Understanding /etc/fstab file and its dump option. Is it of any significance ?

Today in this article, we will see the importance of dump option in /etc/fstab file and will understand if its of any importance.

To understand this, lets first look at an example entry of /etc/fstab file and understand its fields.

1. Check out fstab file.

root@host-1-105 ~]# cat /etc/fstab

#
# /etc/fstab
# Created by anaconda on Mon Sep  8 08:09:05 2014
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
/dev/mapper/centos_lvm-root               /                       xfs     defaults        1 1
UUID=f3b744e4-e754-4842-93d1-43b06de64b66 /boot                   xfs     defaults        1 2
UUID=971d09b6-8ce8-49c7-9ec9-16b0155f42cf swap                    swap    defaults        0 0
[root@host-1-105 ~]#

 

2. Understanding the fields.

Partition> Mount Point FS Type Mount Options Backup/Dump FSCK Priority
/dev/mapper/centos_lvm-root / xfs defaults 1 1

 

a. The first column “/dev/mapper/centos_lvm-root” is the disk name/logical volume name/or its UUID which we want to mount.
b. And the second column “/” is the mount point i.e. it is the root filesystem mount point.
c. Third column which reads “xfs” tells us the filesystem type is XFS.
d. Fourth column “defaults” is the mount options which are used while mounting FS.
e. Fifth column “1” is the field that determines if filesystem backup needs to be taken by dump utility or not. 1 means the backup is enabled, and 0 means backup is disabled for this filesystem.

 

3. Understanding the importance of the backup/dump field.
The dump/backup field of /etc/fstab file tells the dump utility that to take this partition/disk/LV backup whenever user instructs it to take backup.

In short, it has no impact on running system, and the backup/dump is not taken automatically.

It is now an obsolete option and not used anymore.

This was earlier designed for ext2/ext3 filesystems only to take backup of these filesystems on tape.

Later we got many utilities like tar, dd, rsync, and this command is no more used in real scenario.

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