How to set a grub password using in a single mode system

Step1=

Grub –md5-crypt = type this command in a single mode & press enter key.

Step2=

Set a password & copy a encryted passwd & enter in

Vim /boot/grub/grub.conf

Step3=

Belows hidden menu paste a passwd & wq to save & exit. See like that in a belows.

hiddenmenu

#password --md5 $1$UlfoC1$MvkSL3jJV2hDMv39v16IW1

Step4=

Reboot the system..& enter in a single mode again

Here…type (p) asked for passwd. Give any password.

How to edit grub password

Step1=

Restart a System & enter in a grub & edit to grub press “e ” press Tab key here & type“resecure” & press Enter key & then press “b” for booting a system.

Step2=

Select URL or cdrom from where u have to installed a operating system.

ftp://192.168.0.254/pub/rhel6/dvd

ls ---to check files

chroot /mnt/sysimage

ls --- to check file system here showing booting process.

Step3=

Vim /boot/grub/grub.conf…..

Delete a password from grub.conf file , which is set below a hidden menu , Like this.

#password --md5 $1$UlfoC1$MvkSL3jJV2hDMv39v16IW1

After that…….save & exit ….& reboot a system .

Step1=

1. Mkdir /dir = create a directory
2. Run script /etc/bashrc (umask value root = 022 & user = 002)
3. Deduct umask value from base permission then set a default permission.

Step1=

1. Mkdir /dir = create a directory
2. Run script /etc/bashrc (umask value= root = 022, user = 002)
3. Deduct umask value from base permission , then set a default permission.

Chmod –R 777 /dir = permission set to be existing files only & for a new files need to run again this command to set a permission .

Chmod -R u=wrx,g=wrx,o=wrx /dir = permission set to by using words.

Chmod -R g-w,o-w /dir = remove a write permission from group & other users.

Chmod -R g+w,o+w /dir = add a write permission to group & other users.

Chmod -R ugo=wrx /dir = we can set permission by this way also to a directory.

Chgrp redhat /dir = to change a group owner permission.

# special permission set in word “s” & in numeriacal “2” character used to set a special permission.

Set gid:-

Chgrp -R redhat /dir = change a group owner.

Chmod g+s /dir = set a special permission to a group

Chmod –R 2755 /dir = set a special permission to a parent & child directory using numerical character

Sticky bit permission set:-

• Chmod –R 1777 /dir = set a sticky bit permission to a directory.
• Chmod o+t /dir = set sticky bit permission to other users using “t” character.

(-R = permission format & -s = group permission format)