Linux: Guides and Practical Know-how | Page 9 | mironsoft Blog
Linux
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Nov 14, 2025
Adding a third-party repository without scrutiny hands a stranger's signing key root access on your own server. This article shows how GPG signatures actually work under APT and DNF, why PPA installer scripts deserve a read before you run them, and how to systematically audit the package sources already configured on your systems.
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Nov 14, 2025
The proc filesystem is not a collection of ordinary files, it is a virtual window straight into the running Linux kernel. Knowing which files under /proc/[pid] and /proc/sys actually matter lets you read process state, CPU load, memory usage and kernel parameters without relying on top, ps or sysctl, while understanding exactly how those tools work internally.
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Nov 8, 2025
Scrolling through log files at random during an incident wastes valuable time. journalctl brings every systemd log into one place and offers precise filters by service, time range, and severity. This article shows how to combine filters, make the journal persistent, correlate services during an outage, and export logs cleanly for teammates.
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Nov 4, 2025
A memory leak first shows up as a steadily growing RES value in top, followed by ever tighter free memory and eventually an OOM kill in the middle of the day. Simply restarting the affected service buys time, not insight. This guide shows how to use built-in tools like smaps_rollup, smem and pmap to systematically find out which process is losing memory and where in the code or configuration the cause lies.
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Nov 3, 2025
The virtual /proc filesystem exports kernel internals as seemingly ordinary files. Reading /proc/[pid]/status, /proc/meminfo, and /proc/loadavg directly with built-in Bash tools produces lightweight diagnostic scripts that need no external process call and work fine in minimal container images without extra tooling.
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Nov 1, 2025
Anyone who wants to systematically solve network problems on a Linux server needs a clear understanding of interfaces, routing and name resolution. This article explains how ip addr and ip link manage interfaces, how the routing table works with ip route, how resolv.conf and nsswitch.conf control DNS, and the fixed order in which connectivity failures can reliably be narrowed down.
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Nov 1, 2025
An overloaded web server is rarely down to application code alone. More often, it comes down to mismatched operating system limits and undersized PHP-FPM pools that collapse under real traffic. This article shows, in practical terms, how to correctly size Nginx worker processes, file descriptor limits, the TCP backlog, and pm.max_children based on the memory actually available, and how to back up every single change with real benchmark numbers instead of relying on guesswork.
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Oct 27, 2025
nice and ionice only lower the priority of background jobs, but do not prevent them from briefly occupying entire cores. CPU pinning goes a step further: it reserves specific cores exclusively for PHP-FPM workers, while reindexing and cron are only allowed to run on other cores.
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Oct 24, 2025
Anyone who randomly changes configurations and restarts services during an incident extends the downtime and leaves behind contradictory traces for the root cause analysis. A fixed process of availability verification, change comparison, resource checks, and systematic log analysis gets to the cause faster, produces traceable documentation for the postmortem, and makes clear when to escalate instead of digging alone indefinitely.
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Oct 21, 2025
Docker containers are not magic and not lightweight virtual machines either, they are ordinary Linux processes that the kernel starts with a restricted view of processes, networking, and the filesystem through namespaces, while cgroups cap their resource usage. Understanding both mechanisms lets you inspect and reason about any running container directly from the host.