Month: July 2020

Cool additions to the Gnome Desktop

Go to https://extensions.gnome.org and install the browser extension.
Use firefox, not chrome, chrome goes haywire when you install the browser extension
Then look for the following extensions and install them.

  • Dash to Panel
    Arc Menu

see original article here:
https://www.reddit.com/r/Fedora/comments/hr3j6k/fedora_32_is_awesome/

Find and replace text within a file using sed

Find and replace text within a file using sed

The procedure to change the text in files under Linux/Unix using sed:

  1. Use Stream EDitor (sed) as follows:
  2. sed -i 's/old-text/new-text/g' input.txt
  3. The s is the substitute command of sed for find and replace
  4. It tells sed to find all occurrences of ‘old-text’ and replace with ‘new-text’ in a file named input.txt
  5. Verify that file has been updated:
  6. more input.txt

Resetting the Root Password of RHEL-8

Resetting the Root Password of RHEL-8

Resolution
1) Break the boot sequence by adding ‘rd.break’ at kernel stanza in grub. To do this, restart your system and when the GRUB splash screen comes:

  1. Select/highlight the kernel you wish to boot using the up/down arrow keys.
  2. Press the e key to edit the entry.
  3. Select/highlight the line starting with the word kernel or linux.
  4. Press the e key to edit the line.
  5. Add ‘rd.break’ at the end.
  6. Press ENTER to accept the changes.
  7. Press the ‘ctrl + x’ key to boot the kernel with the modified command line.

2) The system will provide a shell which will be from initramfs:

.
.
Entering emergency mode. Exit the shell to continue.
Type "journalctl" to view system logs.
You might want to save "/run/initramfs/rdsosreport.txt" to a USB stick or /boot
after mounting them and attach it to a bug report.
switch_root:/#

3) Root filesystem will be mounted read-only at ‘sysroot’ directory:

switch_root:/# mount | grep -i sysroot
/dev/mapper/rhel-root on /sysroot type xfs (ro,relatime,attr2,inode64,noquota)

4) Remount it with read-write mode:

switch_root:/# mount -o remount,rw /sysroot

5) Chroot into it:

switch_root:/# chroot /sysroot/
sh-4.4#

6) Change the password:

sh-4.4# passwd
Changing password for user root.
New password:
BAD PASSWORD: The password is shorter than 8 characters
Retype new password:
passwd: all authentication tokens updated successfully.

 
7) Relabel the filesystem:

sh-4.4# touch /.autorelabel

8) Exit from the shell:

sh-4.4# exit
exit
switch_root:/#
switch_root:/# exit

9) The system will continue the paused booting sequence:

.
Starting Relabel all filesystems...
[  OK  ] Started Manage Sound Card St
localhost login: