coredumpctl: Debug a Crash-Looping Service
Your service dies and restarts forever. Read the core dump instead of the restart log: coredumpctl, gdb, debuginfod, storage limits, and Docker containers.
Tag: linux
All the articles with the tag "linux".
systemd-tmpfiles: Runtime and Cache Dirs
Service dies after reboot because /run/myapp vanished? Learn tmpfiles.d line types, Age cleanup, overrides, and when RuntimeDirectory= is the better pick.
NVMe SMART: Reading Wear Before It Dies
How NVMe wear leveling works and which SMART health log fields show it: Percentage Used, Available Spare, media errors, TBW math, smartctl vs nvme-cli.
Read-Only Docker Containers: What Breaks
Turn on read_only: true and watch nginx, Postgres, Redis, Python and Node fail in specific ways. Real errors, plus the minimum tmpfs and volume set for each.
Firewall Rule Audit: Find the Dead Rules
Find unused firewall rules on a Linux box with nftables counters, then retire them safely with a snapshot-and-diff routine, a jq script, and a systemd timer.
Idle Watts Audit: Halve Your Lab's Draw
Find what pins your home lab at high idle power: ASPM, package C-states, disks, NICs, and chatty containers. Measure at the wall and fix one blocker at a time.
One PC, Many Players: Steam Headless
Run several Steam Headless v2 containers on one Linux box so a household can play at once, each seat streamed with Moonlight. Compose file, numbers, gotchas.
AppArmor Profiles for Docker, Step by Step
Docker puts every container under the docker-default AppArmor profile. See what it blocks, then build a tested nginx profile with audit deny and complain mode.
Btrfs Send/Receive: Incremental Backups
Back up btrfs with send and receive: full and incremental streams over SSH, parent snapshots, restores, failure modes, and btrbk to automate the whole loop.
Sync Game Saves Without a Cloud Account
Sync game saves between PC, Linux, and Steam Deck without a cloud account. Ludusavi backs up the saves, Syncthing moves them, and Proton paths get sorted out.
zstd vs lz4 vs gzip vs xz: Measured
zstd -3 compresses 4 to 6x faster than gzip -6 with smaller files. At the top end, xz -6 beat zstd -19 on speed. 19 configs, 4 public data sets, measured.
Network Namespaces by Hand, No Docker
Rebuild Docker's bridge network with ip netns, veth pairs, a Linux bridge and nftables NAT. Six iproute2 commands, three nft rules, and a 2 AM debugging edge.