Installing SVN (Subversio)

Here are the steps to install SVN :

==================================
cd /usr/local/src/

wget http://subversion.tigris.org/downloa...n-1.4.5.tar.gz
wget http://subversion.tigris.org/downloa...s-1.4.5.tar.gz
wget http://www.sqlite.org/sqlite-3.5.2.tar.gz

tar xzf subversion-1.4.5.tar.gz
tar xzf subversion-deps-1.4.5.tar.gz
tar xzf sqlite-3.5.2.tar.gz

cd sqlite-3.5.2
./configure
make
make install
./sqlite3
.help
.exit
cd ..

cd subversion-1.4.5
./configure
make
make install
svn --version
===============================

Tomcat version

In order to check the Tomcat version :

/usr/local/jakarta/tomcat/bin/version.sh

Invalid License File error

When you login to cpanel/whm when you are getting this error :

Invalid License File error

In order to fix the issue you login to
Server run the script :
=============
/usr/local/cpanel/cpkeyclt
==============

Databases showing Zero MB size in cPanel

To fix the issue.
Edit the file /var/cpanel/cpanel.config

disk_usage_include_sqldbs=1 ( you need to set it to '1' if '0' )

Then ,

/scripts/update_db_cache

Linux - Boot Process

Boot sequence summary
It can classified into :

• BIOS
• Master Boot Record (MBR)
• LILO or GRUB
• Kernel
• init
• Run Levels

BIOS
The Basic Input/Output System is the lowest level interface between the computer and peripherals. and The BIOS is a program stored in Read Only Memory (ROM) .
The BIOS performs integrity checks on memory and seeks instructions on the Master Boor Record (MBR) on the floppy drive or hard drive.
BIOS then does the Power On Self Test, or POST routine runs to find certain hardware and to test that the hardware is working at a basic level. It compares the hardware settings in the CMOS (Complementary Metal Oxide Semiconductor) to what is physically on the system. It then initialize the hardware devices.

Once the POST is completed, the hardware jumps to a specific, predefined location in RAM.

BIOS Loads 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 bootup. The exact key depends varies, but is often one of Del, F1, F2, or F10.

MASTER BOOT RECORDER (MBR)
The MBR points to the boot loader (GRUB or LILO: Linux boot loader).
Standard DOS MBR will:

• look for a primary partition (/dev/hda1-4) marked bootable
• load and execute first 512 bytes of this partition

LILO
LILO (LInux LOader) is a generic boot loader for Linux.

• does not understand filesystems
• code and kernel image to be loaded is stored as raw disk offsets
• uses the BIOS routines to load

Reconfiguring LILO

One minute guide to installing a new kernel

• copy kernel image (bzImage) and modules to /boot and /lib/modules
• edit /etc/lilo.conf
  • duplicate image= section, eg:

    
         image=/bzImage-2.4.14
    
           label=14
    
           read-only
    

  • man lilo.conf for details
• run /sbin/lilo
• reboot to test

GRUB

Understands file systems

config lives in /boot/grub/menu.lst or /boot/grub/grub.conf

Boot Loader will then ask for the OS label which will identify which kernel to run and where it is located
Depending on the kernel boot option chosen or set as default, lilo or grub will load that kernel

KERNEL

• initialise devices .It initializes virtual devices related to the file system, such as LVM or software RAID .
• Then optionally loads initrd. Init is the root/parent of all processes executing on Linux.
  

• runs /sbin/init which is process number 1 (PID=1).

/sbin/init :

• reads /etc/inittab (see man inittab which specifies the scripts below
  • Run boot scripts:
    • debian: run /etc/init.d/rcS which runs:
      • /etc/rcS.d/S* scripts
      • /etc/rc.boot/* (depreciated)
    • redhat: /etc/rc.d/rc.sysinit script which: loads modules, check root FS and mount RW, mount local FS, setup network, and mount remote FS
  • switches to default runlevel eg 3.
    • run scripts /etc/rc3.d/S*
    • run programs specified in /etc/inittab

Run Levels

• 0 halt
• 1 single user
• 2-4 user defined
• 5 X11 only (0 or 1 text console)
• 6 Reboot
• Default is defined in /etc/inittab, eg:
  • id:3:initdefault: