No ClusterStor cuckoo in Qumulo’s HPE nest

HPE’s upcoming purchase of Cray and its ClusterStor high-performance computing arrays could affect its supplier Qumulo.

HPE will have four scale-out filesystem products to sell:  its own Scalable Storage for Lustre, two partnership-supplied offerings from Qumulo and WekaIO Matrix, and Cray ClusterStor.

Blocks & Files asked Qumulo how it saw the scale-out file system situation with HPE buying Cray, and we received a reply from Molly Presley, Qumulo’s director of product marketing, shrugged off our suggestion that ClusterStor was a cuckoo in HPE’s storage nest.

No ClusterStor cuckoo here

Molly Presley

She saw three trends affecting file system storage:

  • Customers want the freedom of software defined storage (aka, they want to avoid vendor lock-in on hardware and the associated uncontrolled support price increases that occurs on proprietary hardware from some vendors beyond year 3)
  • High-performance applications are designed today and over the past several decades to write to file systems. File counts and size of unstructured data has accelerated far beyond the limits of many legacy file, NAS, scale-out and scale-up architectures.
  • The cloud is an important part of infrastructure today, or in the near term planning for most data driven organisations.

In her view, ClusterStor, Weka and Qumulo all are driven by these trends. But similarities pretty much stop there. Presley explained Qumulo’s thinking on its differentiation from ClusterStor and WekaIO below.

ClusterStor and Lustre

ClusterStor is a branch of the Lustre open source code. It has its own features and code branches that are only merged with the main tree of Lustre code on a very infrequent basis. ClusterStor is essentially an appliance made and supported by Cray to simplify Lustre deployment, and for users who want support for the open source Lustre code and who already have a relationship with Cray for their supercomputing technology. 

The use case for Lustre is for extremely high performance, supercomputing users that have a very high number of users. It is a workhorse file system that requires deep administrative expertise, requires client software be loaded on all client machines, and has very few enterprise high availability or data protection features built in.

Presley pointed out that Robinhood tiering has proven to not be robust; typically third party applications are needed for data protection; there are no snapshots, very limited NAS integration work with directory services, NAS security and cross protocol locking for mixed SMB and NFS environments.

It is really designed for in-data centre deployment on Fibre Channel or InfiniBand networks to connect to super computers. 

With the purchase of Cray by HPE, perhaps ClusterStor in the future will be sold elsewhere, but today, it is sold as part of a larger supercomputing deployment in large HPC data centres.  Time will also show if the Lustre-based ClusterStor file system gets significant traction with Cray compute in Azure.


Weka is a new file system, written cloud-native, that appears to have been purpose designed to compete against Lustre in these extreme performance, HPC environments.  They are in a spec war showing who has the fastest benchmarked performance numbers.  

Weka is high performance but [it’s] very expensive to build that performance.  Weka is focused on extreme IO acceleration and low latency. It is a model targeted toward supercomputing scratch space primarily, and, secondarily, applications which need a burst buffer. 

In a panel discussion with Weka, DDN, Qumulo and WD’s object storage division in Texas this spring, Weka was focused on their focus on being a burst buffer as an alternative to IME

It requires NVMe storage and substantial amounts of memory to achieve the posted performance numbers. It then has an offload to [an] object storage function for long term retention. 

Weka has snapshots but lacks replication, quotas and many of the NAS protocol deeper capabilities mentioned above. Weka typically is displacing GPFS, Lustre or competing against BeeGFS and DDN.


Blowing her own trumpet, so to speak, Presley said Qumulo is designed to meet the demands of the much larger scale-out NAS and distributed file system market. It offers very simple to deploy and manage offerings both on-prem and in the cloud. 

Qumulo typically is displacing NetApp and Isilon, competing against Pure and Nutanix. Qumulo is designed to integrate into enterprise environments that have both Macs and PCs with their strong SMB and NFS support. Extensive work has been done to integrated into directory services, maintain enterprise access permissions, assign usage quotas. 

[It] is built for both business units with large unstructured data (automotive, life sciences) and bumps into Weka and Lustre in these environments competitively. Qumulo has a much larger TAM as it also is very successful in video surveillance (which doesn’t need the extreme performance), M&E (which has extensive Mac users), Healthcare and Enterprise environments (which require deep enterprise NAS integration, high availability and complete enterprise data protection services).

Blocks & Files net:net

So there you have it. Qumulo argues that there is substantial differentiation from Lustre-based systems like ClusterStor, which is not enterprise-capable. It also differs from newcomer WekaIO which focuses purely on high-performance, unlike Qumulo, which competes with mainstream NetApp ONTAP and Dell EMC Isilon systems.

Our take is that Qumulo believes HPE will still need to partner with Qumulo in these sales opportunities because both Weka and Lustre systems have insufficient functionality in this mainstream scale-out filer space.