Web Development | Networking | System Administration
Good is not enough if better is possible
Once you server compromised, hacker usually put some backdoor on your server and it might be a tricky process on how to find it. Standard “netstat -anlp” let you see if there’s any unusual listening port on your server. It will display port number, pid, and process name.
Thing is that they usually hiding the process into another regular process name to make it harder to find. Continue reading “Your Server Got Hacked? Get Linux Process Detail Information”
I always have problem when installing cPanel’s Munin through WHM. Solution is quite simple. Just run :
/scripts/checkperlmodules --force
then try re-install it through WHM.
It’s quite easy to change time zone on centos / linux os :
cp /usr/share/zoneinfo/Asia/Jakarta /etc/localtime
Change Asia/Jakarta into your location. After copying, you can run : ntpdate pool.ntp.org
to synchornize your server time with the closest public NTP server.
Yeah, I know core dump files may eat up user’s space quickly. But it is definitely a sign that something wrong with their scripts. So, keeping coredump files is sometimes useful so that we can analyze it properly. Here’s how to analyze core dump files :
strings /home/user/public_html/core.11051|head
You will find what scripts causing the coredump files.
or get a clear view with :
gdb /usr/bin/php /home/user/public_html/core.11051
Hope it can be useful for you!
Just for my own note 🙂
After installing suPHP on server, execute :
find /home/*/public_html -type d -exec chmod 755 {} \;
This command fix all folder permission
find /home/*/public_html -name '*.php' -o -name '*.php[345]' -o -name '*.phtml'| xargs chmod -v 644
This command fix all file permission
#!/bin/bash
cd /var/cpanel/users
for user in *
do
chown -R $user.$user /home/$user/public_html/*
done
This script fix all ownership issue
I got a strange behaviour with Joomla after I apply suhosin and suphp on my cPanel hosting server. When I upload image through Media Manager, suddenly Joomla logged out.
On error_log I see that it has something crashed with flash.
I found a simple solution for this problem. Just disable flash upload on Global Config >> System >> Enable Flash Uploader
The idea of limiting user’s vhost resource usage on Apache brings me to give the suPHP a try. suPHP makes PHP process owned by the owner it self, not “nobody” or apache user, enabling us to limit resource per vhost.
After setting up suPHP with rlimit rule per vhosts, I see that Rlimit really works. Apache kills all PHP execution that hit the Rlimit. So, basically we can have a containers that lock user’s PHP execution, thus preventing user to overload the server with buggy or highload type of PHP script.
But a new problem arised. When PHP execution killed, it generate coredump files. Coredump files are very useful to traceback any crash issues that occur during PHP execution. But I got them all over user’s directory, especially on user’s directory that have a highload type of PHP script. The size may vary from 1MB to 40MB (on my system). They eat up users space every time a greedy resource PHP execution killed. Continue reading “Disable CoreDump on Apache with suPHP”
Installing Munin on a latest Centos 5 via WHM (cPanel) can be very painful (takes a long night googling for me.. lol). On my server (CENTOS Enterprise 5.2 x86_64) – under “Manage Plugin” menu on WHM, it shows : Can’t locate RRDs.pm.
First you have to install rrdtool, rrdtool-devel, and perl-rrdtool. Here’s how to install it (it works for me) :
wget http://dag.wieers.com/rpm/packages/rrdtool/perl-rrdtool-1.2.23-1.el5.rf.x86_64.rpm
wget http://dag.wieers.com/rpm/packages/rrdtool/rrdtool-devel-1.2.23-1.el5.rf.x86_64.rpm
wget http://dag.wieers.com/rpm/packages/rrdtool/rrdtool-1.2.23-1.el5.rf.x86_64.rpm
rpm -ivh rrdtool-1.2.23-1.el5.rf.x86_64.rpm rrdtool-devel-1.2.23-1.el5.rf.x86_64.rpm perl-rrdtool-1.2.23-1.el5.rf.x86_64.rpm
And now you’re ready to install Munin through WHM.
Recently I installed a new server with the latest cPanel release (cPanel 11.23.3-R25623) on Centos 5 64bit version. I notice that under “Tweak Setting” menu on WHM, there are new features that interesting :
Add proxy VirtualHost to httpd.conf to automatically redirect unconfigured cpanel, webmail, webdisk and whm subdomains to the correct port (requires mod_rewrite and mod_proxy)
Automatically create cpanel, webmail, webdisk and whm proxy subdomain DNS entries for new accounts. When this is initially enabled it will add appropriate proxy subdomain DNS entries to all existing accounts. (Use /scripts/proxydomains to reconfigure the DNS entries manually)
When I give a try on those feature, it did work. cPanel become accessible through common http port (80) (instead of port 2082) when we access http://cpanel.domainname.tld. It also work for webmail, WHM, and webdisk.
Meaning we probably dont need a cPanelProxy anymore.
Ok, first of all .. this article originaly posted on netenberg.com, but for me it will be much more easier if I write it my own on my blog.
Centos 5.1 comes with wget version that is not compatible with Fantastico. So you wont be able to install it or upgrade it. Here’s the step that you need to take to remove buggy version of wget and install a “good” one : Continue reading “Installing Fantastico on Centos5.1”
Web Development | Networking | System Administration 