Installing Nginx web-server

Nginx repo

CentOS:
[nginx]
name=nginx repo
baseurl=http://nginx.org/packages/centos/$releasever/$basearch/
gpgcheck=0
enabled=1
RHEL:
[nginx]
name=nginx repo
baseurl=http://nginx.org/packages/rhel/$releasever/$basearch/
gpgcheck=0
enabled=1


manual installation

wget http://nginx.org/download/nginx-1.0.5.tar.gz
tar xvfz nginx-1.0.5.tar.gz
cd nginx-1.0.5
Install nginx
There are lot of options that you can pass to ./configure. To identify list of all the configuration options do the following.
./configure –help


./configure
make
make install

By default, Nginx will be installed in /usr/local/nginx. You may change this and other options with the compile-time options.
During ./configure, you might get the “./configure: error: the HTTP rewrite module requires the PCRE library.” error message about missing PCRE library that is required by nginx http rewrite module.
To solve the problem, either install “pcre” and “pcre-devel” packages on your Linux, or disable
the rewrite module by doing “./configure –without-http_rewrite_module”
/usr/local/nginx/conf/nginx.conf
ls /usr/local/nginx/logs/
access.log
error.log
nginx.pid



Side by Side
In some cases you may need to run both Apache (httpd) and Nginx on port 80. Such a situation can be a server running Cpanel/Whm and as such doesn’t support nginx, so you wouldn’t want to mess with the apache configuration at all.
To do this you have to make sure Apache and Nginx are bound to their own IP adddress, In the event of WHM/Cpanel based webserver, you can Release an IP to be used for Nginx in WHM. At this time I am not aware of a method of reserving an IP, and automatically forcing Apache to listen on a specific set of IPs in a control panel such as DirectAdmin or Plesk. But the link above will show you how with WHM/Cpanel.
Normally Apache will be listening on all interfaces, and such you may see a line like this in your httpd.conf file:
Port 80
#or
Listen 80
Instead you’ll need to tell apache to listen on a specific IP (you can have multiple Listen lines for multiple IPs)
Listen 192.170.2.1:80

Once you have apache configured to listen on a specific set of IPs you can do the same with nginx.
server {
listen 192.170.2.2:80;
...
}
Now that both servers are bound to specific IPs, both can then be started up on port 80. From there you would simply point the IP of the domain to the server you wish to use. In the case of WHM/Cpanel you can either manually configure the DNS entry for the domain going to nginx in WHM, or you can use your own DNS such as with your registrar to point the domain to the specific IP.
Apache behind Nginx
First thing that needs to be done is to change the interface apache listens on:
Listen 127.0.0.1:8080

So that Nginx can listen on port 80
Example of nginx configurations

server {
listen 80;

root /var/www/;
index index.php index.html index.htm;

server_name example.com;

location / {
try_files $uri $uri/ /index.php;
}

location ~ \.php$ {

proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $remote_addr;
proxy_set_header Host $host;
proxy_pass http://127.0.0.1:8080;

}

location ~ /\.ht {
deny all;
}
}

Install / Compile Kernel 3.5

Install / Compile Kernel 3.5
Step 1: Installing Kernel 3.5 Dependencies
Let’s first install dependencies packages gcc, ncurses and then update the system.
# yum install gcc ncurses ncurses-devel

# yum update
Step 2: Downloading Kernel 3.5 Source
# cd /tmp
# wget http://www.kernel.org/pub/linux/kernel/v3.0/linux-3.5.tar.bz2
Step 3: Extracting Kernel 3.5 Source
Once the file is downloaded extract it under /usr/src/ directory by running the below command.
# tar -jxvf linux-3.5.tar.bz2 -C /usr/src/
# cd /usr/src/linux-3.5/
Step 4: Configuring Kernel 3.5 Source
For New Kernel Configuration
Now run the make menuconfig command to configure the Linux kernel. Once you execute the below command a pop up window appears with all the menus. Here you can select your new kernel configuration. If you unfamiliar with these menus, just hit ESC key to exit.
# make menuconfig
Step 5: Compiling Kernel 3.5
Next, type the make command to compile the Kernel 3.5. The compilation would take at least 30-40 minutes depends on your system configuration.
# make
Step 5: Installing Kernel 3.5
Once the compliation completes cleanly, now install the Kernel 3.5 in your Linux system. The below command will create files under /boot directory and also make a new kernel entry in your grub.conf file.
# make modules_install install
Step 6: Verifying Kernel 3.5
To verify newly installed Kernel just type the following command on the terminal.
# uname -r
That’s it. We hope this article will be much helpful to you all. If you’re facing any problems or difficulties while compiling or installing feel free to ask or post your questions using our comment form below.

Linux Directory Structure

Linux filesystem structures and understand the meaning of individual high-level directories.

1. / – Root

Every single file and directory starts from the root directory.
Only root user has write privilege under this directory.
Please note that /root is root user’s home directory, which is not same as /.

2. /bin – User Binaries

Contains binary executables.
Common linux commands you need to use in single-user modes are located under this directory.
Commands used by all the users of the system are located here.
For example: ps, ls, ping, grep, cp.

3. /sbin – System Binaries

Just like /bin, /sbin also contains binary executables.
But, the linux commands located under this directory are used typically by system aministrator, for system maintenance purpose.
For example: iptables, reboot, fdisk, ifconfig, swapon

4. /etc – Configuration Files

Contains configuration files required by all programs.
This also contains startup and shutdown shell scripts used to start/stop individual programs.
For example: /etc/resolv.conf, /etc/logrotate.conf

5. /dev – Device Files

Contains device files.
These include terminal devices, usb, or any device attached to the system.
For example: /dev/tty1, /dev/usbmon0

6. /proc – Process Information

Contains information about system process.
This is a pseudo filesystem contains information about running process. For example: /proc/{pid} directory contains information about the process with that particular pid.
This is a virtual filesystem with text information about system resources. For example: /proc/uptime

7. /var – Variable Files

var stands for variable files.
Content of the files that are expected to grow can be found under this directory.
This includes — system log files (/var/log); packages and database files (/var/lib); emails (/var/mail); print queues (/var/spool); lock files (/var/lock); temp files needed across reboots (/var/tmp);

8. /tmp – Temporary Files

Directory that contains temporary files created by system and users.
Files under this directory are deleted when system is rebooted.

9. /usr – User Programs

Contains binaries, libraries, documentation, and source-code for second level programs.
/usr/bin contains binary files for user programs. If you can’t find a user binary under /bin, look under /usr/bin. For example: at, awk, cc, less, scp
/usr/sbin contains binary files for system administrators. If you can’t find a system binary under /sbin, look under /usr/sbin. For example: atd, cron, sshd, useradd, userdel
/usr/lib contains libraries for /usr/bin and /usr/sbin
/usr/local contains users programs that you install from source. For example, when you install apache from source, it goes under /usr/local/apache2

10. /home – Home Directories

Home directories for all users to store their personal files.
For example: /home/john, /home/nikita

11. /boot – Boot Loader Files

Contains boot loader related files.
Kernel initrd, vmlinux, grub files are located under /boot
For example: initrd.img-2.6.32-24-generic, vmlinuz-2.6.32-24-generic

12. /lib – System Libraries

Contains library files that supports the binaries located under /bin and /sbin
Library filenames are either ld* or lib*.so.*
For example: ld-2.11.1.so, libncurses.so.5.7

13. /opt – Optional add-on Applications

opt stands for optional.
Contains add-on applications from individual vendors.
add-on applications should be installed under either /opt/ or /opt/ sub-directory.

14. /mnt – Mount Directory

Temporary mount directory where sysadmins can mount filesystems.

15. /media – Removable Media Devices

Temporary mount directory for removable devices.
For examples, /media/cdrom for CD-ROM; /media/floppy for floppy drives; /media/cdrecorder for CD writer

16. /srv – Service Data

srv stands for service.
Contains server specific services related data.
For example, /srv/cvs contains CVS related data.