RHEL 8 - Troubleshooting with Rescue Option

 Using the Rescue Option in RHEL 8.

First restart your server from the installation disk and select the Troubleshooting menu option.

From the Troubleshooting menu, select Rescue Red Hat Enterprise Linux System.  This option doesn't not overwrite your current configuration but only to load a rescue system.

 

The rescue system prompts user that it will try to find an installed Linux system and mount it on /mnt/sysimage.  Press 1 to accept the Continue option.

Once a valid RH OS installation was found and user is prompted that the system has been mounted under /mnt/sysimage.  At this point, user can press Enter twice to access the rescue shell.

At this point, your Linux installation is accessible through the /mnt/sysimage directory.  User can type chroot /mnt/sysimage.  At this point user  have access to the system root file system and you can access all tools that is needed to repair access of the system.

Once repair is completed, user can type exit and reboot to restart the system in a normal mode.

bzip2: Cannot exec: No such file or directory

Error when trying to create tar.bz2 Archive File in CentOS 7

The following is the error output when trying to create tar.bz2 file in CentOS7:

$ tar cvfj testfile.tar.bz2 ./testfile*
tar (child): bzip2: Cannot exec: No such file or directory
tar (child): Error is not recoverable: exiting now
tar: Child returned status 2
tar: Error is not recoverable: exiting now
$

First step is to check if the package is installed or not.
$ sudo yum list installed | grep bzip2

If package is not installed, please run the following:
# yum install bzip2
# exit

Then create tar.bz2 file.
$ tar cvfj testfile.tar.bz2 ./testfile*

Commands to check CentOS version

These are the commands on CentOS to check version:

# hostnamectl
# rpm --query centos-release
# cat /etc/centos-release
# cat /etc/os-release
# cat /etc/redhat-release
# cat /etc/system-release

Note:
# uname -a
and
# uname -r
will not give the OS version in detail.

[root@localhost slean]# hostnamectl
      Static hostname: localhost.localdomain
              Icon name: computer
                   Chassis: n/a
            Machine ID: e6450196561343d9976ba0d9c29c54c0
                  Boot ID: 0ddca677a08a44019c0f9b71fec2882a
         Virtualization: vmware
  Operating System: CentOS Linux 7 (Core)
       CPE OS Name: cpe:/o:centos:centos:7
                    Kernel: Linux 3.10.0-229.11.1.el7.x86_64
           Architecture: x86_64
[root@localhost slean]#

Similar result from running # hostnamectl on Oracle VirtualBox

[root@localhost ~]# hostnamectl

   Static hostname: localhost.localdomain

         Icon name: computer-vm

           Chassis: vm

        Machine ID: ec0ea531f8894f84b9d5266ee38dfd8a

           Boot ID: d1fa0335dab445fca139710b318734a8

    Virtualization: oracle

  Operating System: CentOS Linux 8 (Core)

       CPE OS Name: cpe:/o:centos:centos:8

            Kernel: Linux 4.18.0-193.14.2.el8_2.x86_64

      Architecture: x86-64

[root@localhost ~]#

Another way to get the CentOS version is by 

[slean@localhost ~]$ cat /etc/os-release

NAME="CentOS Linux"

VERSION="7 (Core)"

ID="centos"

ID_LIKE="rhel fedora"

VERSION_ID="7"

PRETTY_NAME="CentOS Linux 7 (Core)"

ANSI_COLOR="0;31"

CPE_NAME="cpe:/o:centos:centos:7"

HOME_URL="https://www.centos.org/"

BUG_REPORT_URL="https://bugs.centos.org/"

CENTOS_MANTISBT_PROJECT="CentOS-7"

CENTOS_MANTISBT_PROJECT_VERSION="7"

REDHAT_SUPPORT_PRODUCT="centos"

REDHAT_SUPPORT_PRODUCT_VERSION="7"

[slean@localhost ~]$ 

The next 3 commands give the same output result

[slean@localhost ~]$ cat /etc/centos-release

CentOS Linux release 7.1.1503 (Core) 

[slean@localhost ~]$ 

[slean@localhost ~]$ cat /etc/redhat-release

CentOS Linux release 7.1.1503 (Core) 

[slean@localhost ~]$ 

[slean@localhost ~]$ cat /etc/system-release

CentOS Linux release 7.1.1503 (Core) 

[slean@localhost ~]$ 

Source: https://linuxconfig.org/how-to-check-centos-version