April 12, 2023

vSAN 8 U1 Express Storage Architecture - Faster than Ever

Have you ever wondered just how much faster the vSAN Express Storage Architecture (ESA) is than the Original Storage Architecture (OSA) in vSAN?  This post summarizes some particularly challenging applications and workloads to give you a better understanding of performance differences when using the very same hardware.

A driving force behind VMware's effort to introduce a new architecture in vSAN was to allow our customers the ability to fully exploit the extraordinary capabilities of next-generation hardware being introduced into modern servers.  The novel way the Express Storage Architecture (ESA) in vSAN processes and stores data allows it to deliver capabilities unachievable with the Original Storage Architecture, or OSA.

While it hasn't even been 9 months since the introduction of vSAN 8, we've made the ESA in vSAN 8 U1 even faster.  Let's look at some practical examples that demonstrate the performance capabilities of the ESA in comparison to the OSA using the same version of vSAN and identical hardware configurations.

Performance Improvements in vSAN 8 U1

As described in the post "Performance Improvements with the Express Storage Architecture in vSAN 8 U1" VMware delivers new levels of performance primarily through two specific enhancements:  vSAN ESA's new Adaptive Write Path, and optimized I/O processing for single VMDK objects.  These improvements build off the impressive capabilities in its initial release and allow the ESA to race significantly ahead of the performance capabilities of the OSA.

How much so?  The examples below represent a cross-section of challenging application types found in many environments.  But the performance benefits of ESA are by no means limited to these applications.  You'll find the ESA can deliver better performance using fewer resources across all application types and workload conditions.

Video Surveillance Applications

videoThese types of solutions often generate large amounts of sequential writes, which for a storage system can be one of the most demanding types of workload profiles because it is writing a large amount of data using large I/O sizes.  When comparing performance with the OSA, we found the ESA delivers up to a 240% performance improvement.  Imagine driving up to 3.4 times the I/O using the very same hardware!  This improvement shows our new Adaptive Write Path capabilities introduced in vSAN 8 U1 in action, where it can identify when these types of write operations occur and use the most optimal write path for these conditions.

Apache Kafka

kafkaThe I/O characteristics of Apache Kafka share some similarities with video streaming applications, where they can place high demands on a storage system.  Distributed event streaming solutions like Kafka have been designed to scale out, and depending on the configuration, can generate extremely large amounts of data to be written continuously. When performing comparison testing, we found that the ESA delivers up to 80% better performance when running Kafka.  Once again, this demonstrates how well the ESA handles workloads generating high write throughput.

Healthcare Database Applications

healthcareSolutions using relational databases are the backbone of many applications across a wide variety of industries.  The healthcare industry relies heavily on Electronic Health Records (EHR) solutions to provide the very best patient care and exemplifies the notion of "mission critical."  vSAN has been an ideal platform for healthcare environments, and with the ESA, it gets even better.  Our testing has shown these database-dependent healthcare applications offer up to 50% better performance when running on ESA.  This is an extraordinary level of improvement given the highly transactional nature of these applications.

NoSQL Applications

NoSQLSome solutions use NoSQL to store their application data.  NoSQL can be highly scalable and is often found in several open-source and commercial applications.  We've found that NoSQL-based applications perform up to 15% faster using the ESA.  This is quite impressive given that CPU, memory, and network latency are often the most common performance impediments of a NoSQL environment. 

Beyond the Performance Improvements

While the performance numbers of ESA are quite stunning given the continual performance improvements introduced to the vSAN OSA, there are secondary benefits of the ESA that shouldn't be overlooked.

  • Reduced resource utilization.  The ESA consumes fewer hardware resources to process and store data.  This means that compared to the OSA, you may need fewer hosts to meet the very same workload requirements or be able to run more workloads on the same amount of hardware.  Both effectively lower your cost of ownership.
  • Improved performance consistency.  A more efficient storage stack reduces demand for physical resources like CPUs and can help improve the consistency of the performance delivered to the guest VMs.  This can be especially important for mission-critical systems that must not only have low levels of latency, but consistent levels of low latency.
  • Better space efficiency.  The vSAN ESA offers improved space efficiency without compromise.  Unlike the OSA, it can store data resiliently using RAID-5/6 erasure coding with the performance of RAID-1.  This provides guaranteed levels of space efficiency when storing data resiliently.  The ESA can also compress data with minimal resource utilization and even reduce network utilization.
  • Easier to manage.  The idea of performance without compromise also improves management.  Considerations and optimizations to achieve the best possible performance have become easier with the vSAN ESA, as noted in:  "Performance Recommendations for vSAN ESA." 


The Express Storage Architecture in vSAN 8 U1 is faster than ever.  Its potential in both performance and efficiency far exceed the capabilities of the Original Storage Architecture.  But the performance comparisons highlighted above represent far more than just impressive performance improvement to vSAN. In many ways, it is just the beginning of what the ESA can offer.  It unlocks all new potential for VMware to deliver new and innovative capabilities all using the software that you already know.  The future of vSAN and its Express Storage Architecture is bright indeed.



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