Virtualization

Virtualization the most common word you hear these days in storage field. It combines all available resources to provide common abstract pool which can be deviced and categorised for specific requirements to be better utilized.

There are three types of virtualization

1. Server virtualization

2. Network virtualization

3. Storage virtualization

How did these three evolve? Basically SAN consists of three main entities the server, the network and storage, virtualization found its way in all of then as we went ahead innovating and utilizing the existing entities according to our needs at the fullest.

Server virtualization

Also know as host virtualization. The first one that comes into our mind is VMWare. The simple reason behind host virtualization was the processors became powerful and faster, but still they were dedicated for single application which inturn let most of available host resource under utilized this is commonly know as "server sprawl". But due to the nature of the applications, for easy tracking we still needed them to be run independently. Their complexity also leads them to be run independently to ease the life of administrators.

Then came in server virtualization and we have three types in them too. They are full virtualization, para-virtualization and OS-level virtualization. I am going too deep into them for now.

But I will take the common one full virtualization which is provided by a software that runs on the host/server. This software interacts with the physical hardware resources and creates virtual servers by dividing the available physical resources. Thereby utilizing the powerful physical resources to the full extent. There are few downsides but its better to be managed intelligently than being under-utilized.

Both VMware and concepts like NPIV leverage to server virtualization.

Network virtualization

Network virtualization is where we combine available resources in network and then by splitting and utilizing the available links/channels and bandwidth independent to each other. Each network resource is secured and available for specific purpose.

We can simply say the whole network is considered to be a single pool of resources that can accessed without any problem of being different in product or technology. This is managed and shared with storage and host by installing specific softwares.

One of switch/network level virtualization which we saw in earlier blog was Node port virtualization

Storage virtualization

SNIA had the best way to explain this and read by me so far. The same rule applies here as network. It just combines all available storage and abstracts from the vendors to provide common layer for management and utilization.

This covers various techniques starting with SSDs which are used as cache controllers, RAID, logical paritioning, SAN virtualization, Vitual tapes[VTL], virtual ports, virtual file system and others.

Oooooofff!!!! that was something. Though I think its simple, when ever I get into explain or write about it becomes tooo much. Just because the way virtualization is so and called for.

Adios 0:)

NOTE: I will update this post again to provide clarity and be simpler. Will add some pictures too.