Tips to get Rid of Unused Kernel Images on Ubuntu

When you are working in an Ubuntu environment, you will find various ways of upgrading the kernel. The Software Updater helps you to update the kernel on daily basis. The unattended- upgrades package allows the upgrading automatically and this is an integral part of the security updates on Ubuntu server. You can even manually upgrade it using the aptitude command or apt-get.

Due to this continuous upgrade, you are sure to face the problem of disk space management. The upgrade is responsible for the accumulation of unused and old kernel images. Almost 200-400 MB of space is used by the kernel images along with the related modules.

So the disk space is wasted like anything and that is why you really need to get rid of the unused images to overcome the space constraint.

How to Get Rid of Old Kernel Images?

Kernel images can be removed with the help of many processes. Two of them are:


Before cleaning the images make sure that at least two images are intact. In Ubuntu various kernel image packages are installed.You have to use the command “$sudo apt-get purge Linux image- 3.19.0-15” to remove a version 3.19.0-15.The moment you remove an old kernel, the latest Linux kernel image will be installed whether you have upgraded it or not.

GRUB will also be triggered and will get automatically updated. It will also remove the old GRUB entry from GRUB menu. You can also remove multiple kernel images at one go using the shell expansion command.

Purge –old Kernels

You can also use a more user –friendly command-line tool known as purge-old –kernels. It is a part of a package called bikeshed. This is a random collection of many useful tools.

With the help of the purge-old-kernel, you can delete a configurable number of header files and old kernel images. To remove all and keeping the last three images you need to run “$sudo purge-old-kernels—keep 3”.

Use of all these tools can be learnt in depth if you take up RHCE training.

What You Need to Know about the Difference between RHCSA and RHCE?

Red Hat Certification is considered one of the best IT certification as it is completely based on hands-on lab exam. It is valued most by the IT industry and holding a Red Hat Certification definitely validates your skills in handling Red hat products and also Linux. You can be a proud holder of the Red Hat Certification when you prove your efficiency in executing practical world tasks and this is judged not through mere theoretical questions.

You need to take up the practical exams where your practical skills are judged. Thus the certification not only gives you a start in your Linux Career but also increases your market value. There are many certifications under Red Hat which makes you a qualified professional. Among all, the most valued ones are RHCSA and RHCE. Both the certifications have their base on RHEL. RHCSA and RHCE training in Hyderabad will give you the confidence to take up the exams.

Red Hat Certified System Administrator (RHCSA)

It is a very recent certification as it started in the year 2010 by replacing the original Red Hat Certified Technician (RHCT) certification. Although it is very new but has become very important. It has become the prerequisite for any other middle or higher level Red Hat certifications.

It is basically an entry level certification which requires no additional qualification. You have to appear for the EX 200 which is half day hands-on lab exam. The certification or the exam focuses on your ability of system administration. This includes installation and configuration of Red Hat Linux operating system.

Red Hat Certified Engineer (RHCE)

RHCE is an advanced level certification as it covers a wider syllabus. It gives you the ability to move from mid to advance level. The prerequisite for RHCE is RHCSA. Once you fulfill the condition you have to take up EX 300, which is again a hands-on lab oriented exam of two hours.

This exam focuses on topics like installation along with the security of the network. Being an RHCE, you are capable of all RHCSA tasks and also the following:

  • Setting the kernel
  • Configuration, network translation and packet filtering
  • Interface initiator
  • Shell scripting
  • Maintenance

To be successful in these two exams nothing but hard work and dedication are the key. It is advisable to enrol for RHCE training in Hyderabad or any authentic provider of the course.

Types of Red Hat Certification and Who Can Apply


A current survey of the IT industry has shown that around 75,000 Red Hat professionals are working in almost 162 countries. Most of the IT industries are adopting Linux and Red Hat certificate holders are considered to be the best in deploying Linux Red hat products. The Red hat Certification consider you for certification only when you clear the hands-on and practical exams. The program issues certification for Red Hat products and Linux related skills.


The different certifications from entry level to advanced level are listed for you.

Red Hat Certified System Administrator (RHCSA): An entry level certification that highly focuses on your efficiency at System administration and installing and configuring Red hat Linux products. You need to take up a half day hands-on lab test.

Red Hat Certified Engineer (RHCE): Considered as a flagship certification, ittakes you from mid to higher level. You need to clear a performance based test which will judge your capability of working on live systems .This RHCE Certificationwill guarantee your ability to configure the services related to Red Hat.

Red Hat Certified Data Center Specialists (RHCDS): As a RHCDS you have the skills and ability to build solutions in mission critical datacenter using Red Hat.

Red Hat Certified Administrator (RHCA): A master level program which gives hands-on training for senior administrators in Linux. It ensures that you can design and unfold Linux environment. This is programmed for technical seniors who are working in Linux environment.

Red HAT Certified Security Specialists (RHCSS): A more advanced level Red Hat Certification dealing with the security skills while using Linux in the enterprise environment.

Red Hat Certified Technician (RHCT): A program for those who are the beginners in Linux environments. You are certified when you take up a performance based test on live system.

Once you have passed 10+2 you can take up the above certification programs. To ensure your possibility to clear the exams it is better to enroll yourself with Linux course. The Red Hat also provides RHCE training that will help you to take the ‘hottest’ certification with confidence.