Did you know that if you have cPanel/WHM on your server, you also have a bunch of serverside commands that you can use?  These are good for advanced users, or the people who prefer to manage their servers in a hurry via the command line rather than waiting for a web interface to load.

Nearly everything that you can do in the WHM backend can be performed via command line.  These scripts are located in your server’s /scripts/ directory.  Only use scripts that have been verified by cPanel, or that you know yourself are safe as an unsafe script may damage your server.

Long list of scripts after the break…

Installing/upgrading perl is a pretty straight forward task and is necessary for cPanel to function properly.

root@ohhai [~]# wget http://layer1.cpanel.net/perl588installer.tar.gz
root@ohhai [~]# tar -xvzf perl588installer.tar.gz
root@ohhai [~]# cd perl588installer
root@ohhai [~]# ./install

If I remember correctly, the install takes 25-30 minutes to complete depending on your server setup.

Came across this issue at work where a client was receiving this message when trying to enter webmail, even though the e-mail account and cPanel account were not over quota.

Internal Server Error

User ‘useraccount’ is over quota.

This happens when the users ‘overquota’ status is cached and can be fixed by removing the users folder located at the following.

/var/cpanel/overquota/username

I had a client contact me earlier this morning because one of their clients was receiving the following error on their VPS when trying to run OpenVPN.

Note: Cannot open TUN/TAP dev /dev/net/tun: Permission denied (errno=13)
Note: Attempting fallback to kernel 2.2 TUN/TAP interface
Cannot open TUN/TAP dev /dev/tun0: No such file or directory (errno=2)

I’ve never run into this issue before, but was able to find an awesome tutorial on the OpenVZ website.

First, make sure the tun module has been already loaded on the hardware node:

# lsmod | grep tun

If it is not there, use the following command to load tun module:

# modprobe tun

To make sure that tun module will be automatically loaded on every reboot you can also add it or into /etc/modules.conf (on RHEL see /etc/sysconfig/modules/ directory) or into /etc/sysconfig/vz-scripts/VEID.mount.

echo 'modprobe tun' /etc/sysconfig/vz-scripts/VEID.mount

Allow your container to use the tun/tap device by running the following commands on the host node:

vzctl set VEID --devices c:10:200:rw --save
vzctl set VEID --capability net_admin:on --save

And create the character device file inside the container (execute the following on the host node):

vzctl exec VEID mkdir -p /dev/net
vzctl exec VEID mknod /dev/net/tun c 10 200
vzctl exec VEID chmod 600 /dev/net/tun

Enter cat /dev/net/tun to test whether the TUN/TAP device is available:

• If you receive the message cat: /dev/net/tun: File descriptor in bad state your TUN/TAP device is ready for use.
• If you receive the message cat: /dev/net/tun: No such device the TUN/TAP device was not successfully created.

I was getting the following error in a container on one of my nodes.

[root@server1 ~]# iptables -t nat -F
iptables v1.3.5: can't initialize iptables table `nat': Table does not exist (do you need to insmod?)
Perhaps iptables or your kernel needs to be upgraded.

[root@server1 ~]# iptables -t nat -nvL
iptables v1.3.5: can’t initialize iptables table `nat’: Table does not exist (do you need to insmod?)
Perhaps iptables or your kernel needs to be upgraded.

You can fix this by using the following commands.

[root@yoshi ~]# vzctl stop 150
[root@yoshi ~]# vzctl set 150 --iptables "iptable_nat iptable_filter iptable_mangle  ip_conntrack ipt_conntrack ipt_REDIRECT ipt_REJECT ipt_multiport  ipt_helper ipt_LOG ipt_state" --save
Saved parameters for VE 150
[root@yoshi ~]# vzctl restart 150
[root@yoshi ~]# vzctl enter 150
[root@server1 ~]# iptables -t nat -nvL
Chain PREROUTING (policy ACCEPT 0 packets, 0 bytes)
pkts bytes target     prot opt in     out     source               destination

Chain POSTROUTING (policy ACCEPT 0 packets, 0 bytes)
pkts bytes target     prot opt in     out     source               destination

Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes)
pkts bytes target     prot opt in     out     source               destination

Ever run into issues with typing in your root password, or forgot what you set it to, then got locked out of WHM? Well, here’s a quick and easy way to get your access back when receiving this error message.

This account is currently locked out because a brute force attempt  was detected. Please wait 10 minutes and try again. Attempting to login again will only increase this delay. If you frequently experience this problem, we recommend having your username changed to something less generic.

Run the following as root in SSH.

mysql cphulkd
mysql> delete from brutes;
mysql> delete from logins;

Below are the commonly used OpenVZ commands, which are run from the main node.

Shows list of all the VPS’s hosted on the Node.

vzlist -a

To start the VPS

vzctl start VEID

To stop (Shut Down) the VPS

vzctl stop VEID

To view the status of the particular VPS

vzctl status VEID

To stop the VPS quickly and forcefully

vzctl stop VEID –fast

To enter in a particular VPS

vzctl enter VEID

To set the Hostname of a VPS

vzctl set VEID –hostname vps.domain.com –save

To add a new IP to the hosting VPS

vzctl set VEID –ipadd 1.2.3.4 –save

To delete the IP from VPS

vzctl set VEID –ipdel 1.2.3.4 –save

To reset root password of a VPS

vzctl set VEID –userpasswd root:new_password –save

To add the nameserver IP’s to the VPS

vzctl set VEID –nameserver 1.2.3.4 –save

To run any command on a VPS from Node

vzctl exec VEID command

To install any package/Software on a VPS from Node

vzyum VEID install package_name 

**VEID refers to the ID of the Particular VPS**

So…I came across this error on a clients site which he was receiving when trying to install a 3rd party script.

The session.save_path setting in your php configuration file (php.ini) is not set or is set to a folder which did not exist. You might need to set the save_path setting in php.ini or verify that the folder sets in save_path exist.

It’s a pretty simple fix in the servers php.ini.

A fantastico installation is pretty straight forward. First thing you need to do is obtain a Fantastico license from Netenburg.

One of the most common issues when installing fantastico is a buggy wget install on the server, so a working wget version will need to be installed. Another common issue is cPanels internal php may break, but we will discuss the fix to that later on.