Tag: linux

Master SSH ControlMaster, ControlPath, and ControlPersist. Reuse connections for lightning-fast SSH, SCP, and rsync operations.

Why Linux kills your app with no warning. Understand the OOM killer, read dmesg logs, and shield critical processes with oom_score_adj and swap.

Practical find command examples: -mtime, -newer, -type, -exec vs xargs, -not, size filters. The patterns you google every time.

Master ~/.ssh/config: Host aliases, HostName, User, Port, IdentityFile, ProxyJump. Stop typing long SSH commands. One-line setup.

kill -9 skips cleanup and leaves locks and half-written data behind. SIGTERM vs SIGKILL, the graceful shutdown pattern, pkill, and how systemd does it.

Understand Linux umask: what it is, how 022 and 027 work, calculating file permissions, and why it matters for shared directories and security.

The /proc filesystem is a live window into every running process on Linux. Debug PIDs, file descriptors, memory, and limits with no extra tools installed.

Compare zram (compressed RAM) and traditional swap files. Learn when each works, setup, and real-world performance trade-offs for memory-constrained systems.

Use strace to trace system calls and debug mysterious permission errors, missing files, and network issues without ever reading source code.

Copy and paste from the Linux terminal without a mouse. Master xclip, xsel, wl-copy, and integrate clipboard with tmux and SSH.

lsof shows every open file, socket, and port on the box. Find what holds a port, trace deleted files still eating disk, and see what a service owns.

Manage Linux process priority with nice (CPU) and ionice (I/O). Learn priority levels, renice running processes, and avoid tanking server performance.