Project Capitola

What is VMware Project Capitola?

One of the big announcements coming from VMworld 2021 is the announcement of VMware Project Capitola. What is VMware Project Capitola? How will it introduce new features for how memory is managed in future versions of vSphere? Let’s take a look at what this new VMware Project is exactly and what new capabilities and features it will bring to the enterprise data center.

Memory is growing in importance

You might say, memory has always been important. And you are right. Memory is one of the fundamental resources that the world of computing cannot live without. It is equally important in the world of virtualization as well. Physical memory in VMware ESXi hosts is allocated to virtual machines. Virtual machine operating systems see the virtual memory allocated as the physical memory they have available, oblivious to the fact they are virtualized.

While memory has always been important in the data center, it is growing in importance for other reasons outside of the standard computing requirements it has been used for since computers came onto the scene. Memory is crucially important in the performance of workloads. It is also crucially important to how data is being consumed in enterprise applications.

Data has become the “new gold” of big businesses. Data can literally make or break a company as new data-driven models are responsible for the decisions organizations make and how money is spent. Enterprise applications consuming the enormous amount of data available to them need to be able to both store and process these vast stores of data as quickly as possible. Data living in memory is the quickest data access available to workloads today.

Memory challenges

Organizations today are now hitting roadblocks to data consumption, largely due to memory bottlenecks. Workloads may become memory-constrained and lack the memory resources needed. Organizations often run large databases in memory for the best performance. As databases grow, they require even more memory resources.

Memory is also one of the costliest components of new server hardware. As businesses provision new hardware, they generally overbuy on memory since they not only have to account for the amount of memory they currently use, but they need to consider future growth. Additionally, memory must be configured so that in a virtualization cluster, if you lose one host, the remaining hosts can assume the workloads and resource demands, including memory.

Another traditional memory constraint with current virtualization technologies is virtualized workloads are limited by the amount of memory that is available to a single hypervisor host.

What is VMware Project Capitola?

VMware Project Capitola is a new preview technology from VMware that helps to demonstrate where ESXi and vSphere cluster technology is headed in the area of memory management. As mentioned above, there are many technical challenges that can affect businesses related to the memory available and how this memory can be assumed.

VMware Project Capitola is set to change how organizations are able to utilize memory across their vSphere clusters and the memory that virtual workloads have available to them. You can think of VMware Project Capitola as the “vSAN of memory” in that it brings many of the same benefits to vSphere memory as vSAN has brought to storage.

VMware Project Capitola allows customers to effectively introduce memory tiering to the mix when allocating memory to workloads. What is memory tiering and why is it important? Memory tiering basically allows workloads of varying criticality and performance needs to have memory from different tiers to be allocated, based on those requirements.

Wait, isn’t there only one type of memory? Not exactly. Modern hardware advancements in the world of storage have allowed advancements to be made in memory. Ok, that sounds confusing. What does storage have to do with memory?

Storage class memory (SCM) is a new type of storage that is so fast, it can be used for memory in certain use cases. We are talking about solutions like Intel Optane to be more precise. This is also known as Persistent Memory (PMEM). Intel Optane and other forthcoming storage and memory technologies are extremely performant and, what’s more important, much less expensive than traditional DRAM.

Intel Optane Persistent Memory
Intel Optane Persistent Memory

Possible storage tiers:

  1. Tier 1 – DRAM – Most performant memory, most costly
  2. Tier 2 – PMEM – High performance that is less performant than DRAM, but much more cost-effective
  3. Tier 3 – NVMe – Slower than PMEM, able to be used in certain use cases as slow memory

VMware Project Capitola will be able to take these different memory “tiers” and manage them in such a way that workloads can be assigned to different tiers of memory based on their performance needs and criticality to the business. Less critical workloads from a performance perspective can be assigned to slower memory types.

In addition to providing memory tiering to the environment, VMware Project Capitola eventually will be able to extend memory pooling as a cluster-wide resource, and not just a single host resource. Tiers will aggregate the various memory types in each host, across the cluster.

The first phase of the VMware Project Capitola release will be implemented at the ESXi layer. The next phase will be released with cluster-level features. We can just imagine the possibilities this new way of managing memory will bring to vSphere environments. It will certainly add a great deal of flexibility and granularity to how businesses consume precious and expensive, memory resources.

Wrapping Up

VMware Project Capitola will become the vSAN of memory and will allow businesses to have capabilities that have never been possible with traditional vSphere memory management. Memory is becoming a resource that is quickly being consumed, due to the need to store and process data quickly. Modern applications are storing large amounts of data in memory for performance reasons.

With new storage class memory solutions now available, such as Intel Optane PMEM, organizations have many more options available to them for many use cases. Previously, there was only one type of memory, DRAM. PMEM devices though have closed the gap in performance and are now a viable solution for solving many of the memory contention problems seen in the data center.

To learn more about Project Capitola, take a look at these resources:

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Brandon Lee

Brandon Lee is the Senior Writer, Engineer and owner at and has over two decades of experience in Information Technology. Having worked for numerous Fortune 500 companies as well as in various industries, Brandon has extensive experience in various IT segments and is a strong advocate for open source technologies. Brandon holds many industry certifications, loves the outdoors and spending time with family.

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