mkfs.ext4 zeroes the entire inode table and journal at format time
unless told otherwise. On an 8 GiB work disk that's roughly 500-700ms
of host CPU/IO per 'banger vm create', for a one-time small per-write
penalty inside the guest the first time it touches an unwritten
inode that nobody can perceive.
Centralise the canonical mkfs -E option list as
system.MkfsExtraOptions and use it everywhere banger calls mkfs.ext4
on a VM-internal image: the no-seed work disk, MaterializeWorkDisk,
BuildWorkSeedImage, and the imagepull rootfs builder. The work-disk
paths feed vm create directly; the others are one-off but still
benefit from the faster format.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>