#linux

A one-liner with awk that counts running, paused, idle, and shut-off KVM guests from virsh list --all output. Quick health check on a busy hypervisor.

Specific UID numbers and ranges of numbers are used for specific purposes by Red Hat Enterprise Linux. • UID 0 is always assigned to the superuser account, root. • UID 1-200 is a range of "system users" assigned statically to system processes by Red Hat. • UID 201-999 is a range of "system…

Issue: You may have requirements to update the existing Infrastructure Hosts on your OpenNebula cluster that are currently hosting virtual machines (VMs), but the hosts name can't updated Here is a scenario that illustrates this case: * Existing host: compute1.sgp.example.com * Change host to:…

TL;DR: 1. S0: Also known as the working state, the computer is fully operational with the CPU executing instructions, devices powered on, and the display active. 2. S1: Also known as the sleep state, the CPU stops executing instructions, but the memory and system state are still powered on to…

Straightforward, if you get these error messages: Jan 26 10:27:33 c**.com lldpd[3083]: unable to send packet on real device for ens9f1: No such device or address Jan 26 10:27:35 c**.com lldpd[3083]: unable to send packet on real device for enp132s0f0: No such device or address Jan 26 10:27:35…

Suatu ketika, saya dihadapkan oleh aplikasi infrastruktur cloud yang tidak menampilkan progress ketika melakukan migrasi VM. There is no progress bar, the way is to see that the VM is being migrated is the state as you said. Take in account that each migration is different and is an synchronous…

Kadang kala beberapa command Linux yang kita install tidak tersedia secara default sebagai service. Saya ambil contoh, Node Exporter Untuk penjelasan lebih detail tentang Node Exporter saya akan jelaskan di tulisan selanjutnya. Jadi untuk mengatasi hal ini, kita perlu membuat service command itu…

Intel's open-source ledmon lets you blink the LED on a specific drive in a server enclosure — handy when you need to physically locate a disk before pulling the wrong one.

System Activity Reports — using sar to investigate a sudden server crash. Where the data lives, how to generate plain-text reports, and a free chart tool to actually make sense of the numbers.

Quick reference for restricting access in Apache: the order/deny/allow syntax of 2.2 vs the Require syntax of 2.4 — almost the same problem, almost the same words, different config.

Reload Logstash pipeline config without restarting the service — just send SIGHUP to the running process and watch the log confirm the reload.

A scratchpad of one-liners I keep typing — find files older than N days, list IPs, and the others I'm too lazy to memorize properly.