The document presents essential information about Linux system administration, focusing on the superuser 'root', disk partitions, and filesystem management. It outlines how to create, mount, and manage filesystems and partitions, as well as the purpose of the /etc/fstab file for configuration. Key filesystem types and their attributes are also discussed to enhance understanding of Linux storage management.

1. EssEntial nEEds of
administration
PrEsEntEd to:- mr. Purushottam das
PrEsEntEd By:- PaPu Kumar
sEction:- B
roll no.:- 2061424(47)
sEmEstEr:- iii

2. TOPICS
 The Superuser: Root
 Disks and Partitions
 Making New Partitions
 Mounting Filesystems
 Mounting a Filesystem: mount
 Mounting Other Filesystems
 Unmounting a Filesystem: umount
 Sample /etc/fstab
 Filesystem Types

3. The Superuser: Root
 Every Linux system has a user called ‘root’
 The root user is all-powerful
 Can access any files
 The root user account should only be used for system administration, such as installing
 software
 When logged in as root, the shell prompt usually ends in #
 Usually best to use su for working as root:
 $ whoami
 fred
 $ su -
 Password:
 # whoami
 root

4. Concepts: Disks and Partitions
 A hard disk provides a single large storage space
 Usually split into partitions
 Information about partitions is stored in the partition table
 Linux defaults to using partition tables compatible with Microsoft Windows
 For compatibility with Windows, at most four primary partitions can be made
 But they can be extended partitions, which can themselves be split into
smaller logical partitions
 Extended partitions have their own partition table to store information about
logical
 partitions

5. Making New Partitions
 Create new partitions with the n command
 Choose whether to make a primary, extended or logical partition
 Choose which number to assign it
 fdisk asks where to put the start and end of the partition
 The default values make the partition as big as possible
 The desired size can be specified in megabytes, e.g., +250M
 Changes to the partition table are only written when the w command is
given

6. Filesystems
 Some confusion surrounds the use of the term ‘filesystem’
 Commonly used to refer to two distinct concepts
 1. The hierarchy of directories and files which humans use
to organise data on a system
 (‘unified filesystem’)
 2. The formatting system which the kernel uses to store
blocks of data on physical media
 such as disks (‘filesystem types’)

7. Disk Naming
 The device files for IDE hard drives are /dev/hda to /dev/hdd
 hda and hdb are the drives on the first IDE channel, hdc and hdd the ones
on the second channel
 The first drive on each channel is the IDE ‘master’, and the second is the
IDE ‘slave’
 Primary partitions are numbered from 1–4
 Logical partitions are numbered from 5
 The devices /dev/hda, etc., refer to whole hard disks, not partitions
 Add the partition number to refer to a specific partition

8. Changing Partition Types
 Each partition has a type code, which is a number
 The fdisk command shows a list of known types
 The command t changes the type of an existing Partition
 Enter the type code at the prompt
 Linux partitions are usually of type ‘Linux native’ (type 83)
 Other operating systems might use other types of partition,
many of which can be understood by Linux

9. Mounting Other Filesystems
 mount /dev/sdb3 /mnt/extra mounts the filesystem stored in
the /dev/sdb3 device on the
 mount point /mnt/extra
 You may occasionally need to specify the filesystem type
explicitly:
 # mount -t vfat /dev/hdd1 /mnt/windows
 Allowable filesystem types are listed in the mount(8)
manpage
 To see a list of the filesystems currently mounted, run mount
without any options

10. Configuring mount: /etc/fstab
 The /etc/fstab file contains information about filesystems
that are known to the system administrator
 Specifying a filesystem in /etc/fstab makes it possible to use
its mount point as the only argument to mount
 /etc/fstab also configures which filesystems should be
mounted at boot-up
 Each line in /etc/fstab describes one filesystem
 Six columns on each line

11. Sample /etc/fstab
 A sample /etc/fstab file:
 # device mount-point type options (dump) pass-
no
 /dev/hda3 / ext2 defaults 1 1
 /dev/hda1 / boot ext2 defaults 1 2
 /dev/hda5 / usr ext2 defaults 1 2
 /dev/hdb1 / usr/local ext2 defaults 1 2
 /dev/hdb2 / home ext2 defaults 1 2
 none / proc proc defaults 0 0
 /dev/scd0 / mnt/cdrom iso9660 noauto, users, 0 0
 /dev/fd0 /mnt/floppy auto noauto, users 0 0

12. Filesystem Types
 The most common filesystem types are:
 ext2 The standard Linux filesystem
 iso9660 The filesystem used on CD-ROMs
 proc Not a real filesystem, so uses none as the device. Used as a way
 for the kernel to report system information to user processes vfat The
filesystem used by Windows 95
 auto Not a real filesystem type. Used as a way of asking the mount
 Networked filesystems include nfs (Unix-specific) and smbfs (Windows
or Samba)
 Other, less common types exist; see mount(8)

13. THANK U