Tag: #linux
Writing on GPUs, LLMs, MLOps, Kubernetes — and mindset · 70 posts
70 posts are tagged #linux; the most recent was published on 2026-08-14.
Often tagged together: #kernel 14 #2026-03 10 #cgroups 9 #devops 9 #ebpf 9
Most read in the last 90 days:
Why Installing RHEL Packages in an Air-Gapped Network Is Genuinely Hard — Dependencies Are a Graph, and You Cannot Solve It from the Inside
Explains from first principles why bringing RHEL packages into a locked-down network for finance, government, or defense never ends at "just copy one rpm file". It covers the fact that RPM dependencies are a symbol-level
2026-08-14 · 8 min read #linux#rhel#air-gap#dnf#rpmModules and Version Pinning in an Air-Gapped Network — RHEL 8, 9, and 10 Tell Different Stories
Separates out, against the official documentation, exactly where RHEL 8 modularity goes wrong in an air-gapped network and how that story changes in RHEL 9 and RHEL 10. The key point is that in a local repository built b
2026-08-14 · 10 min read #linux#rhel#air-gap#dnf#modularityBuilding a Local Repository Inside an Air-Gapped Network — createrepo_c, repodata, .repo Files, and GPG Keys
Covers the whole process of turning a transferred bundle of rpms into a working dnf repository inside an air-gapped network. It walks through the structure of the repodata directory that createrepoc produces and the role
2026-08-14 · 10 min read #linux#rhel#air-gap#dnf#createrepoThe Air-Gapped Operations Playbook — Keeping Up with Security Patches, Rolling Back, and Managing CVE Lag
The story that begins after the transfer procedure is finished — the operations chapter, about running an air-gapped network for years. It first makes clear that slow CVE response inside an air-gapped network is not team
2026-08-14 · 13 min read #linux#rhel#air-gap#dnf#securityBringing Container Images into an Air-Gapped Network — podman save and skopeo Are Different Tools
Once the RPM transfer procedure has settled into place, the next request is almost always container images. It starts by separating podman save from the skopeo copy family — one goes through the local image store, the ot
2026-08-14 · 12 min read #linux#rhel#air-gap#podman#skopeoAir-Gap Transfer Procedure and Integrity — Building a Bundle That Still Installs the Same Way Six Months Later
Covers what to put on the transfer medium, what to verify, and how to make that bundle produce the same result when you open it again six months later. It starts with why signature verification matters more in an air-gap
2026-08-14 · 8 min read #linux#rhel#air-gap#rpm#gpgDownloading on the Outside for an Air-Gapped Transfer — dnf download, reposync, and yumdownloader Solve Different Problems
A command-by-command walkthrough of the real procedure for pulling RHEL packages, dependencies and all, on an internet-connected machine so the result can be carried into an air-gapped network. It covers exactly what --r
2026-08-14 · 10 min read #linux#rhel#air-gap#dnf#rpmKorean Dev Blog Curation 1 — Backend and Infrastructure, 14 Posts I Opened and Checked
Fourteen Korean-language backend and infrastructure posts selected for being concrete and reproducible. They cover Istio Sidecar and ServiceEntry, Envoy circuit breaking and routing, the limits of the Prometheus Push Gat
2026-08-12 · 13 min read #curation#큐레이션#backend#infra#istioIt Was Not the CPU That Was Slow but the Syscall Path — Lessons From Turning a Phone Into a Server
Through the case of turning a CMF Phone 1 into a personal infrastructure server, this post lays out where the real cost of a Linux compatibility layer actually lands. After failing to flash postmarketOS, the author kept
2026-08-09 · 9 min read #linux#termux#chroot#proot#self-hostingConnection refused vs. timeout — narrowing the cause at the TCP level
When a connection fails, the terminal hands back one of two messages. Connection refused means the peer returned an RST; timeout means nothing at all answered the SYN you sent. That one-line difference almost entirely de
2026-07-26 · 12 min read #network#tcp#troubleshooting#linux#kubernetesSpace Left but No space left on device — inode exhaustion, deleted open files, reserved blocks
df shows free space, yet a single file cannot be created and ENOSPC comes back. The cause is almost always one of five: inode exhaustion, files that were deleted but are still held open by a process, the reserved blocks
2026-07-26 · 17 min read #linux#filesystem#ext4#troubleshooting#storageCPU steal time and throttling — telling apart the st column in top, burstable credits, and CFS quota
CPU utilization reads 40%, yet p99 latency spikes and the st column in top shows 20%. Three completely different causes hide behind these look-alike symptoms: steal time, where the hypervisor does not hand a physical CPU
2026-07-26 · 17 min read #linux#cpu#cgroups#kubernetes#cloudWhen the OOM Killer Kills a Process — From Decoding the dmesg Report to Telling cgroup OOM Apart
A process vanished without leaving a single log line and the exit code is 137. This post covers how to read the dmesg report left behind by the kernel OOM Killer one line at a time, how the badness score is computed and
2026-07-26 · 18 min read #linux#memory#oom#cgroups#kubernetesdig works but the application fails — start by checking the DNS resolution order
A situation where dig answers normally but only the application cannot find the name is not a bug, it is structure. dig and nslookup bypass /etc/hosts and nsswitch.conf entirely and query the resolver directly. This post
2026-07-26 · 14 min read #network#dns#linux#kubernetes#troubleshootingToo many open files solved for good — why raising ulimit does not help
Your server log fills with accept4 failed (24: Too many open files), you raise ulimit -n, and nothing changes. Behind this single symptom sit three independent limits: the per-process RLIMITNOFILE, the system-wide fs.fil
2026-07-26 · 15 min read #linux#systemd#file-descriptor#troubleshooting#containersWhy Load Average Is Not CPU Utilization — load average 24 With the CPU at 30%
Covers the situation where the load average from uptime is above 24 while the CPU in top does not even reach 30%. Unlike other Unix systems, the Linux load average counts not only runnable (R) tasks but also D state (uni
2026-07-26 · 14 min read #linux#performance#load-average#psi#troubleshootingTalos Linux 1.13 — How a Shell-less Immutable OS Ended Up Shipping a Debug Shell
Talos Linux, the Kubernetes-only immutable OS, shipped 1.13 on April 27, 2026. The release brings a kernel built with Clang/ThinLTO, reproducible disk images, machine-wide container image signature verification, and its
2026-07-17 · 13 min read #linux#kubernetes#talos#immutable-infrastructure#devopsPodman 6.0 — slirp4netns, CNI, and cgroups v1 Removed; macOS's Default Provider Is Now libkrun
On June 24, 2026, Podman 6.0.0 shipped as its first major release in 27 months since 5.0. Support for slirp4netns, CNI, iptables, cgroups v1, and BoltDB was removed all at once, Intel Mac and Windows 10 support was dropp
2026-07-17 · 13 min read #container#podman#docker#linux#macosWhich Release Shipped Wayland Color Management — The Five-Year Deployment Timeline of a Protocol, and the X Server in 2026
Wayland's color-management and HDR protocol, color-management-v1, is the product of a five-year standardization effort — a merge request opened in January 2020 that was not merged until February 2025. This post pins down
2026-07-17 · 14 min read #linux#wayland#hdr#color-management#x11systemd v261 — Staged Rollout Comes to PID 1, Cloud IMDS Absorption, and a Finished dlopen Migration
systemd v261, released 2026-06-19, ships ConditionFraction= (turns a unit on for only a set fraction of the fleet), ConditionMachineTag= (splits machines into rings via machine tags), and a new IMDS subsystem that pulls
2026-07-17 · 16 min read #linux#systemd#devops#cloud#sysadmin