I created a QEMU virtual machine intending to install Ubuntu Server 20.04. The host is a Proxmox 6.x Debian system. The virtual machine parameters are:
- 2 CPU cores, 1 socket
- 512 MB ram, ballooning device
- 32GB SCSI Hard Drive, VirtIO SCSI controller
- VirtIO ethernet device
Note: these are all the Proxmox defaults from the VM creation dialog, for a Linux 5.x guest.
Once I start the VM, an Ubuntu screen comes up. Then, the following error appears:
Initramfs unpacking failed: write error
Failed to execute /init (error -2)
Kernel panic - not syncing: No working init found. Try passing init= option to kernel. See Linux Documentation/admin-guide/init.rst for guidance.
Best Answer
The recommended minimum RAM for an Ubuntu Server installation is 1GB.
I was able verify that using the parameters above, but with 1GB of RAM, allowed the system to boot properly.
From the comments Installation with 768MB works, too (as of 2021-01-24). After installation you can reduce the RAM assignment, the server will run fine (depending on your use-case of course) with 512MB.