Free Antivirus Software - 2017

1.       Bitdefender Antivirus Free Edition

2.       Avira Antivirus

3.       Avast Free Antivirus

4.       AVG Free Antivirus

5.       Kaspersky Lab Internet Security 2017

6.       Sophos Home Free Antivirus

7.       Panda Free Antivirus

8.       Comodo Antivirus

9.       Check Point ZoneAlarm Free Antivirus + Firewall

10.   Microsoft Windows Defender

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UEFI vs. traditional BIOS firmware

UEFI: Unified Extensible Firmware Interface

BIOS: Basic Input/output System

The advantages of UEFI

·         A powerful pre-boot environment capable of running applications

·         Modular design

·         CPU-independent architecture (Itanium, x86, x86-64, ARM Arch32, Arm Arch64)

·         BIOS interface compatibility and legacy booting

·         The ability to boot from disks larger than 2TiB (note the difference between 2TB and 2TiB)

MBR: Master Boot Record

GPT: GUID Partition Table

ESP: EFI System Partition

The legacy BIOS systems are only able to boot from MBR partition tables (there are exceptions, but this is generally a rule) and the MBR specification can only address up to 2TiB of disk space, which results in a BIOS system only being able to boot from disks of 2TiB or smaller.

Other disadvantages of MBR formatted disks include a limited number of bootable partitions and a single pointer to a bootloader/boot manager.

The GPT specification allowed the disks of significantly larger size (several orders of magnitude, up to Zettabytes in size) due to its larger bit allotment for partition addressing, 64B instead of the 16B used by MBR. GPT can partition disks of varying sizes depending on the sector size. This is due GPT addressing sectors as opposed to individual bits or bytes.

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We have C Drive on Computer. But we don’t have A & B WHY?

Because the initial state of the computer we had two difference small size capacity of floppy disk 5.25inch [1.2MB] and 3.5 inch [1.44MB]. We named those are A and B. Then we got permanent default high capacity drive. We named that as C Drive.

Floppy Disk Storage:

Invention in 1967.

After 1980 we avoided to use floppy disks. 

Types of drives include

·         1.44 MB 3.5 inch drive

·         2.88 MB 3.5 inch drive

·         720KB 3.5 inch drive

·         1.2 MB 5.25 inch drive

·         360KB 5.25 inch drive

·         80KB 8 inch drive

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3com Switch Initial Configuration

3com Switch Configuration :

step 1 : system-view (change user mode)

step 2 : sysname deptname-4210 (give the name for the switch)

step 3 : interface vlan-interface 1 (add ip to the switch)

ip   address    192.168.1.63    255.255.255.0

step 4 :  quit

step 5 :  display   brief   interfaces

interface  ethernet  1/0/1

port    access   vlan    1113

step 6 : interface fastethernet     1/0/25  ( we need consider 25,26,27,28)

port     link-type     trunk

port    trunk     permit    vlan    1113

port    trunk     permit    vlan    1213

port    trunk     permit    vlan    1301

undo shutdown

discrption uplinkport

step 7 : local-user admin

password cisco

save

step 8 : display   brief   interfaces

system-view

display version

display   currentconfiguration

display   savedconfiguration

display     interface     vlan-interface    1

display   ip   interface   brief

display   brief   interfaces

display    vlan

display    vlan    1113

display   vlan    all

display    interface    g1/0/6

interface fastethernet     1/0/25

interface    g1/0/6

port     link-type     trunk

port    trunk     permit    vlan    1100    1220

undo shutdown

system-view

display   brief   interfaces

interface  ethernet  1/0/13

port    access   vlan    1301                            (voice vlan)

display   brief   interfaces

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Linux Partition Sizes

A swap partition (2048)

A /boot partition (200)

A / partition
A /var/log partition (2048)
A /var/www partition (2048)

A /boot/ partition (250 MB) A swap partition (at least 256 MB) Root and /root

A root partition (3.0 GB - 5.0 GB)

Swap partitions are used to support virtual memory. In other words, data is written to a swap partition when there is not enough RAM to store the data your system is processing.

4GB of RAM or less................ a minimum of 2GB of swap space

4GB to 16GB of RAM.............. a minimum of 4GB of swap space

16GB to 64GB of RAM.............a minimum of 8GB of swap space

64GB to 256GB of RAM.......... a minimum of 16GB of swap space

256GB to 512GB of RAM........ a minimum of 32GB of swap space

A /boot/ partition (250 MB)

The partition mounted on /boot/ contains the operating system kernel (which allows your system to boot Fedora), along with files used during the bootstrap process. For most users, a 250 MB boot partition is sufficient.

A root partition (3.0 GB - 5.0 GB)

This is where "/" (the root directory) is located. In this setup, all files (except those stored in /boot) are on the root partition.

A 3.0 GB partition allows you to install a minimal installation, while a 5.0 GB root partition lets you perform a full installation, choosing all package groups.

/............... 250 MB

/usr......... 250 MB, but avoid placing this on a separate partition

/tmp........ 50 MB

/var......... 384 MB

/home..... 100 MB

/boot....... 250 MB

The /var directory holds content for a number of applications, including the Apache web server. It also is used to store downloaded update packages on a temporary basis. Ensure that the partition containing the /var directory has enough space to download pending updates and hold your other content.

The /usr directory holds the majority of software content on a Fedora system. For an installation of the default set of software, allocate at least 4 GB of space. If you are a software developer or plan to use your Fedora system to learn software development skills, you may want to at least double this allocation.

The / (or root) partition is the top of the directory structure. The /root directory (sometimes pronounced "slash-root") directory is the home directory of the user account for system administration.

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File System Types

Fedora allows you to create different partition types, based on the file system they will use. The following is a brief description of the different file systems available, and how they can be utilized.

Btrfs — Btrfs is under development as a file system capable of addressing and managing more files, larger files, and larger volumes than the ext2, ext3, and ext4 file systems. Btrfs is designed to make the file system tolerant of errors, and to facilitate the detection and repair of errors when they occur. It uses checksums to ensure the validity of data and metadata, and maintains snapshots of the file system that can be used for backup or repair.

Because Btrfs is still experimental and under development, the installation program does not offer it by default. If you want to create a Btrfs partition on a drive, you must commence the installation process with the boot optionbtrfs.

Btrfs is still experimental

Fedora 13 includes Btrfs as a technology preview to allow you to experiment with this file system. You should not choose Btrfs for partitions that will contain valuable data or that are essential for the operation of important systems.

ext2 — An ext2 file system supports standard Unix file types (regular files, directories, symbolic links, etc). It provides the ability to assign long file names, up to 255 characters.

ext3 — The ext3 file system is based on the ext2 file system and has one main advantage — journaling. Using a journaling file system reduces time spent recovering a file system after a crash as there is no need to fsck the file system.

ext4 — The ext4 file system is based on the ext3 file system and features a number of improvements. These include support for larger file systems and larger files, faster and more efficient allocation of disk space, no limit on the number of subdirectories within a directory, faster file system checking, and more robust journalling. The ext4 file system is selected by default and is highly recommended.

physical volume (LVM) — Creating one or more physical volume (LVM) partitions allows you to create an LVM logical volume. LVM can improve performance when using physical disks.

software RAID — Creating two or more software RAID partitions allows you to create a RAID device.

swap — Swap partitions are used to support virtual memory. In other words, data is written to a swap partition when there is not enough RAM to store the data your system is processing.

vfat — The VFAT file system is a Linux file system that is compatible with Microsoft Windows long filenames on the FAT file system. This file system must be used for the /boot/efi/ partition on Itanium systems.

xfs — XFS is a highly scalable, high-performance file system that supports filesystems up to 16 exabytes (approximately 16 million terabytes), files up to 8 exabytes (approximately 8 million terabytes) and directory structures containing tens of millions of entries. XFS supports metadata journaling, which facilitates quicker crash recovery. The XFS file system can also be defragmented and resized while mounted and active.

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About YUM(Yellodog Updater, Modified)

Yellowdog Updater, Modified (yum)

RPM (RedHat Package Manager)

GPL (General Public License)

1. Install a Package with YUM

# yum install firefox

# yum -y remove firefox

2. Removing a Package with YUM

# yum remove firefox

3. Updating a Package using YUM

# yum update mysql

4. List all Available Packages using YUM

# yum list | less

5. Yum Provides Function

# yum provides /etc/httpd/conf/httpd.conf

6. Check for Available Updates using Yum

# yum check-update

7. Update System using Yum

# yum update

8. List all available Group Packages

# yum grouplist

9. Install a Group Packages

# yum groupinstall 'MySQL Database'

10. Update a Group Packages

# yum groupupdate 'DNS Name Server'

11. Remove a Group Packages

# yum groupremove 'DNS Name Server'

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