Thin provisioning uses virtualization technology to allocate disk storage capacity on demand as your needs increase. Thick provisioning is the counterpart strategy of pre-allocating storage capacity upfront when you create a virtual disk drive.

Thin provisioning creates the illusion of more physical resources than are available in reality. For example, you can assign 1TB of virtual disk space to each of the 2 development teams, while actually allocating only 500GB of physical storage. With thick provisioning, you would need to start with 2TB of physical storage if you wanted to assign 1TB to each of those 2 teams.

Before you make a decision, here are it’s top 2 advantages and its top 2 disadvantages:

Advantage #1: Optimizing your storage utilization

In environments where storage is shared, thin provisioning lets you optimize the usage of your available storage, so it’s not sitting idle. For example, say you assign a 2TB drive to an application that ends up using only 1TB of storage. In this configuration, another application can leverage unused storage. With thick provisioning, the unused capacity is never utilized.

Advantage #2: Scaling up cost-effectively

As long as you are monitoring and managing storage effectively and can confidently predict usage trends, thin provisioning lets you incrementally add more storage capacity as needed and not buy more than you need for the immediate future. 

Disadvantage #1: Increased downtime and data loss potential

Most approaches don’t automatically account for your growing storage needs—putting your environment at significant risk for storage shortages and associated downtime issues when the volume of virtual storage provisioned exceeds the physical disk space available. This includes crashes and/or data loss on your virtual drives that can hurt user productivity and customer experience while leaving your DBAs with a big mess to clean up.

Disadvantage #2: Lack of elasticity

As just noted, thin provisioning is great for helping you scale up your storage environment cost-effectively. But it doesn’t work in reverse. If your applications need fewer services, you may need to reduce the allocations manually as part of your storage monitoring and management program unless your array controller or other technology can handle that for you.

Choose thin provisioning based on the use case

As a general rule, whether to use thin or thick provisioning depends on the balance of resources used versus allocated for your specific use case. Thin provisioning is much safer and more efficient when the resources you actually need are significantly less than what you plan to allocate. Thick provisioning is a better choice when the resources you use are close to what you allocate.

This is why Buda Consulting doesn’t recommend thin provisioning for production storage except for clients that can consistently manage and forecast data storage needs. Otherwise, this can lead to major problems and expenses that outweigh the cost savings associated with improved storage utilization. However, thin provisioning can be a good option for many businesses when used in development, testing, or other non-production scenarios.

Next steps

For expert advice on how you can best leverage thin or thick provisioning, or to explore a range of options for making the best use of physical and virtual storage in your unique environment, contact Buda Consulting.