CentOS/RHEL

“Couldn't find device with uuid [UUID]” - error whith pvs command
The Problem pvs command shows unknown device and pvs couldn't find device with UUID for one of the physical volume # pvs WARNING: Device for PV [UUI...
Hostname change not reflecting in sar report for CentOS/RHEL
The Problem After changing the hostname from geeklab_old to geeklab_new, the sar report still shows the old hostname. # sar -f /var/log/sa/sa09 Linux...
Hostname change not reflecting in /var/log/messages for CentOS/RHEL
The Problem Hostname on server [geeklab_new] does not match hostname recorded in /var/log/messages file. [[email protected]_new]# /bin/hostname geeklab_ne...
“VDO Status Out of space” - Error while creating a VDO disk
The Problem When trying to create a VDO disk the procedure fails with the following error: # vdo create --name=vdoTEST2 --device=/dev/sde --vdoLogica...
How to enable Debug Option For CIFS Module in CentOS/RHEL 7 and 8
Question: How to configure CIFS debug option in Linux servers to provide additional debug information in the client system logs? 1. Take backup of exi...
How to Debug systemd boot process in CentOS/RHEL 7 and 8
Question: How to debug/find, changes or failing commands during boot process? During boot process, when seeing grub boot menu press “e” for edit the g...
How to Enable IPv6 in CentOS/RHEL 8
By default, IPv6 is enabled on CentOS/RHEL 8 systems. However, in certain situations, some users may find it desirable to disable IPv6 support. This p...
“not enough to start the array” - error while staring mdadm RAID array
The Problem After replacing issue disk on software RAID, mdadm Fails to Start the RAID Array with Error - “not enough to start the array” and Software...
How to Disable IPv6 in CentOS/RHEL 8
By default, IPv6 is enabled on CentOS/RHEL 8 systems. However, in certain situations, some users may find it desirable to disable IPv6 support. This p...