Node 0 Normal free:388kB min:1068kB low:1332kB high:1596kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:80kB unevictable:1892kB writepending:0kB present:131072kB ma$ Aug 18 03:13:10 kt-docker-01 kernel: [190619.771126] lowmem_reserve[]: 0 0 0 0 0 Aug 18 03:13:10 kt-docker-01 kernel: [190619.771133] Node 0 DMA: 2*4kB (UM) 2*8kB (UE) 3*16kB (UME) 2*32kB (ME) 3*64kB (UME) 2*128kB (ME) 3*256kB (UME) 2*512kB (ME) 3*1024kB (UME) 1*2048kB (E) 2*4096kB (M) = 15688kB Aug 18 03:13:10 kt-docker-01 kernel: [190619.771187] Node 0 DMA32: 7025*4kB (UMEH) 2514*8kB (UMEH) 742*16kB (UMEH) 197*32kB (UM) 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 66388kB Aug 18 03:13:10 kt-docker-01 kernel: [190619.771210] Node 0 Normal: 79*4kB (UM) 9*8kB (UM) 0*16kB 0*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 388kB Aug 18 03:13:10 kt-docker-01 kernel: [190619.771232] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=1048576kB Aug 18 03:13:10 kt-docker-01 kernel: [190619.771235] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB Aug 18 03:13:10 kt-docker-01 kernel: [190619.771236] 1128 total pagecache pages Aug 18 03:13:10 kt-docker-01 kernel: [190619.771239] 83 pages in swap cache Aug 18 03:13:10 kt-docker-01 kernel: [190619.771242] Swap cache stats: add 248740, delete 248657, find 106207/184703 Aug 18 03:13:10 kt-docker-01 kernel: [190619.771243] Free swap = 3793184kB Aug 18 03:13:10 kt-docker-01 kernel: [190619.771245] Total swap = 4194300kB Aug 18 03:13:10 kt-docker-01 kernel: [190619.771247] 1048326 pages RAM Aug 18 03:13:10 kt-docker-01 kernel: [190619.771248] 0 pages HighMem/MovableOnly Aug 18 03:13:10 kt-docker-01 kernel: [190619.771250] 46356 pages reserved Aug 18 03:13:10 kt-docker-01 kernel: [190619.771251] 0 pages cma reserved Aug 18 03:13:10 kt-docker-01 kernel: [190619.771253] 0 pages hwpoisoned