Latest Articles - Page 26

Fix "Pulling is not possible because you have unmerged files" with git status, resolve conflict markers, git add, git commit or --continue, or abort the in-progress merge, rebase, or cherry-pick.

Git rebase explained with ASCII flow diagrams, feature-branch replay onto main, conflict resolution with git status, remote rebase, force-with-lease, interactive rebase, and when to use rebase instead of merge.

Install Prometheus from the upstream Linux binary on RHEL-family hosts, add Grafana from the official RPM repository, enable both with systemd, open firewalld ports 9090 and 3000, and connect Grafana to Prometheus on the …

Hexagonal architecture in Go with a Gin messaging API, GORM v2 and Valkey adapters, folder layout, inbound and outbound ports, curl verification, and when ports-and-adapters beats layered CRUD.

Configure software RAID 0 (striping) in Linux with mdadm on two partitions, format with ext4, mount the volume, and persist it across reboot.

Learn what the trailing dot after Linux permissions means in ls -l output, how it differs from a plus sign, and when to use ls -Z or restorecon instead of removing SELinux labels.

Copy files between Linux servers with scp, rsync, SFTP, tar over SSH, ncat, curl, and wget using tested push, pull, sync, and HTTP examples.

Check internet connectivity on Linux with curl to google.com, ping, DNS tools, and a shell script pattern — then work down routing and firewall layers when the quick check fails.

Configure software RAID 5 in Linux with mdadm on three partitions — distributed parity, left-symmetric layout, initial recovery, and creating larger arrays with spares.

Configure software RAID 4 in Linux with mdadm on three partitions — dedicated parity disk, parity initialization, format with ext4, and mount.

Configure linear RAID (append mode) in Linux with mdadm on two partitions — fdisk setup, create the array, format with ext4, mount, and persist across reboot.

Create a dropdown list in SoftMaker PlanMaker with input validation for in-cell lists or a form object dropdown linked to a sheet range and result cell.

Configure software RAID 10 (RAID 1+0) in Linux with mdadm by mirroring two disk pairs into RAID 1 arrays, striping them with RAID 0, and mounting the resulting volume.

chmod 777 gives owner, group, and everyone else read, write, and execute or search permission (rwxrwxrwx); learn why that is risky, what chmod -R 777 does, and which modes like 755 or 775 to use instead.

Check last password change and expiration date on Linux with chage -l, chage -i -l, passwd -S, and /etc/shadow, including status codes and local vs LDAP users.

Check disk type in Linux with lsblk ROTA and TRAN, sysfs rotational, udevadm, lspci, and optional smartctl or nvme tools to tell HDD from SSD, NVMe from SATA, and when virtual or RAID storage hides the real media.

Check if a Linux server is physical or virtual with systemd-detect-virt, virt-what, dmidecode, DMI sysfs files, and lscpu, including VM vs container detection and when tools disagree.

Capture SSH client and sshd strace logs with ssh -vvv and sshd -ddd on an alternate port, analyze syscall failures, optionally attach strace -f -p to the running daemon, and collect matching tcpdump evidence.

Fix Linux errno 99 (EADDRNOTAVAIL): when bind() fails because the IP is not local, when Docker publishes to a missing host address, when services start before the interface is ready, and when connect() exhausts ephemeral …

Batch resize images in Linux with ImageMagick mogrify and magick, including aspect-ratio control, non-destructive output directories, mixed JPG and PNG folders, recursive trees, and optional format conversion.

Fix bash: curl: command not found by installing the curl package with apt, dnf, pacman, zypper, or apk, or by restoring /usr/bin and /bin in PATH when curl is already installed.

Learn what systemd is in Linux, how units and targets fit together, and which systemctl commands to run first. This beginner tutorial focuses on concepts and points to dedicated guides for listing services, targets, …

Back up and restore GPT or MBR partition tables in Linux with sfdisk --dump, clone a layout to another disk, and save raw partition-table sectors with --backup-pt-sectors without touching filesystem data.

Compare the best automation testing tools in {year} for Linux and CI pipelines, including Playwright, Selenium, Cypress, Appium, pytest, REST Assured, Robot Framework, k6, and JMeter, with guidance on test types, …

Compare the best open source and self-hosted application performance monitoring tools in {year}, including SigNoz, Apache SkyWalking, OpenObserve, Coroot, Glowroot, and the Grafana stack, with guidance on OpenTelemetry …

Automate SFTP file transfers in Linux shell scripts using sftp batch mode with SSH keys, or password authentication with sshpass or expect when keys are not available.

Install ARPACK runtime and development packages on Ubuntu, Debian, and RHEL-family Linux from distribution repositories, verify libraries with dpkg or rpm and pkg-config, and link a sample Fortran program against …

Fix “another app is currently holding the yum lock” and modern DNF lock messages on RHEL and Fedora. Find the holding PID, wait safely, and clear stale metadata or RPMDB locks on DNF4 and DNF5.

Add a user to a supplementary group in Linux with usermod -aG, gpasswd -a, or adduser on Debian. Verify with id, apply changes with newgrp or re-login, and avoid the missing -a mistake.

Configure BIND primary and secondary DNS on RHEL-family Linux with allow-transfer, slave zones, named-chroot on Rocky Linux 8, and dig verification after AXFR zone replication.