install/58203: Default amd64 install runs out of space on 8GB disk

[abs%absd.org@localhost]

>Number:         58203
>Category:       install
>Synopsis:       Default amd64 install runs out of space on 8GB disk
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    install-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Apr 27 15:25:00 +0000 2024
>Originator:     David Brownlee
>Release:        NetBSD 10.0
>Organization:
>Environment:
NetBSD   10.0
>Description:
Attempting to install NetBSD/amd64 10.0 on an "8GB" (7.5GB) USB key, with empty MBR (no partitions), gives a 0.5GB root and 7.1GB swap, and attempting a full install runs out of space without any warning.

>How-To-Repeat:
Attempting to install NetBSD/amd64 10.0 on an "8GB" (7.5GB) USB key, with empty MBR (no partitions)

Selected
- "Use the entire disk"
- "Use default partition sizes"

System was partitioned with
a: 555MB /
b: 7123MB swap
e 128MB MSDOS

Attempting to install everything runs the 555MB out of space
>Fix:
a) In the case of smaller target disks, the default should probably still try to make a root filesystem larger enough for a default install

b) Potentially show a warning (but allow the user to continue if they "know what they are doing") if the root filesystem is smaller than that needed for a default install