A school, its servers, and the notes
Linux, written down before it is forgotten.
Twenty years of building the Linux side of a school: one directory for identity, one home directory per student, and a lab fleet that can be rebuilt from a playbook. The configuration is in here, not just the summary.
6 of 6 ports in use
no uplink spare
Latest writing
Three notes to start
01
Setting up a Linux school
Identity, homes, and the fleet: the LDAP tree, the SSSD clients, the NFS export, the autofs maps, and what happens on a student's first login.
02
A domain, a site, and an inbox
One file on Pages, mail that never becomes a mailbox, the catch-all that stops at the apex, and the two-message test that proves routing works.
03
Real-time programming notes
Deadlines, jitter, and the parts of a general-purpose kernel that quietly ruin both. Budgets, priority inversion, isolation flags, and a lock-free ring.
Fig. 1 — the shape of it
One directory. One home. A lab you can rebuild.
Students authenticate once, against one directory, and their files follow them to any machine in the building. Nothing is stored on the machine in front of them, which is why re-imaging a room takes an evening and not a week.