CentOS

LINUX – nmcli command examples (cheatsheet), compare nm-settings with if-cfg file

Table of Contents Understanding nmcli Compare nm-settings with ifcfg-* directives (IPv4) Compare nm-settings with ifcfg-* directives (IPv6) Brief list of nmcli commands syntax nmcli command examples (cheatsheet) 1. Check if…
CentOS

CentOS – Installer just goes black screen on Centos8

Problem: During installation of CentOS the installer screen goes black. The terminal multiplexer is running in virtual console 1. To switch from the graphical installation environment to tmux, press Ctrl+Alt+F1. To go back to the main…

How to force fsck at every boot in Linux

In /etc/init.d/checkfs.sh is the line if [ -f /forcefsck ] || grep -s -w -i "forcefsck" /proc/cmdline, so providing forcefsck on the kernel command line or generating a /forcefsck file on shutdown should cause an fsck on the next reboot. To…
CentOS

LINUX – Network Throughput Tuning

General Approach To check what setting your system is using, use 'sysctl name' (e.g.: 'sysctl net.ipv4.tcp_rmem'). To change a setting use 'sysctl -w'. To make the setting permanent add the setting to the file 'sysctl.conf'. [crayon-68a79ca4887a5523027644/] More…
CentOS

CentOS – How do I safely delete old kernel versions ?

package-cleanup: Using package-cleanup command which is a part of yum-utils package we can uninstall any number of old kernels automatically. As an example using --oldkernels --count=2 option with package-cleanup command the command…
ZFS ZOL

ZFS – CENTOS Downgrade

ZFS - Downgrade Commands for Centos: To do the downgrade/re-install dance: [crayon-68a79ca488cd2879259470/] [crayon-68a79ca488cda548544564/] [crayon-68a79ca488cdd352275137/]
ZFS ZOL

ZFS – Tuning

ZFS tuning for SAS3 Storage Tank [crayon-68a79ca488fad490781108/] ZFS tuning for SAS3 ALL SSD + nVME Storage Tank [crayon-68a79ca488fb9470742433/] Some more good advice: SvennD ZFS-Discuss
ZFS ZOL

ZFS – SNMP

ZFS - SNMP Extend Commands: [crayon-68a79ca489308494126249/] LibreNMS: https://community.librenms.org/t/zfs-support/1839 https://docs.librenms.org/#Extensions/Applications/#zfs

CentOS – NIC Teaming with LACP

A Comparison of Features in Bonding and Team Feature Bonding Team broadcast Tx policy Yes Yes round-robin Tx policy Yes Yes active-backup Tx policy Yes Yes LACP (802.3ad) support Yes (active only) Yes Hash-based…

Debian – How do you select the fastest mirror from the command line?

I want to update my sources.list file with the fastest server from the command line in a fresh Ubuntu Server install. I know this is trivially easy with the GUI, but there doesn't seem to be a simple way to do it from from the command line? [crayon-68a79ca4899c8026505352/] Automated…