Headless virt-install results in blank non-responsive prompt

Support
1

Hi everyone,

I think this is just an issue with my lack of KVM experience, so maybe this isn’t even the right forum for this, but here I go anyway. Thanks for taking a look.

I’m trying to set up an almalinux VM running on an almalinux host, with virt-install and running KVM+qemu type setup. The host is headless, so bash only. I also intend for the guest to be headless.

When trying to install using the almalinux installation tree from network, I end up with a whole lot of… nothing. See below, I’m just stuck with a blank prompt no matter how long I wait:

 [lauwnch@HOM-KVM-01 ~]$ virt-install --name KVM-FOREMAN-01 --memory 4096 --vcpus 2 --disk size=60 --os-variant almalinux9 --graphics none --extra-args="console=ttys0" --location https://repo.almalinux.org/almalinux/9/BaseOS/x86_64/os 

Starting install...
Retrieving file vmlinuz...          |  11 MB  00:00:01     
Retrieving file initrd.img...       |  78 MB  00:00:07
Allocating 'KVM-FOREMAN-01.qcow2'   |  60 GB  00:00:02     
Running text console command: virsh --connect qemu:///session console KVM-FOREMAN-01
Connected to domain 'KVM-FOREMAN-01'
Escape character is ^] (Ctrl + ])

I think I set up the text console over serial port correctly, and I’m pretty sure the location I specified has a valid installation tree, since virt-install is pulling kernel and initrd correctly. I’m clearly doing something wrong here, I just don’t know what it is.

Any help or pointers are much appreciated, and if you need any more info I’m happy to provide. Thanks again!

2

if you want to see early boot messages and for example anaconda from a kickstart, then you need a serial device, not a console (e.g. /dev/hvc0). for example:

virt-install \
  --virt-type kvm \
  --name=alma9headless \
  --os-variant=almalinux9 \
  --cpu host-passthrough \
  --vcpus 2 \
  --memory 2048 \
  --disk path=/tmp/alma9headless.qcow2,size=40,format=qcow2,sparse=true,bus=scsi,discard=unmap \
  --controller type=scsi,model=virtio-scsi \
  --network bridge=br0,model=virtio \
  --channel unix,target_type=virtio,name=org.qemu.guest_agent.0 \
  --graphics none \
  --video none \
  --serial pty \
  --metadata title="AlmaLinux 9.0 (headless)" \
  --location /tmp/AlmaLinux-9.0-x86_64-dvd.iso \
  --extra-args='inst.ks=file:alma9_kickstart.cfg console=ttyS0' \
  --initrd-inject=alma9_kickstart.cfg

you don’t really need --serial pty, the important bit is the console=ttyS0 and don’t configure a graphical/virtio console. edit: oh looks like you have a typo and used lowercase ttys0

have a look around my github for some more examples

3

WOW you are absolutely correct, console=ttyS0 works while console=ttys0 does not. Thank you very much! That was my problem for over an hour haha, and that’s what I get for using arguments I don’t fully understand. Time to go figure out why capital S matters :slight_smile: .

4

no probs, glad to help.

it matters as that’s the name of the serial device in the guest /dev/ttyS0 and linux is case-sensitive of course