Scale-Out NAS Compared: Qumulo vs NetApp vs VAST Data in 2026

When evaluating scale-out NAS platforms, Qumulo, NetApp ONTAP, and VAST Data represent three distinct architectural approaches. Whether you’re planning a new deployment, refreshing existing infrastructure, or migrating from another platform like Dell Isilon (PowerScale), understanding the trade-offs between these platforms helps you make an informed decision.

This guide compares the three on the dimensions that matter most: protocol support, scalability, data services, cloud integration, and migration path.

Why This Comparison Matters

The scale-out NAS market offers more choices than ever. Each platform makes different architectural bets — proven maturity (NetApp), modern simplicity (Qumulo), or next-generation performance (VAST Data). The right choice depends on your workloads, operational model, and growth trajectory.

Comparison Overview

Qumulo

Overview

Qumulo was founded in 2012 by former Isilon engineers. The architecture is intentionally “Isilon done right” — a single scale-out file system with a global namespace, but built on modern foundations with real-time analytics built into the data path.

Strengths

Real-time analytics. Every metadata operation is tracked as it happens. The Qumulo UI shows real-time capacity consumption, file distribution, throughput, and hot spots — no batch scanning required. For organizations migrating from Isilon + InsightIQ, this is a significant improvement.

Simple scaling. Add nodes to the cluster and capacity + performance scale together. No rebalancing, no data migration between tiers. Qumulo handles data placement automatically.

Hybrid cloud. Qumulo runs natively on Azure (Azure Native Qumulo) and AWS, using cloud-native storage as the backing tier. The same management interface and API work on-prem and in cloud.

Protocol support. NFS (v3, v4.1), SMB (2.x, 3.x), S3, and FTP — all accessing the same global namespace. NFSv4.1 ACLs are fully supported, making Isilon multiprotocol migrations more straightforward.

Simplicity. Qumulo positions itself as “no tuning required.” There are no storage pools, aggregates, or volumes to configure. It’s a single file system.

Considerations

Qumulo focuses on file protocols (NFS, SMB, S3, FTP) and does not offer block protocols (iSCSI, FC, NVMe-oF). Organizations needing SAN and NAS from one platform should evaluate accordingly.

Migration Path from Isilon

Qumulo supports standard NFS and SMB ingest, so any migration tool that speaks these protocols can move data from Isilon to Qumulo. syncopio’s parallel dataset model is well-suited here — each Isilon export becomes a separate dataset transferring in parallel, with checksum verification on every file.

NetApp ONTAP

Overview

NetApp is the largest pure-play storage vendor and has been in the market since 1992. ONTAP (formerly Data ONTAP) is their flagship OS, running on FAS (hybrid flash), AFF (all-flash), and ASA (SAN-optimized) hardware, as well as in cloud (CVO, ANF, FSx for ONTAP).

Strengths

Maturity and ecosystem. ONTAP has 30+ years of enterprise deployments. Backup vendors (Veeam, Commvault, Veritas), enterprise applications (SAP, Oracle, VMware), and management platforms (NetApp Console, formerly BlueXP) have deep ONTAP integration.

Data services. SnapMirror (replication), SnapVault (backup), FabricPool (cloud tiering), MetroCluster (disaster recovery), FlexClone (space-efficient clones) — the data services stack is the most mature in the industry.

Multiprotocol. ONTAP supports NFS, SMB, S3, iSCSI, FC, and NVMe-oF on the same cluster. The unified architecture lets you serve file and block workloads from the same hardware.

Cloud integration. Cloud Volumes ONTAP runs ONTAP in AWS, Azure, and GCP. Azure NetApp Files (ANF) and Amazon FSx for NetApp ONTAP are cloud-native managed services. FabricPool provides transparent tiering of cold data to object storage.

Data reduction. ONTAP’s inline deduplication + compression + compaction routinely delivers 3-5x data reduction for general-purpose file workloads, significantly reducing effective cost per TB.

Considerations

ONTAP’s depth of features means there are more concepts to learn (aggregates, volumes, LIFs, vservers, export policies). The newer ONTAP One licensing simplifies the licensing model. ONTAP clusters support up to 24 nodes (12 HA pairs) — for exabyte-scale single-namespace workloads, evaluate whether FlexGroup volumes meet your requirements.

Migration Path from Isilon

ONTAP accepts data via standard NFS and SMB, making it compatible with any migration tool that supports these protocols. For large Isilon-to-ONTAP migrations with multiple exports, syncopio’s parallel dataset approach lets you migrate all exports simultaneously with built-in verification.

VAST Data

Overview

VAST Data, founded in 2016, takes a fundamentally different architectural approach. Rather than scaling out with identical nodes (like Isilon and Qumulo), VAST disaggregates storage into separate stateless compute (protocol servers) and stateful data nodes, connected by NVMe-oF fabric.

Strengths

Performance. VAST is all-flash, all the time. There’s no tiering between SSDs and HDDs. The combination of NVMe storage + disaggregated architecture + global deduplication delivers consistent low-latency performance at scale.

Simplicity at scale. Despite the sophisticated architecture, VAST is operationally simple: a single global namespace, no aggregates or pools, no tiering policies. Add servers for compute, add shelves for capacity.

Global deduplication. VAST performs similarity-based data reduction across the entire namespace. For workloads with significant data redundancy (genomics, media, backups), this delivers exceptional effective capacity.

Multiprotocol convergence. NFS, SMB, S3, and NVMe/TCP all access the same namespace with unified permissions. A file written via NFS is immediately accessible via S3 with the same access controls.

AI/ML readiness. VAST positions itself as the data platform for AI workloads. The InsightEngine adds semantic search, tagging, and catalog capabilities on top of the storage layer.

Considerations

VAST is an all-flash platform with no HDD tier — data reduction (QLC flash + global dedup) is central to its cost model. Evaluate your data profile to determine effective cost per TB. VAST’s integration ecosystem is growing rapidly alongside its expanding customer base.

Migration Path from Isilon

VAST supports NFS, SMB, and S3 ingest, making it straightforward to migrate from Isilon. VAST’s high-throughput architecture can absorb multiple parallel transfer streams without queuing — a good match for syncopio’s parallel dataset model.

Cloud-Native Alternatives (Brief)

If your workloads can move to cloud, consider managed file services:

AWS

Amazon FSx for NetApp ONTAP — full ONTAP in AWS, supports NFS, SMB, iSCSI. Best for organizations already using ONTAP on-prem.

Amazon FSx for Lustre — high-performance parallel file system for HPC/ML workloads. Not a general-purpose Isilon replacement.

Amazon EFS — managed NFS. Simple, scalable, but limited to NFSv4 and no SMB support.

Azure

Azure NetApp Files (ANF) — NetApp-powered NFS/SMB in Azure. High performance, SnapMirror integration with on-prem ONTAP.

Qumulo on Azure — full Qumulo experience running natively on Azure infrastructure.

Azure Files — managed SMB/NFS file shares. Good for general file serving, not for HPC-class workloads.

Google Cloud

Google Cloud Filestore — managed NFS. Simpler feature set than ANF or FSx, but easy to provision.

Google Cloud NetApp Volumes — NetApp-powered NFS/SMB on Google Cloud.

Decision Matrix: By Workload

Different workloads tend to favor different platforms. This is a general guide based on common market positioning — all three vendors can serve most of these workloads, so evaluate based on your specific requirements:

Migrating the Data

Regardless of which destination platform you choose, the data migration itself is the same challenge: moving petabytes of files from Isilon NFS exports and SMB shares to the new platform, with permission preservation and verification.

Traditional tools like rsync and Robocopy work but are limited: rsync is single-threaded with no parallelism across exports, Robocopy is Windows-only with no checksum verification, and neither provides a dashboard or audit trail.

syncopio is purpose-built for this. Each Isilon export becomes a dataset, datasets transfer in parallel across workers, and every file is checksum-verified during transfer. The web UI gives you real-time progress per dataset, and the audit trail satisfies compliance requirements. See our complete Isilon migration guide for the step-by-step process.

Making the Decision

There’s no universal “best Isilon replacement.” The right choice depends on:

1. Your primary workload — file services, media, HPC, AI?
2. Your protocol requirements — NFS only, SMB only, or multiprotocol?
3. Your scale — single-digit PB or exabyte-class?
4. Your ops team — do you have storage specialists or generalist admins?
5. Your cloud strategy — on-prem only, hybrid, or cloud-first?
6. Your budget model — CapEx, OpEx/subscription, or mixed?

If you’re unsure: start with the workload decision matrix above. Then do a proof-of-concept with your actual data and access patterns. All three vendors offer POC programs — take advantage of them.

Further Reading

• Dell Isilon migration guide — end-to-end migration lifecycle
• Isilon multiprotocol permissions — ACL migration deep dive
• rsync vs rclone vs Robocopy — migration tool comparison
• Storage trends 2026 — NAS market and industry direction

All product names, logos, and brands are property of their respective owners. This comparison reflects publicly available information as of March 2026 and is provided for informational purposes only.