hv-fcopy-daemon service fails to start if /dev/vmbus/hv_fcopy doesn't exist

[Dan Watkins]

On VMs launched in Azure, /dev/vmbus/hv_fcopy doesn't exist, so hv-fcopy-daemon fails to start. This means that boot is degraded by default:

$ systemctl list-units --failed --no-legend
hv-fcopy-daemon.service loaded failed failed Hyper-V File Copy Protocol Daemon

$ systemctl is-system-running
degraded

which makes detecting other failures much harder to automate.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: linux-cloud-tools-common 4.15.0-15.16
ProcVersionSignature: User Name 4.15.0-1004.4-azure 4.15.15
Uname: Linux 4.15.0-1004-azure x86_64
AlsaDevices: Error: command ['ls', '-l', '/dev/snd/'] failed with exit code 2: ls: cannot access '/dev/snd/': No such file or directory
AplayDevices: Error: [Errno 2] No such file or directory: 'aplay': 'aplay'
ApportVersion: 2.20.9-0ubuntu6
Architecture: amd64
ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord': 'arecord'
CRDA: N/A
Date: Mon Apr 23 16:27:47 2018
Dependencies:

IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig': 'iwconfig'
Lsusb: Error: command ['lsusb'] failed with exit code 1:
MachineType: Microsoft Corporation Virtual Machine
PackageArchitecture: all
PciMultimedia:

ProcFB: 0 hyperv_fb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.15.0-1004-azure root=UUID=fda9466a-9068-447f-8572-6d8d310eabd3 ro console=tty1 console=ttyS0 earlyprintk=ttyS0 rootdelay=300
RelatedPackageVersions:
 linux-restricted-modules-4.15.0-1004-azure N/A
 linux-backports-modules-4.15.0-1004-azure N/A
 linux-firmware N/A
RfKill: Error: [Errno 2] No such file or directory: 'rfkill': 'rfkill'
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 06/02/2017
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 090007
dmi.board.name: Virtual Machine
dmi.board.vendor: Microsoft Corporation
dmi.board.version: 7.0
dmi.chassis.asset.tag: 7783-7084-3265-9085-8269-3286-77
dmi.chassis.type: 3
dmi.chassis.vendor: Microsoft Corporation
dmi.chassis.version: 7.0
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr090007:bd06/02/2017:svnMicrosoftCorporation:pnVirtualMachine:pvr7.0:rvnMicrosoftCorporation:rnVirtualMachine:rvr7.0:cvnMicrosoftCorporation:ct3:cvr7.0:
dmi.product.name: Virtual Machine
dmi.product.uuid: 44FD5ABF-DE16-AD4A-B2E0-6E70167950AF
dmi.product.version: 7.0
dmi.sys.vendor: Microsoft Corporation

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This change was made by a bot.

[Joseph Salisbury (jsalisbury)]

Did this issue start happening after an update/upgrade? Was there a prior kernel version where you were not having this particular problem?

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.16 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.17-rc2

[Eduardo Bonato (ebonato)]

Hi Folks,
I can confirm that bug still on Latest kernel 4.18.

~$ sudo dpkg -l | grep azure
ii linux-azure 4.18.0.1013.12 amd64 Complete Linux kernel for Azure systems.
ii linux-azure-cloud-tools-4.15.0-1036 4.15.0-1036.38 amd64 Linux kernel version specific cloud tools for version 4.15.0-1036
ii linux-azure-cloud-tools-4.18.0-1011 4.18.0-1011.11~18.04.1 amd64 Linux kernel version specific cloud tools for version 4.18.0-1011
ii linux-azure-cloud-tools-4.18.0-1013 4.18.0-1013.13~18.04.1 amd64 Linux kernel version specific cloud tools for version 4.18.0-1013
ii linux-azure-headers-4.15.0-1036 4.15.0-1036.38 all Header files related to Linux kernel version 4.15.0
ii linux-azure-headers-4.18.0-1011 4.18.0-1011.11~18.04.1 all Header files related to Linux kernel version 4.18.0
ii linux-azure-headers-4.18.0-1013 4.18.0-1013.13~18.04.1 all Header files related to Linux kernel version 4.18.0
ii linux-azure-tools-4.15.0-1036 4.15.0-1036.38 amd64 Linux kernel version specific tools for version 4.15.0-1036
ii linux-azure-tools-4.18.0-1011 4.18.0-1011.11~18.04.1 amd64 Linux kernel version specific tools for version 4.18.0-1011
ii linux-azure-tools-4.18.0-1013 4.18.0-1013.13~18.04.1 amd64 Linux kernel version specific tools for version 4.18.0-1013
ii linux-cloud-tools-4.15.0-1036-azure 4.15.0-1036.38 amd64 Linux kernel version specific cloud tools for version 4.15.0-1036
ii linux-cloud-tools-4.18.0-1011-azure 4.18.0-1011.11~18.04.1 amd64 Linux kernel version specific cloud tools for version 4.18.0-1011
ii linux-cloud-tools-4.18.0-1013-azure 4.18.0-1013.13~18.04.1 amd64 Linux kernel version specific cloud tools for version 4.18.0-1013
ii linux-cloud-tools-azure 4.18.0.1013.12 amd64 Linux kernel versioned cloud tools for Azure systems.
ii linux-headers-4.15.0-1036-azure 4.15.0-1036.38 amd64 Linux kernel headers for version 4.15.0 on 64 bit x86 SMP
ii linux-headers-4.18.0-1011-azure 4.18.0-1011.11~18.04.1 amd64 Linux kernel headers for version 4.18.0 on 64 bit x86 SMP
ii linux-headers-4.18.0-1013-azure 4.18.0-1013.13~18.04.1 amd64 Linux kernel headers for version 4.18.0 on 64 bit x86 SMP
ii linux-headers-azure 4.18.0.1013.12 amd64 Linux kernel headers for Azure systems.
rc linux-image-4.15.0-1030-azure 4.15.0-1030.31 amd64 Signed kernel image azure
rc linux-image-4.15.0-1031-azure 4.15.0-1031.32 amd64 Signed kernel image azure
rc linux-image-4.15.0-1032-azure 4.15.0-1032.33 ...

[Eduardo Bonato (ebonato)]

According to this MS Documentation:
https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/reference/integration-services

The hv_fcopy_daemon have a low impact on VM.
The role of this daemon isn't necessary to a Azure VM, as you will not use it to copy files from/to VM (This could be necessary if you are directly on Hyper-V Console )

Looking into debian sources:
https://sources.debian.org/src/linux/5.0.2-1~exp1/debian/hyperv-daemons.hv-fcopy-daemon.service/

You will see that a different condition exist to run this service daemon:
ConditionPathExists=/dev/vmbus/hv_fcopy

So just add this extra condition to ubuntu service description on
/lib/systemd/system/hv-fcopy-daemon.service

Restart your VM and you will see it is no more degraded.

[Bearsh (bearsh)]

@ebonato
in focal, the service fails because of that condition:
$ systemctl status hv-fcopy-daemon.service
● hv-fcopy-daemon.service - Hyper-V File Copy Protocol Daemon
     Loaded: loaded (/lib/systemd/system/hv-fcopy-daemon.service; enabled; vendor preset: enabled)
     Active: inactive (dead)
  Condition: start condition failed at Mon 2020-11-09 10:03:59 UTC; 58s ago
             └─ ConditionPathExists=/dev/vmbus/hv_fcopy was not met

any advise?