Many webmasters ask me how to stop core dump files in Apache.. Now today i will tell you how to stop core dump file in apache.  This is basically happens when System Crashes it makes a coredump file in the public_html Directory.

The possible reason for the core files getting generated is when a php process is killed, apache creates core files under your account .

On phpSuexec servers this may cause due to incorrect php.ini file placed in your account and if it is caused due to php/apache then you can get rid off those core files by editing the httpd startup file on the server end .

Lets start

root@server [~]# vi /etc/init.d/httpd

Search for ulimit lines .For eg : you can see these lines

ulimit -n 1024
ulimit -n 4096
ulimit -n 8192
ulimit -n 16384

You need to add ulimit -c 0 at the end .Which will look like :

ulimit -n 1024
ulimit -n 4096
ulimit -n 8192
ulimit -n 16384
ulimit -c 0

root@server [~]# :wq

Save changes and quit.
Now kill / stop apache service and then start apache service on the server .

root@server [~]# service httpd stop
root@server [~]# service httpd stop
httpd (no pid file) not running
root@server [~]# service httpd startssl
root@server [~]# service httpd startssl
httpd (pid 21154) already running

Finished

It works most of the OS.

Self tested on CENTOS 5.2 i686 on standard

If you want to ssh your vps server or your home computer from your work place (assuming you are using http proxy).You need to use Corkscrew.

corkscrew is a simple tool to tunnel TCP connections through an HTTP proxy supporting the CONNECT method. It reads stdin and writes to stdout during the connection, just like netcat.

It can be used for instance to connect to an SSH server running on a remote 443 port through a strict HTTPS proxy.

Install corkscrew in ubuntu using the following command

sudo aptitude install corkscrew

This will complete the installation.

Configue corkscrew

If your HTTP proxy uses authentication, then you’ll need to tell it about the username and password to use This is where the concept of ‘auth-file’ comes into play. All you have to do is put your username & password, separated by a colon, into a textfile. Once you’ve done this, you just have to tell corkscrew where to find the auth-file. Create a file called .corkscrew-auth in your home directory

$touch .corkscrew-auth

$gedit .corkscrew-auth

and place your username and password in the following format

username:password

Save and exit the file.

Configure ssh For Tunneling

Now we’ll tell ssh what to do when connecting to all or specific hosts. Open up ~/.ssh/config (that’s /home/yourusername/.ssh/config) in your favourite text editor (gedit,nano,vim etc)

$gedit /home/yourusername/.ssh/config

and add the following lines

Host *

ProxyCommand corkscrew proxyhostname proxyport %h %p /home/username/.corkscrew-auth

Save and exit the file

Note: replace proxyhostname and proxyport with the equivalents for your network.

Note: you won’t need to add the last section, ‘/home/username/.corkscrew-auth’, if your HTTP proxy doesn’t use authentication.

What we’ve just told ssh to do is for all hostnames (’Host *’), use the following proxy command to route the connection.If you want more secure connections you can also list of hosts.

Corkscrew Syntax

corkscrew proxy proxyport targethost targetport [ authfile ]

proxy – This is the name of the host running the HTTP proxy.

proxyport – This is the port on which to connect on the proxy.

target – This is the host to reach through the proxy.

targetport – This is the port to connect to on the target host.

Test your SSH connection

ssh serverip

Apt-Cacher-ng is a software package that keeps a cache, on the disk, of Debian/Ubuntu Packages and Release files.When an apt-get like client issues a request for a file, Apt-Cacher intercepts it and if the file is already cached it serves it to the client immediately, otherwise it fetches the file from the Internet, saves it on the cache, and then serves it to the client. This means that several Debian machines can be upgraded but each package need to be downloaded only once.

Apt-Cacher-NG does not require neither an interpreter, nor a web server and not even a huge runtime library. It does never fork after server startup, it does not create flag files, flock() files or similar fun. Instead, it uses native system functions (mmap, sendfile) to operate with few overhead.

Apt-cacher-ng caches the repo’s from the different versions of ubuntu quite nicely. It even nicely supports the different installs of intrepid in my home with different personal package archives (PPA, you know as in ppa.launchpad.net/*).

Install Apt-Cacher-NG in Ubuntu Intrepid

First you need to download the latest version of Apt-Cacher-NG from here or using the following command

wget http://ftp.debian.org/debian/pool/main/a/apt-cacher-ng/apt-cacher-ng_0.3.3-1_i386.deb

Install .deb package using the following command

sudo dpkg -i apt-cacher-ng_0.3.3-1_i386.deb

or you can use the following command to install

sudo apt-get install apt-cacher-ng

Now you need to Add a proxy entry to the apt system

Configure the apt system (apt-get, aptitude, etc.) to use apt-cacher-ng

$ echo ‘Acquire::http { Proxy “http://localhost:3142″; };’ | sudo tee /etc/apt/apt.conf.d/01proxy

Run the following command if you need to disable it

sudo rm /etc/apt/apt.conf.d/01proxy

Add a proxy entry to the Synaptic system for this go to: Settings->Preferences->Network->Manual Proxy Configuration and enter

HTTP Proxy: localhost 3142

FTP Proxy: localhost 3142

Click OK

Click Reload

Dashboard & manual

For apt-cacher-ng dashboard use the following URL

http://localhost:3142/acng-report.html

For apt-cacher-ng manual: (right click &) open with your browser

file:///usr/share/doc/apt-cacher-ng/html/index.html

Import .deb files from the local apt cache

apt-cacher-ng use the .deb files that are already in /var/cache/apt/archives/

sudo mkdir -p /var/cache/apt-cacher-ng/_import

sudo chown apt-cacher-ng /var/cache/apt-cacher-ng/_import

Now open browser using the following URL

http://localhost:3142/acng-report.html

and click “Start Import”

Configure Client Machines

If you want to use apt-cache-ng in ubuntu or debian clients use the following command to use this proxy

$ echo ‘Acquire::http { Proxy “http://serverip:3142″; };’ | sudo tee /etc/apt/apt.conf.d/01proxy