1. The cPanel developers indicated that DKIM auth will be a feature in 11.32, therefore, when 11.32 is released it’s possible that a few steps in this guide will become obsolete
2. cPanel does not recommend or provide support for some of the changes this tutorial will ask you to make.  As usual, make these changes at your own risk or use our server consultation services for help

Upgrade Exim

DKIM is supported in Exim 4.70 and higher – the version current at the time this article was written is 4.69. Therefore, you will need to upgrade.  Hop over to the below URL, locate the latest version of Exim 4.7x, and navigate to the folder that corresponds with your operating system to find the RPM:

http://httpupdate.cpanel.net/exim/

In this case, we downloaded the RPM from:

http://httpupdate.cpanel.net/exim/4.70-4/centos/5.6/exim-4.70-4_cpanel_maildir.i386.rpm

On your server, run the following command (replace the URL with the one corresponding to the RPM you found)

rpm -Uvh http://httpupdate.cpanel.net/exim/4.70-4/centos/5.6/exim-4.70-4_cpanel_maildir.i386.rpm --nodeps

Now, verify the version:

root@server [~]# rpm -qa |grep -i exim
exim-4.70-4_cpanel_maildir

You’ll also want to keep cPanel from running an Exim update and reverting the version back to 4.69:

touch /etc/eximupdisable

 

If you have existing domains on this server, make sure to move local and remote domains files back:

mv -f /etc/localdomains.rpmsave /etc/localdomains
mv -f /etc/remotedomains.rpmsave /etc/remotedomains

*If you have trouble installing the RPM due to fetchmail or a conflict with the previously-install Exim package, do

yum remove fetchmail

rpm -e exim-4.69-29_cpanel_maildir (replace with the actual name of the old Exim package)

Install DomainKeys

The topic of how to install DomainKeys was previously covered in this article. Install the keys for each user, or run a loop as shown in the article to install them for all users.  The keys will be in: /var/cpanel/domain_keys/[public|private]/$domain .

Configure Exim

Open /etc/exim.conf and near the top, add the following lines:

DKIM_DOMAIN = ${lc:${domain:$h_from:}}
DKIM_FILE = /var/cpanel/domain_keys/private/${lc:${domain:$h_from:}}
DKIM_PRIVATE_KEY = ${if exists{DKIM_FILE}{DKIM_FILE}{0}}

Then scroll down until you see these lines:

remote_smtp:
driver = smtp

Replace this with:

remote_smtp:
driver = smtp
dkim_domain = DKIM_DOMAIN
dkim_selector = default
dkim_private_key = DKIM_PRIVATE_KEY
dkim_canon = relaxed
dkim_strict = 0

Now, restart Exim:

service exim restart

The additions to exim.conf will use a domain’s key, if the domain has one, to sign each message with DKIM.

Now, keep in mind that cPanel will overwrite these changes during cPanel updates. You have the following options:

• Run chattr +ia /etc/exim.conf, OR:
• Copy /etc/exim.conf to /root/exim.conf and create a file called /scripts/posteximup (and chmod to 700) containing the following code:

scp -p /root/exim.conf /etc/exim.conf
service exim restart

Verify

The easiest way to verify the functionality of your new DKIM setup is to send an email from your server to check-auth@verifier.port25.com . You’ll get an autoresponse back letting you now that everything is working (note that with DKIM, DomainKeys are obsolete so a status of “neutral” is normal)

SPF check:          pass
DomainKeys check:   neutral
DKIM check:         pass
Sender-ID check:    pass
SpamAssassin check: ham

Related posts:

1. Copy Outgoing Email on a cPanel Server with Exim
2. Installing DomainKeys and SPF Records
3. Changing Exim’s Sending IP

Sorry for the inconvience!
The filesystem mounted at / on this server is running out of disk space. cPanel operation has been temporarily suspended to prevent something bad from happening. Please ask your system admin to remove any files not in use on that partition

While 99% may seem like a dangerous limit, servers nowadays are getting rather large. If you have a server with over 3T of disk space, that 1% free could be well over 100G of space – space that would seemingly become waste.

Until this limit is removed in a future release, you can actually trick cPanel into thinking that the server has more space available. The key is the cache files located in /root/.cpanel/datastore, specifically the file _bin_df_-P_-k_-l.

If you edit that file and change the occurrence of 99% to a lower value, you’ll see the restricted cPanel and WHM features return to normal.  Keep in mind that the cache regenerates, so in some cases it may be appropriate to create a cron job to periodically change the file.

Of course, if 99% disk usage on your server leaves you with a minuscule amount of space, you’ll want to remove some files or add additional storage. The following articles may be useful:

• http://www.thecpaneladmin.com/11-ways-to-free-up-disk-space-on-a-cpanel-server/
• http://www.thecpaneladmin.com/huge-cpan-folder-home/
• http://www.thecpaneladmin.com/managing-multiple-hard-drives-cpanel/
• http://www.thecpaneladmin.com/manually-rearranging-accounts/

Thanks to my colleague Lee for sharing this tidbit of info

Related posts:

1. 11 Ways to Free Up Disk Space on a cPanel Server
2. Disk Space for MySQL Databases in cPanel Show as 0MB
3. Resolving Domain Park Wrapper Errors

You can, however, easily compile your own RPM and manually upgrade OpenSSH.  The commands below are the ones I used to install version 5.8 (the latest stable at the time of this post), but can essentially be used for any compatible version.

First, download the OpenSSH source tarball from the vendor and unpack it. You can find the tarballs at http://www.openssh.com/portable.html

wget http://mirror.mcs.anl.gov/openssh/portable/openssh-5.8p1.tar.gz

tar -xvzf openssh-5.8p1.tar.gz

Copy the spec file and tarball:

cp ./openssh-5.8p1/contrib/redhat/openssh.spec /usr/src/redhat/SPECS/

cp openssh-5.8p1.tar.gz /usr/src/redhat/SOURCES/

Do a little magic:

cd /usr/src/redhat/SPECS

perl -i.bak -pe ‘s/^(%define no_(gnome|x11)_askpass)\s+0$/$1 1/’ openssh.spec

…and build your RPM:

rpmbuild -bb openssh.spec

Now if you go back into /usr/src/redhat/RPMS/<arch> , you should see three RPMs. Go ahead and install them:

rpm -Uvh *.rpm

To verify the installed version, just type ‘ssh -v localhost’ and you should see the banner come up, indicating the new version.

Related posts:

1. cPanel Updates on Redhat 9 Can Break Stuff
2. Manually Upgrading MySQL
3. Upgrading or Downgrading MySQL

First, go to WHM > Exim Configuration Editor, then click “Advanced Editor” at the bottom. Don’t make any changes, just click “save”. This should create a file on the server called /etc/exim.conf.local.  From command line as root, you’ll need to edit /etc/exim.conf.local and add some options to the @CONFIG@ and @TRANSPORTSTART@ sections. The end result would look like this (plus any edits you may have already made):


@AUTH@

@BEGINACL@

@CONFIG@
system_filter_directory_transport = local_copy_outgoing

@DIRECTOREND@

@DIRECTORMIDDLE@

@DIRECTORSTART@

@ENDACL@

@RETRYEND@

@RETRYSTART@

@REWRITE@

@ROUTEREND@

@ROUTERSTART@

@TRANSPORTEND@

@TRANSPORTMIDDLE@

@TRANSPORTSTART@
local_copy_outgoing:
driver = appendfile
delivery_date_add
envelope_to_add
return_path_add
group = cpaneleximfilter
user = cpaneleximfilter
mode = 0660
maildir_format = true
create_directory = true

Now, make a copy of the existing system filter file to a custom location, so cPanel updates don’t mess with it:

cp  /etc/cpanel_exim_system_filter /etc/cpanel_exim_system_filter_custom

Edit /etc/exim.conf.localops and change the “systemfilter” option to match our new file:

systemfilter=/etc/cpanel_exim_system_filter_custom

Now, open /etc/cpanel_exim_system_filter_custom and add the following block of code to the end of the file:

if $header_from: contains "@senderdomain.com"
then
unseen deliver "other@emailaddress"
endif

Replace the blue text with the sender domain (or email address)  and the email address that outgoing mail should be copied to.

Apply these new settings to the exim.conf and restart:

/scripts/buildeximconf
service exim restart

Now when you send email from the email address or domain specified in the filter file, it will be copied to the other email address.

Related posts:

1. Using Custom RBL’s with Exim and cPanel
2. Changing Exim’s Sending IP
3. 10 Tips for Improving Email Delivery

First thing, try running

/scripts/fixquotas

This’ll take a while depending on your current disk usage, but will usually fix the problem. If it doesn’t, make sure that quotas are on for your filesystem.  Look at /etc/fstab, and in the fourth column (the options column), make sure that ‘usrquota’ is specified for the file system that contains your user home folders.  For example, this is how ours looks:

LABEL=/     /           ext3    defaults,noatime,usrquota 0  0
LABEL=/home    /home          ext3    defaults,noatime,usrquota 0  0

If /home is part of the / partition, then the quotas need to be applied to / .

Now, remount the partitions with new options.  For the root ( / ) partition for example, you’d run the following command:

mount -o remount /

Then run the following command to update quotas:

/scripts/initquotas

If the problem indicates a problem writing to /aquota.user or similar, make sure the file isn’t set to immutable:

chattr -ia /aquota.user

After following these steps, if you’re still having a problem feel free to submit a support ticket and we’ll help you out!

Related posts:

1. Performance Tip: Disable Optimizefs
2. Managing Multiple Hard Drives with cPanel
3. 11 Ways to Free Up Disk Space on a cPanel Server

History

The first cron was written in the early 1970s for Version 7 UNIX as a system service (also known in UNIX as a daemon). The algorithm, invoked from the /etc/inittab location whenever the OS entered a multi-user mode, was simple — every minute, it checked a directory for any files set to be run at the current date/time, and ran any it found under superuser root. The next version of cron, created for the release of UNIX System V, extended capabilities beyond the superuser root to all users.

Cron, ported to BSD, remained unchanged for the life of UNIX System V and its derivatives: Solaris, IRIX, HP-UX, and IBM AIX. Vixie cron (now called ISC Cron) were developed for Linux in 1987, and Redhat Linux has cronie and anacron, all of which have contributed to the growth in Linux server administration.

Cron Hosting Basics

There are three basic characteristics for the best web hosts for Cron, these are Linux hosting, cPanel hosting and unlimited hosting. However, this does not mean that you will never have the ability to run cron jobs if your hosting plan has one or two elements missing. From here on we will discuss the workarounds available for each criteria.

Windows and Cron

The scheduling service within MS Windows began as the AT command in MS-DOS, became the WinAT command in the NT versions of Windows, and eventually evolved into the Task Scheduler service built into the Windows operating systems from Win98 on.

Thus, if your host is not Nix-like and you need Cron, check out: Simple Ways to Set Up a Cron Job on a Windows Server

cPanel and Cron Commands

For those of you without Cpanel to easily configure your Cron, you will need shell access to go inside the crontab directly to configure it. Here are some basic commands and syntax for manually handling Cron:

- "crond start" (Starts the cron daemon)
- "crond stop" (stops the cron daemon)
- "ps aux | grep crond" (check to see if cron daemon is running)
- "crontab -l" (list all cronjobs set by root user)
- "crontab -u -l" (lists all cronjobs set by username)
- "crontab -e" (edit a cronjob for root user)
- "crontab -u -e" (edit a cronjob for username)
- "crontab -r" (remove all cronjobs of root user)
- "crontab -u -r" (remove all cronjobs of username)
- "crontab " (imports cronjobs from file for root user)
- "crontab -u " (import cronjobs from file for username)

The default editor software for editing cronjobs is vi.

A crontab file contains lines for definition of the environment and the runs.

The first four lines of a typical crontab file are:
SHELL=/bin/bash
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MAILTO=root
HOME=/

SHELL is the variable that specifies which shell environment should be used.
PATH is the variable defining the path for execution of specific commands.
MAILTO is the variable specifying the username which will receive any output via email. If empty (MAILTO=”"), then no email will be sent.
HOME is the variable that sets the home directory for cronjob execution.

All the lines that follow look like this:

42 4 1 * * root run-user /etc/cron.monthly >> /dev/null 2>&1

The format is:
Minute Hour Day Month Dayofweek User Command Location Output
where

• Minute: any integer from 0-59
• Hour: any integer from 0-23
• Day: any integer from 1-31 (max must be valid for any specified month)
• Month: any integer from 1-12 (or jan, feb, etc.)
• Dayofweek: any integer from 0-6 (or sun, mon, etc.)
• User: “root” or username
• Command: name of job to be run
• Location: directory where command is located
• Output: all output goes to trash can

More on Output:

“>> /dev/null 2>&1″ means the cronjob sends both standard output and error output to the trash can. If you want to save both the standard and error output, you can use “>> /home/user/some.log 2>&1″ instead.

An asterisk (*) can be used as a wildcard to denote all possible values — an asterisk in the Month position means every month of the year.

So, in the example given above, the job run-user, located in the /etc/cron.monthly directory, will be run at 4:42 AM on the 1st of every month.

A comma (,) can be used to create a list of values — for example, “4,5,6″ means 4, 5 and 6.

A hyphen (-) between two integers can be used to denote a range of values — for example, 2-5 means 2, 3, 4, and 5.

A forward slash (/) followed by an integer denotes step values — for example, 3/5 in the Hour field means the job is run first at 3 AM, again at 8 AM, again at 1 PM, and so on.

Every minute, the /etc/crontab directory is checked and read, then the /etc/cron.d directory and then the /var/spool/cron directory. Any entries found that match the current date/time will cause the specified file to be loaded into memory and executed.

Several other subdirectories are also checked periodically:
- /etc/cron.hourly
- /etc/cron.daily
- /etc/cron.weekly
- /etc/cron.monthly

Exit values returned by crontab are either zero (success), or a number greater than zero (error).

Cron and Email Management

As discussed, the output from Cron is automatically mailed to the process owner or the person specified in the MAILTO variable, as such cron jobs can be used to take care of standard email hosting and system maintenance functions, such as server backup, automatic email loads, and scanning incoming mail for malware and viruses. For email management, cron jobs can communicate with multiple websites, delete spam from mailboxes or distribute overnight content to subscribers — you can even use cron jobs to do monthly expired-member purges of your subscriber database, or summarize the demographics of your current mailing list. Any email management task that you can set up as a batch job, you can set up as a cron job.

Unlimited Resource and Cronjobs as a Service

If your host cannot handle the load of hosting unlimited resources, Cron has become an additional remote service offered by other online companies. For a fee, the service provider will allow you to schedule your own cron jobs over the Internet. With the extra service more attention must be paid, of course, to file locations when setting up the cron job, but the added flexibility this gives to webmasters more than makes up for the added complexity. Note that the key features to look-out for in choosing a good 3rd party cron job service are refresh rate, run time, quantity– how many jobs can be scheduled, and flexibility in the type of scripts to be run.

Related posts:

1. Performance Tip: Disable Optimizefs
2. Understanding Courier IMAP and Maildir
3. The cPanel Backup System

Install Subversion and Java

yum -y install java-1.6.0-openjdk java-1.6.0-openjdk-devel
yum -y install subversion

Install Ant

cd /opt
wget http://mirrors.kahuki.com/apache/ant/binaries/apache-ant-1.8.1-bin.tar.bz2
tar jxvf apache-ant-1.8.1-bin.tar.bz2
mv apache-ant-1.8.1 ant
ln -s /opt/ant/bin/ant /usr/bin/ant

Result: /opt/ant

Export some variables and add to bashrc:

export ANT_HOME=/opt/ant
export JAVA_HOME=/usr/lib/jvm/java
export PATH=$PATH:/opt/ant/bin
export CLASSPATH=.:$JAVA_HOME/lib/classes.zip

echo 'export ANT_HOME=/opt/ant' >> /etc/bashrc
echo 'export JAVA_HOME=/usr/lib/jvm/java' >> /etc/bashrc
echo 'export PATH=$PATH:/opt/ant/bin' >> /etc/bashrc
echo 'export CLASSPATH=.:$JAVA_HOME/lib/classes.zip' >> /etc/bashrc


Install Red5:

cd /opt
svn co http://red5.googlecode.com/svn/java/server/trunk red5
cd red5
ant prepare
ant dist


Create an init script

By default you have to use red5′s inherent scripts to start/stop, which can be a bit annoying. Create a file called /etc/init.d/red5 and past int he following:

#!/bin/sh
# For RedHat servers
# description: Red5 flash media server
# processname: red5
PROG=red5
RED5_HOME=/opt/red5
DAEMON=$RED5_HOME/$PROG.sh
PIDFILE=/var/run/$PROG.pid
# Source function library
. /etc/rc.d/init.d/functions
[ -r /etc/sysconfig/red5 ] && . /etc/sysconfig/red5
RETVAL=0
case "$1" in
start)
echo -n $"Starting $PROG: "
cd $RED5_HOME
$DAEMON >/dev/null 2>/dev/null &
RETVAL=$?
if [ $RETVAL -eq 0 ]; then
echo $! > $PIDFILE
touch /var/lock/subsys/$PROG
fi
[ $RETVAL -eq 0 ] && success $"$PROG startup" || failure $"$PROG startup"
echo
;;
stop)
echo -n $"Shutting down $PROG: "
killproc -p $PIDFILE
RETVAL=$?
echo
[ $RETVAL -eq 0 ] && rm -f /var/lock/subsys/$PROG
;;
restart)
$0 stop
$0 start
;;
status)
status $PROG -p $PIDFILE
RETVAL=$?
;;
*)
echo $"Usage: $0 {start|stop|restart|status}"
RETVAL=1
esac
exit $RETVAL

*Note that WordPress has a strange way of outputting double quotes, so make sure you address those in the script!
Now, chmod 755 /etc/init.d/red5 and run:

chkconfig red5 on

This will run Red5 on startup. With the init script, you can now start, stop, and restart red5 as needed, ex:

service red5 restart

red5 should now run port 5080 and rtmp service on port 1935. You may need to open these ports in your server’s firewall.

Test:

http://hostname:5080/demos/port_tester.swf

Source: Adapted from http://www.sohailriaz.com/how-to-install-red5-server-on-centos-53/

Related posts:

1. Setting Up Wildcard DNS with cPanel
2. cPanel: Installing Mod_Python on Apache 2
3. How to Change Your FTP Port

Create the Group

First, you’ll want to create your icon group.  The group will contain features/plugins that you create and assign to the group. Here’s a very basic example of a Twitter plugin that was created as part of a separate group called “Extras”:

First, we’re going to create the “Extras” group:

If you’re using the x3 theme, go into /usr/local/cpanel/base/frontend/x3/dynamicui . Create a file based on your new menu, prefaced with dynamicui, and ending in .conf. For example, I’m creating a group of icons that I want to be under a group called “extras”, so the file I create will be called dynamicui_extras.conf .

In the dynamicui_extras.conf file, all on one line, I’ll add the properties for my group, making sure everything is on one line:

groupdesc=>Extras,description=>extra icons,grouporder=>-100,group=>extras_menu,
imgtype=>icon,subtype=>img,type=>image,file=>extras,height=>32,width=>32

*Above info may be wrapped for display purposes, but in the file it should all be on one line

The settings here should be fairly self-explanatory, but here are the main elements:

• groupdesc: The label that will show up in cPanel for the group heading
• description: Describes the group (not shown in cPanel)
• grouporder: Where the group will show up in the cPanel interface (accepts negative values, lowest number is highest up)
• group: The name of the group, used when generating cPanel plugins

The rest of the values should be inputted as above, and just put the file value as the name of the group.  Now, save the file and reload cPanel. If you have active feature in this group, you should see the group and its icons appear when loading cPanel. If you don't see it, it means that either you don't have any features as part of the group, or your features are not configured correctly. So let's do that now!

Create Plugins (Features)

Cpanel plugins are basically items in cPanel that add functionality, and are enabled/disabled in WHM's Feature Manager. To create a plugin, simply use the cPanel Plugin Generator.  Notice that in the form, there's an option for Display Group - you can choose any of those for now, since you're just going to change it later.

Once you've generated and downloaded the plugin, open the plugin file and edit the group line.  This should reflect the value you put as group for the group you created earlier, so in my example, the line should read:

group:extras_menu

To install the plugin, copy the file to /usr/local/cpanel/bin and run:

/usr/local/cpanel/bin/register_cpanelplugin /usr/local/cpanel/bin/<pluginfilename>

You should now see the icon and group in cPanel. If you don't, you can try rebuilding the sprites:

/usr/local/cpanel/bin/rebuild_sprites

Resources:

cPanel Documentation: Installing Plugins

cPanel Documentation: Adding Icons and Groups

Related posts:

1. New cPanel Database Mapping Feature: Is it for You?
2. Adding Services to Chksrvd for Monitoring
3. Command Line PureFTP Configuration on cPanel

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