Containers
/proc/self/tags
4 min Proposing process-relative cgroup tags after an earlier namespace question exposed an isolation guarantee that never existed.
Propagation is a direction
3 min Mount propagation is two separate trust decisions, not one switch—the argument from an lxc-users thread about read-only roots.
Read mountinfo first
3 min Before explaining a mount, read /proc/self/mountinfo—the kernel’s live table shows what mount(8) output hides.
The prompt that asks the kernel
2 min A bashrc derived container identity from /proc/self/cgroup and prefixed the prompt with VPS[name]—no environment variable involved.
Containers in 2010
6 min vps-lxc: templates as btrfs subvolumes, containers as writable snapshots, and the host-local image model I built around them.
runlevel(8) reads whatever utmp you point it at
2 min A container supervisor read a guest’s shutdown intent from the guest’s own utmp, because runlevel accepts an alternate path.