fstab file define the mount points for partition. Before you can use the files in a directory, you need to mount that directory on a partition formatted to some readable filesystem. Linux normally automates this process using the /etc/fstab configuration file. You may encounter problems if connections are lost or media is removed. This cause error and these error are highly tested in RHCE exam.
RHCE Exam Questions
You are giving RHCE exam. Examiner gave you the Boot related problem and told to you that make successfully boot the System. When you started the system, System automatically asking the root password for maintenance. How will you fix that problem?
Troubleshooting of fstab
In this practical we will discuss how a faulty fstab file case error and how can you remove them.
Take back up and Open /etc/fstab file from vi command
default fstab file look like this
Description of /etc/fstab by Column, Left to Right
Lists the device to be mounted
Notes the directory where the filesystem will be mounted
Describes the filesystem type. Valid filesystem types include ext, ext2, ext3, msdos, vfat, devpts, proc, tmpfs, udf, iso9660, nfs, smb, and swap.
Dump Value Either 0 or 1. A value of 1 means that data is automatically saved to disk by the dump(8) command when you exit Linux.
|Filesystem Check Order|
Filesystem Check Order Determines the order that filesystems are checked by fsck(8) during the boot process. The root directory (/) filesystem should be set to 1, and other local filesystems should be set to 2. Removable filesystems such as /mnt/cdrom should be set to 0, which means that they are not checked during the Linux boot process.
Now make some change in /etc/fstab file so it could be faulty as I did in this file
Save the change and restart the system
After restart System will automatically ask the root password for maintenance
Give root password , and remount system for read, write and open /etc/fstab file
Correct the fstab file and save the change [ change will not save if you did not mount the system for read and write]
After saving the change reboot system
This time system will boot without any error.