Permission denied (publickey,gssapi-keyex,gssapi-with-mic)

When trying to log into a server with WHM/cPanel via SSH and you get this error:

Permission denied (publickey,gssapi-keyex,gssapi-with-mic)

This will be because password authentication is disabled in the sshd_config file

To resolve this you can log into WHM and enable the password authentication.

  • WHM >> Security Center >> SSH Password Authorisation Tweak

Then restart the SSH service.


WARNING: RESTRICT_SYSLOG is disabled. See SECURITY WARNING in Firewall Configuration in WHM

When looking at “ConfigServer Security & Firewall” in WHM it gives this error at the top in a yellow box WARNING: RESTRICT_SYSLOG is disabled. See SECURITY WARNING in Firewall Configuration

I resolved this by:

  • Setting RESTRICT_SYSLOG to 3 in the drop down box

This is a description of each number in the drop down box:

# 0 = Allow those options listed above to be used and configured
# 1 = Disable all the options listed above and prevent them from being used
# 2 = Disable only alerts about this feature and do nothing else
# 3 = Restrict syslog/rsyslog access to RESTRICT_SYSLOG_GROUP

How to fix Windows 2008 R2 BOOTMGR is missing in VMWare

When rebooting a virtual machine in VMWare and it gives the error message:

Bootmgr is missing 

Press Ctrl+Alt+Del to restart

You can try BCDBoot:

  1. Right click on the virtual machine and select “Edit settings” under “Hardware” change the device type to “Datastore ISO File” then choose Windows 2008 R2.
  2. Restart the VM and press “Esc” when it boots to get the boot menu.
  3. Choose to boot from “CD-ROM”
  4. You will need to click on repair Windows but cancel any menus to get the cmd.
  5. Using the command prompt type BCDBoot c:\Windows then press “enter”

This should then re-install the files needed to boot. You will need to shutdown the VM and then disconnect the Datastore ISO File type back to the client device and reboot the VM.

Find Out Hard Disk Details on Linux

The hdparm command provides a command line interface this command read / request identification information such as disk size, description and much more directly from the drive, which is displayed in a new expanded format.

To show this information use the following command:

hdparm -I /dev/sda

hdparm -I /dev/sdb

lshw Command

You need to install lshw command using your package manager. To display all disks and storage controllers in the system using the following the command:

lshw -class disk -class storage

Find out disks name only 

Use the following command:

lshw -short -C disk

smartctl Command

smartctl -d ata -a -i /dev/sda

Hardware Details without turning the server off

dmidecode is a tool for dumping a computer’s DMI table contents in a human-readable format.

To show just the memory information use the following command:

dmidecode –type memory

To show the memory information using the number use this command:

dmidecode 17

Here is a table of the types:

 Type   Information
0   BIOS
1   System
2   Base Board
3   Chassis
4   Processor
5   Memory Controller
6   Memory Module
7   Cache
8   Port Connector
9   System Slots
10   On Board Devices
11   OEM Strings
12   System Configuration Options
13   BIOS Language
14   Group Associations
15   System Event Log
16   Physical Memory Array
17   Memory Device
18   32-bit Memory Error
19   Memory Array Mapped Address
20   Memory Device Mapped Address
21   Built-in Pointing Device
22   Portable Battery
23   System Reset
24   Hardware Security
25   System Power Controls
26   Voltage Probe
27   Cooling Device
28   Temperature Probe
29   Electrical Current Probe
30   Out-of-band Remote Access
31   Boot Integrity Services
32   System Boot
33   64-bit Memory Error
34   Management Device
35   Management Device Component
36   Management Device Threshold Data
37   Memory Channel
38   IPMI Device
39   Power Supply

If you require further help you can use the following command:

man dmidecode

Install (LAMP) stack On CentOS 7

Install Apache

To install Apache run the following:

sudo yum install httpd

Once it installs, you can start Apache on your server using:

sudo systemctl start httpd.service

To test that the web server is working use:


If you see the Apache test page, then your web server is now correctly installed. Now enable Apache to start on boot using the following:

sudo systemctl enable httpd.service

How To Find your Server’s Public IP Address

If you do not know what your server’s public IP address is you can use:

ip addr show eno1 | grep inet | awk ‘{ print $2; }’ | sed ‘s/\/.*$//’ or curl

Install MySQL (MariaDB)

MariaDB is a community-developed fork of the MySQL relational database management system. To install MariaDB use the following:

sudo yum install mariadb-server mariadb

After installation you start MariaDB with the following command:

sudo systemctl start mariadb

Run a simple security script that will remove some dangerous defaults by

sudo mysql_secure_installation

It will ask for current root password so just press enter for none and then
it will prompt you to set a root password.

Then you want MariaDB to start on boot by using the command:

sudo systemctl enable mariadb.service

Install PHP

To install PHP you need to run the following:

sudo yum install php php-mysql

Once that is installed you will need to restart the web server using:

sudo systemctl restart httpd.service

Test PHP Processing on your Web Server

If you’re not running WHM/cPanel or Plesk then run:

sudo vi /var/www/html/info.php

Put this code into the empty file:

<?php phpinfo(); ?>

If youre running a firewall then you may need to run these commands:

sudo firewall-cmd –permanent –zone=public –add-service=http

sudo firewall-cmd –permanent –zone=public –add-service=https

sudo firewall-cmd –reload

To test this go to:


Then if everything is ok then remove the php file using:

sudo rm /var/www/html/info.php

The reason this file is removed is because sometimes it can reveal information about the server we do not want unauthorised people to know.

Done LAMP is now installed on your server.