Which version?

This is on a fresh ISO build of 1.3, but looking at Github, the same parts are in the current branch and the equuleus branch of the vyatta-cfg-system repo.

sgdisk man says -n should have a partition number followed by start/end values. Looking at the code this bug is present in all versions 1.2 and above.

I wasn't able to reproduce the issue.
I installed 3 times VyOS 1.3.0 version on Proxmox:

1. Installed using 2.5G, and got expected results
2. Installed using 6.5G and got expected results
3. Installed using default settings (all hdd space), and got expected results.

I also tested similar procedure installing VyOS 1.4-rolling-202201180317 on Virtualbox, and always got root partition as expected

@pvanberlo Can you share more info on how we can reproduce this issue?

I can't add anything else unfortunately, it just doesn't work for me on a physical device whichever value I enter, it always takes the remainder of the free space for the root partition. Manually modifying it works fine.

The man page for sgdisk states:

-n, --new=partnum:start:end

The script contains:

sgdisk -a1 -n1:34:2047   -t1:EF02 \
           -n2:2048:+256M -t2:EF00 \
           -n3:0:0:+$root_part_size -t3:8300 /dev/$ldrive

Which means partnum = 3, start = 0, and end = 0. Start and end being 0 according to the man page results in taking the largest continuous available of diskspace, which is the remainder of the drive. The last part after the last colon seems to be ignored. From the man page:

A start or end value of 0 specifies the default value, which is the start of the largest available block for the start sector and the end of the same block for the end sector.