Ubuntu 18.04 VM installs but boot fails

[wgshef]

I'm new to ProxMox and Linux. I'm setting up a home lab, consisting of VMs and containers for various versions of SQL Server.
I've created an Ubuntu 18.04 (Desktop) VM. It installed successfully, but it fails when booting up.
Results of qm status on the VM:

root@pve:~# qm config 305
boot: order=sata0;ide2;net0
cores: 1
cpu: x86-64-v2-AES
ide2: none,media=cdrom
memory: 2048
meta: creation-qemu=9.0.2,ctime=1747760544
name: SQL2017
net0: virtio=BC:24:11:9C:8E:CB,bridge=vmbr0,firewall=1
numa: 0
ostype: l26
sata0: local-lvm:vm-305-disk-0,size=10G
scsihw: virtio-scsi-single
smbios1: uuid=f35a2141-75fd-4479-87d8-728dc27bc66c
sockets: 1
tags: home-lab;sql
vmgenid: 3bfef9a0-835a-4382-bbf8-4e78f6e1772a

I have tried changing the drive type between SATA and VirtIO SCSI:

root@pve:~# qm config 305
boot: order=virtio0;ide2;net0
cores: 1
cpu: x86-64-v2-AES
ide2: none,media=cdrom
memory: 2048
meta: creation-qemu=9.0.2,ctime=1747760544
name: SQL2017
net0: virtio=BC:24:11:9C:8E:CB,bridge=vmbr0,firewall=1
numa: 0
ostype: l26
scsihw: virtio-scsi-single
smbios1: uuid=f35a2141-75fd-4479-87d8-728dc27bc66c
sockets: 1
tags: home-lab;sql
virtio0: local-lvm:vm-305-disk-0,iothread=1,size=10G
vmgenid: 3bfef9a0-835a-4382-bbf8-4e78f6e1772a

I've also tried changing the CPU to host.

When I say "it fails when booting up", what I mean is that there is a color (magenta?) screen for a few seconds, then the screen freezes with these two lines of text:


ProxMox is v8.3.3.
By getting the Ubuntu magenta screen, and by not getting the unable to find a bootable disk error, I know that it is finding the disk and starting to boot from it.
If I boot from the Ubuntu install ISO, it detects that it was installed.

I'm not sure how to proceed to get this VM up and running.
Thanks for your help!

 

[gfngfn256]

I don't have direct experience with a Ubuntu Desktop VM - but as a rule of thumb, first check the minimum requirements & then adapt them for your VM.

So "google being your friend" on searching "Ubuntu 18.04 (Desktop) requirements" leads me to Installation/SystemRequirements from the official Ubuntu site and lists the following:

Recommended Minimum System Requirements
The Recommended Minimum System Requirements here should allow even someone fairly new to installing Ubuntu or GNU/Linux to easily install a usable system with enough room to be comfortable. Simply try Ubuntu CD as a LiveCD first to check the hardware works.


Ubuntu Desktop Edition
2 GHz dual-core processor
4096 MiB RAM (system memory) for physical installs.
2048 MiB RAM for virtualised installs.
25 GB (8.6 GB for minimal) of hard-drive space (or USB stick, memory card or external drive but see LiveCD for an alternative approach)
3D acceleration-capable GPU with at least 256 MB of VRAM
1024x768 or higher resolution display
USB flash drive or DVD drive or for the installer media
Internet access is helpful

1. So you should up the number of cores from 1 to at least 2, I'd probably go with 4.
2. I'd probably up the RAM to at least 4096 MiB (even though it says 2048 MiB RAM for virtualized - this depends on what virtualization & HW).
3. 30 GB disk.

One question that comes to mind - Did you actually initially run the Live CD (iso) with the Desktop environment successfully & then choose to install (from the Desktop), or did you choose an install option from the initial boot option?

Other things that you may need to adjust/play around with in the VM config would be Display & Machine - but leave that for last.

Good luck.

 

[wgshef]

1. So you should up the number of cores from 1 to at least 2, I'd probably go with 4.
2. I'd probably up the RAM to at least 4096 MiB (even though it says 2048 MiB RAM for virtualized - this depends on what virtualization & HW).
3. 30 GB disk.

One question that comes to mind - Did you actually initially run the Live CD (iso) with the Desktop environment successfully & then choose to install (from the Desktop), or did you choose an install option from the initial boot option?

To answer your question first... I booted the VM from the install disk and installed it onto the VM.

What I have done so far:
1. Increased memory to 4GB - still does not boot up.
2. Increased CPU cores from 1 to 2 - no effect.
3. Increased HDD to 15GB - no effect.
4. Tried HDD using SATA, SCSI, VirtIO block - no effect.
4. Increased HDD to 20GB - no effect.
5. Increased HDD to 30GB - still not booting up, but it started going further (getting a magenta screen with "ubuntu" and four dots, initially cycling between the dots, then it froze.
6. Increased CPU cores to 2 to 4 - no effect.

I changed the display to VirtIO-GPU, and then decided to perform a fresh install, what with all of the changes. And... it booted up! Yeah! Nice and fast.

 

[gfngfn256]

I imagined the initial install did not complete successfully & when giving the recommended resources assumed you would fresh install.

Anyway, happy you got it working, maybe mark this thread as Solved.
At the top of the thread, choose the Edit thread button, then from the (no prefix) dropdown choose Solved.