hvc0 not present in installation via debootstrap (on Xen)

[davidak]

i have installed Ubuntu 16.04 with debootstrap on a XenServer 6.2.

i have also installed xe-guest-utilities, grub-xen and linux-image-virtual.

when booting the VM, i don't see anything in the XenCenter console.

i think this is because there is no hvc0 tty.

as written here, it should start automatically: http://0pointer.de/blog/projects/serial-console.html

> lscpu
Hypervisor vendor: Microsoft
Virtualization type: full

maybe Ubuntu don't recognize Xen?

how can i get this working?

229-4ubuntu4

[Martin Pitt (pitti)]

Do you actually have a /dev/hvc0 device? Device nodes are being created by the kernel, not userspace, thus reassigning.

[davidak (davidak)]

no, that is the problem.

[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 v4.7-rc1 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/v4.7-rc1-yakkety/

[davidak (davidak)]

>Did this issue start happening after an update/upgrade?

No, like i said it is a fresh install using debootstrap.

>Was there a prior kernel version where you were not having this particular problem?

We have hundreds of VMs with Ubuntu 10.04, 12.04 and 14.04 also installed using debootstrap. But they don't use systemd to create the hvc0.

>Would it be possible for you to test the latest upstream kernel?
Yes, tested with 4.7.0-040700rc5-generic.

[davidak (davidak)]

When will this get fixed?

We want to use Ubuntu 16.04 Server in production on Xen, but it is not usable this way.

I tried to boot paravirtualized with packages grub-xen and linux-image-virtual installed, but it didn't boot at all.

Error in XenCenter:

The server failed to handle your request, due to an internal error. The given message may give details useful for debugging the problem.
message: xenopsd internal error: VM = d7a5dbd8-6fff-b29c-8fbe-9f998c4a00a4; domid = 91; Bootloader.Bad_error Traceback (most recent call last):
  File "/usr/bin/pygrub", line 903, in ?
    fs = fsimage.open(file, part_offs[0], bootfsoptions)
IOError: [Errno 95] Operation not supported

Also tried with boot parameter console=hvc0.

Again without paravirtualization, booting works.

$ systemctl status dev-hvc0.device
● dev-hvc0.device
   Loaded: loaded
   Active: inactive (dead)

Maybe that helps. Can i do anything else to help debug this?

[davidak (davidak)]

A workaround is to create a Xen-Template for 16.04 with the default Ubuntu-Installer like described here:

http://tecadmin.net/add-ubuntu-16-04-lts-template-on-xenserver/

(You have to change Xen source code so that it boots!)

But you can't install a minimal installation this way or decide how LVM is structured.

Since there is no activity in this issue for two month now i don't expect any progress in the near future.