Oracle Linux KVM & OLVM advantages, benefits, important information : hard partitioning, Hypervisor type, Intel Vt-x or Vt-d , OCI migrations and so on.

We talked about these subjects in our webinar last week. We talked about the advantages of using Oracle Linux KVM and the real life stories based on our Oracle Linux KVM implementations.

Actually, I met KVM in 2017 during my ODA X6 implementations.. 

Remember that post -> 

ODA- KVM Virtualization for ODA X6-2S/X6-2M/X6-2L !!

I also wrote a blog post about the upcoming end date of OVM. 

Let's remember that as well ->

Upcoming End date of OVM Premier Support. It is time to consider KVM + OLVM (especially for the new projects)

Today, I will share some more insights with you .. 

As mentioned, the actual motivation of this blog post is the benefits that we have gained using Oracle Linux KVM and OLVM in our projects.

Let's start and go over the important information about Oracle Linux KVM .. (I will also try to give asnwers to some questions that may come to mind on the way..)

Oracle Linux KVM is the new virtualization techology of Oracle.

It is based on Oracle Linux and it is available through a kernel module ( kvm.ko)

KVM is the acronym for Kernel-Based virtual machine.. 

It is considered in the Type 1 category. Yes.. I know there is a confusion on this topic. We might say that KVM is not directly running on Bare Metal.. However; it is categorized as Type 1 because it is based on a Kernel module.. When we look from this perspective, KVM is running in kernel mode on bare metal and uses a hardware virtualizer. Besides, KVM guests are mostly running in direct execution mode.

Reference the following document (an old but good one) for other opinions on this topic; 

KVM reignites Type 1 vs. Type 2 hypervisor debate

So, KVM is a HW assisted full virtualization solution. (There are also paravirtualized virtualization drivers). It provides virtualization with qemu, a loadable kernel module and Linux. It speeds up the access to physical host .. (kvm.ko)

It requires Intel Vt-x (HW assisted virtualization) and it supports Intel Vt-d (PCI Passthrough).

KVM is an open source software. The kernel component of KVM has been included in mainline Linux from 2.6.20. The Userspace component is included in the mainline Qemu from 1.3 onwards. 

Let's make a quick overview about the features of KVM;

• Supports 32 and 64 bit guests. (On 64 bit hosts)
• Supports Full + Hardware Assisted Virtualization
• Supports paravirtualized drivers (virtio)
• Virtual Machine Snapshot feature available
• VM Live/online migration feature
• VM cloning feature
• Virtual machines can be set up with templates.
• Supports PCI passthrough.
• Supports Kernel samepage merging.
• It is very fast because it is a Type 1 virtualization (Like VMware and Hyper-V…)
• "Zero" License Cost (Open Source)

Let's take a quick look to the advantages of Oracle Linux KVM;

• Complete server virtualization and management solution with zero license costs
• Single software distribution for Oracle Linux OS or Oracle Linux KVM
• Single vendor Support. ( Oracle Linux support included Oracle KVM support). That isw we can create SRs about Oracle Linux KVM using Oracle Support!

• Virtual machine cloning feature and ready + customizable templates to speed up the development and provisioning processes ..
• Easy to implement and install.
• Easy to manage and configure using Oracle Linux Virtualization Manager and Enteprise Manager. ( strong GUI - OLVM)

• Provides ability to apply patches with Ksplice without service interruption. (Ksplice is used in Autonomous Linux in OCI as well..)
• Hard Partitioning support provides efficient Oracle application and database licensing. (CPU Pinning - using olvm-vmcontrol)
  
• Full Stack management with Oracle Enterprise Manager.
• It is the virtualization technology that is used in Oracle Cloud Infrastructure!
• Thick and thin provisioning.. (setting VM memory sizes in a way similar to what we do in the data layer sga_target and sga_max_size - style memory configurations for VMs)
• Easy migration option for migrating virtual machines from on-prem to Oracle Cloud Infrastructure. (using cloud-init - imex4vm!)

• Used in Oracle Enginereed Systems (so it is stable)
• Oracle Database is supported & certified to run on KVM !

What we have gained by using KVM as the virtualization solution in our Projects?

As mentioned, we have made projects using Oracle Linux KVM and currently we are running mission critical production RAC databases and applications on it.. We have also implemented clusters and DR platforms on top of it. So let's se what we have gained...

• Quick installation (Level 1 Linux admistration knowledge is almost sufficient)
• Quick provisioning
• Hardware Compatibility
• Good documentation for KVM and OLVM
• Single Vendor Support
• Easy memory management for guest VMs
• Successful disaster recovery implementations and tests.
• Easy to use and user friendly interface
• Virtualization with hard partitioning (aligned with the Licenses)
• Complete compatibility and ability to ease OCI migrations.

All in all, there are many reasons to use Oracle Linux KVM for the virtualization layer. On the other hand, I don't see any reason not to use it.(especially for Oracle customers..)

One more thing..

Actually an aswer for of the questions you may ask;

Do we support and recognize KVM as a license partitioning technology on Redhat Linux or is it only Oracle Linux with Oracle Linux Virtualisation Manager running?

Asnwer : Hard Partitioning is only supported with Oracle Linux KVM .. ( + we need to use the Oracle Linux Virtualization Manager - olvm-vmcontrol to enable the CPU pinning)

That's it.. Please feel free to ask your questions.. If you have questions, you know what do to right? :)

For your questions, please create an issue into my forum.

Forum Link: http://ermanarslan.blogspot.com.tr/p/forum.html

Register and create an issue in the related category. ( I just created a separate category for Oracle Linux KVM and OLVM)

I will support you from there.