utmp Format

From: support
Date: Thu Aug 01 2024 - 12:44:22 EST


I've noticed a difference in the size of the `utmp` struct between Linux 6.1.0-22-amd64 and 6.1.0-23-cloud-arm64. No doubt there are differences between other unices as well. Is there a reason this is still a binary log? On 6.1.0-22-amd64, it seems to be 384 bytes long, while the average line length from `utmpdump` is only 125 bytes, so it's not a space savings.

My primary concern is forensics. There is no consistent and reliable way to read wtmp/btmp outside of the installation that created it.

JS