List for requests for comments rfc

Requests for Comments (RFC)

List for Requests for Comments RFC Requests for Comments (RFC) RFC: Requests for Comments -RFCs is an ongoing set of documents issued by the Internet Engineering Task Force -IETF at the Network Information Center -NIC that presents new protocols and establishes standards for the Internet protocol suite. Each such document defines an aspect  ..

Deny ssh access for root user

Disabling ssh access for root and allowing su

Disabling ssh access for root and allowing "su" The following are the steps to disable root and enable "su" over SSH step : 1 create a user make him a member of wheel group.(use cpanel and WHM or manually using shell) step : 2 uncomment the following line in the file /etc/pam.d/su auth required  ..

Redhat sysreport backup tool

Linux system recovery

First step towards system backup and recovery. Sysreport is a simple tool that will backup all the critical files of a linux box. Just run the command "sysreport" and it will backup all the critical files of the server and create a compressed tar file in the name of the server and  ..

Create file with date timestamp

Copy or rename a file with date time stamp

Creating file with date time stamp Many times you may need to need to create a file file with date and time stamp. It will be much helpful for the administrator when they have a copy of configuration or other files with date and time timestamp. Command to create a file with  ..

How does a system boot

Boot process Machine or Computer

Boot Process of a Linux Machine BOOTING PROCESS BIOS BootSector KernelInitilisation Init SysVinit scripts. BIOS(Basic Input Output System) Bios is a piece of software that is built-in to the machine,usually by being stored in the flash ROM on the motherboard. There are two purpose of BIOS,one it takes the machine from a power-on state  ..

Kernel recompilation steps

How to do kernel Compilation

Kernel Kernel Recompilation Steps 1. Download the latest kenel from www.kernel.org to /usr/src 2. Unpack the tar ball # tar -zxvf linux-x.x.x.tar.gz # cd linux-x.x 3. backup the .config file from /boot 4. Run the command make mrproper to remove the config file # make mrproper this removes the current .config and other files 5. Now lets start for kernel  ..

Booting process of linux os

How does my system boots up

BOOTING PROCESS: BIOS BootSector KernelInitilisation Init SysVinit scripts. BIOS(Basic Input Output System) Bios is a piece of software that is built-in to the machine,usually by being stored in the flash ROM on the motherboard. There are two purpose of BIOS,one it takes the machine from a power-on state to the point where it  ..

Different run levels

Runlevels in Linux

Runlevels in Linux Linux operates in runlevel 3 - full multi-user mode. The following runlevels are defined in Red Hat Linux: 0 - Halt 1 - Single-user mode 2 - Not used (user-definable)   ..

How to change default gateway

Changing Gateway IP Address

How to change default gateway Server needs to have a single default gateway. DHCP servers will automatically assign a default gateway to DHCP configured NICs, but NICs with configured static IP addresses will need to have a manually configured default gateway. This can be done with a simple command. This example  ..

How to recover deleted files

Linux or UNIX Recover deleted files - undelete files

Linux or UNIX Recover deleted files - undelete files If you run rm command accidentally and deleted important a file, recovery becomes critical under Linux and/or UNIX oses. Since Linux is multiuser and multitasking operating system other users/process can overwrite deleted file disk space. So you need to take down system to  ..

Boot sequence in linux

Linux Booting Steps

Boot Sequence In Linux Boot Process 1) BIOS 2) Master Boot Record (MBR) 3) LILO or GRUB 4) Kernel 5) init 6) Run Levels 1) BIOS Load boot sector from one of: Floppy CDROM Hard drive The boot order can be changed from within the BIOS. BIOS setup can be entered by pressing a key during boot up. The exact key depends varies,  ..

What is gui

GUI in Linux - startx

What is GUI Computer systems that support two or more simultaneous users. All mainframes and minicomputers are multi-user systems, but most personal computers and workstations are not. Another term for multi-user is time sharing.   ..

What is shell in linux

Define Shell

What is shell in linux A shell is a program that provides the traditional, text-only user interface for Unix-like operating systems. Its primary function is to read commands that are typed into a console (i.e., an all-text display mode) or terminal window (an all-text window) in a GUI (graphical user interface)  ..

What is lilo

Last in last out

What is lilo Lilo means last in last out . LILO is a versatile boot loader for Linux. It does not depend on a specific file system, can boot Linux kernel images from floppy disks and hard disks, and can even boot other operating systems. One of up to sixteen differernt  ..

How to check and repair a linux file system

What is FSCK

What is FSCK fsck - check and repair a Linux file system. fsck is used to check and optionally repair one or more Linux file systems. filesys can be a device name (e.g. /dev/hdc1, /dev/sdb2), a mount point (e.g. /, /usr, /home), or an ext2 label or UUID specifier (e.g.UUID=8868abf6-88c5-4a83-98b8-bfc24057f7bd or LABEL=root).  ..