what is disk formatting.

Formatting is nothing but an arranging file system to organizing data base in storage devices, Such as Hard disk, DVD, etc.

Each and every operating system will have standard file system.

Windows - fat32, Ntfs

Linux - ext2, ext3 & ext4

Solaris - ufs

what is disk partitioning in linux.

Partitioning is an electronic process of dividing Physical Hard disk space into group of drives / volumes.

There are 3 types of partitions:

Primary Partitions: It is required to install the Operating system. We can create up to 4 Primary Partitions.

Extended Partition: Extended Partition is the space for creating logical partitions.

No drive letter assigned for Extended Partitions, we can create only one extended partition.

Logical Partition: Logical Partitions can be created from Extended Partitions space.

*We can create up to 63 logical partitions in Red Hat Linux operating system.

what is swap space in linux.

 Swap is a file system in Linux, when RAM is full system needs more memory resources,

During such instances, what is the Inactive process in memory uses the swap area temporarily. Its works as Virtual Memory.

user administration in linux

USER: User is an account, which is used for to run the system.

Types of users:

System Users: Who can control and configure the system services, These users create automatically by the operating system.

Normal Users: Who can access the system resources? These users are being managed by super-user.

Group: Collection of users called as a Group.

Each USER and GROUP has a Unique Numerical Identification Number called a UID & GID

• These ID’s Starting from 0 to 499 will refers as System Users.

• These ID’s starting from 500 to 60,000 will refer as Normal Users.

• Red hat Enterprise Linux follows UPG Scheme (User Private Group), that mean whenever a user created by default with the same name a unique group also created.

NOTE: I will explain practical in next post.

advanced file permissions in linux

There are 3 advance file permissions available in Linux:

1) SUID 

2) SGID

3) STIKIBIT.

Set-user-ID: It provides administrator privileges to normal users to run administration commands.

Set-group-ID: It provides Group ID - Hierarchy on executable command.

Stick Bit: It restricts others to removing the data on the Stick-bit applied recourse expect owner.

NOTE: I will explain practical in next post.

basic file permissions in linux

•   Permissions are a type of access control to users and groups on system resources.

• We have three methods of basic permissions such as “Read, Write and Execute.”

• These permissions can be assigned at three levels such as Owner, Group and Others.

Read: To view content of files / view list of data in directories.

Write: To write content of files / create data under directories.

Execute: To run binaries files / commands.

UMASK

UMASK stands for “User file creation mask” that controls the system file permissions.

The default file permissions are assigned by the system whenever you create any object, those default permissions values are based on UMASK value of the user.

• Default UMASK value for Super user is 022

• Default UMASK value for Normal user is 002.

DISK QUOTA

Quota is a Mechanism, which is used to restrict USERS to usage of Hard disk space, So that we can provide disk usage limitation to users & groups.

ACL

ACL - Access control list, we can provide different file permissions to individual users and groups on files.

SUDO

SUDO allows users to run another user’s programs with the security privileges. (Normally - super-user or root)

NOTE: I will explain practical in next post.

file system hierarchy in linux

•   Any operating system organizes the Information in the formation of files in an order.

• This hierarchical organization of files system is called “File System Hierarchy”

• Linux fallows stranded File System Hierarchy:

/ :This is the Top level directory of Linux File system.

/boot : It contains all boots related Information such as boot-loader, vmlinuz & initrtd.

/root : Root is the Administrator of Linux. This is default home directory of root user.

/home :This is the default home directory of all normal users.

/bin : It contains Binary file (commands) used by super user and normal users.

/sbin :Super user Binary- It contains all administration commands.

/etc :It contains all the configuration files of system and network services.

/usr :Unix System Resources- It contains programs and applications information.

/var :Variable- It contains variable information such as system log files.

/dev : Devices- It contains all devices information, such as Hard-drive, DVD etc..

/opt : Optional- It contains the Third Party applications information.

/lib :Library- It contains library files which are needed by applications & programs.

/proc :Processes- It contains currently running process Information of system.

/media:It contains Mount Points of Removable media such as DVD, Flash Drive etc.

/tmp :Temporary- It contains temporary files used by the system.