Question: There is a need to install the pip software package in CentOS/RHEL. How to install the same? For CentOS/RHEL 7 CentOS/RHEL 7 uses python 2.7 as the system version of python. Python 2.x is not maintained or supported since 2020, using it in applications is not recommended. Python 3 should be used whenever possible. […]
Linux
How to debug systemd boot process in CentOS/RHEL 7 and 8
Question: How to debug/find, changes or failing commands during the boot process? 1. During boot process, when seeing grub boot menu press “e” for edit the grub, then scroll down until you see boot entry: echo “Loading Linux… linux16 /vmlinuz-XXX root=XXXro crashkernel=auto rd.lvm.lv=rhel/root rd.lvm.lv=rhel/swap rhgb quiet LANG=en_US.UTF-8 2. On the line with “linux” remove following […]
How to Convert a Directory to Partition in Linux
The goal of the post is to achieve moving the home directory into a newly added disk that has a dedicated Partition. 1. Add the new disk and create the necessary partition(for example sdb1). 2. Move the home folder into one of the partitions. To use a filesystem, it has to be mounted to the […]
“BAD PASSWD : is too simple” – error during password change in CentOS/RHEL 7 and 8
Question: How too avoid the warning “BAD PASSWD : is too simple” when changing password in Linux? 1. Modify the configuration file /etc/pam.d/password-auth and /etc/pam.d/system-auth to set the password complexity. # vi /etc/pam.d/password-auth The following information are displayed. auth required pam_env.so auth sufficient pam_unix.so try_first_pass nullok auth required pam_deny.so account required pam_unix.so #password requisite pam_cracklib.so […]
How to allow all traffic from a server using firewalld in CentOS/RHEL
This post outlines steps to add a host or network range to a trusted zone, in firewalld, to allow all traffic regardless of the destination port. To create a rule to allow all traffic from a node or network range, it should use the trusted network zone in firewalld. 1. To add an host to […]
How to Configure firewalld Logging in CentOS/RHEL 8
Question: How to enable logging in firewalld for CentOS/RHEL 8? 1. Edit the /etc/firewalld/firewalld.conf and change the “LogDenied” line to the following: # vi /etc/firewalld/firewalld.conf LogDenied=all 2. Edit the /etc/sysconfig/firewalld and add or change the “FIREWALLD_ARGS” line to the following: # vi /etc/sysconfig/firewalld FIREWALLD_ARGS=–debug=10 3. Restart the firewalld service: # systemctl restart firewalld.service 4. Check […]
“Failed to Synchronize Cache For Repo ‘repo_name’, Ignoring This Repo” – CentOS/RHEL 8 error
The Problem While installing package or listing using dnf or yum commands getting below errors: # dnf repolist .. Failed to synchronize cache for repo ‘xxx’, ignoring this repo. Failed to synchronize cache for repo ‘yyy’, ignoring this repo. While checking the dnf logs: # tail -f /var/log/dnf.log 2019-08-12T10:58:13Z INFO — logging initialized — 2019-08-12T10:58:13Z […]
How to delete unused kernels and keep only the running kernel in CentOS/RHEL
Question: How to keep only running kernel in a CentOS/RHEL Linux system? Keeping less than 2 kernels in a Linux system is strongly not recommended. There are several reasons for this recommendation: If an installation of a new kernel is interrupted or aborted in any before it completes successfully, rebooting the system with that kernel […]
How to Delete unnecessary Entry in /etc/shadow
Question: How to remove all the unnecessary user entries in /etc/shadow file. 1. Create a backup copy of /etc/shadow file. # cp -p /etc/shadow /etc/shadow.backup 2. Ensure the user is not existing anymore in /etc/password file. # cat /etc/passwd | grep [userid] 3. Edit the /etc/shadow file, look for the line and remove the unnecessary […]
User Account “systemd-bus-proxy”
This post provides information about the user account systemd-bus-proxy. The user account systemd-bus-proxy was used in the past by systemd-bus-proxyd service. systemd-bus-proxy:x:999:997:systemd Bus Proxy:/:/sbin/nologin Starting systemd-219-32, bus-proxyd was removed. Therefore, it is no longer in use in later systemd versions. * Mon Feb 20 2017 Lukas Nykryn – 219-32 … – remove bus-proxyd (#1317518) NOTE: […]