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Cloud · head to head

Longhorn vs VerneMQ

Longhorn logo

Longhorn

Cloud

Open source distributed block storage for Kubernetes, incubating at the CNCF

From
Free
Rated
-
Full reviewWebsite
VerneMQ logo

VerneMQ

Databases

Erlang MQTT broker whose source is Apache 2.0 but whose official binaries need a paid subscription

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Longhorn there is no vendor and no SLA, so a production incident at three in the morning is your own problem unless you buy SUSE Rancher Prime support separately.; VerneMQ the official binaries and Docker images are not Apache 2.0 but sit under a EULA requiring a yearly commercial subscription, a distinction easy to miss and awkward to discover during a licence audit.
  • They diverge on capability: Longhorn covers Per-volume controllers, VerneMQ covers Erlang/OTP clustering.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which Longhorn and VerneMQ actually diverge.

Attributes where Longhorn and VerneMQ differ
AttributeLonghornVerneMQ
Pricing modelOpen source, no licence feequote
PlatformsLinux, KubernetesLinux, Docker, macOS, Kubernetes
CategoryCloudDatabases

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Longhorn

  • Per-volume controllers
  • Synchronous replication
  • Snapshots and backups
  • Volume expansion
  • Disaster recovery volumes
  • Web interface

Only in VerneMQ

  • Erlang/OTP clustering
  • MQTT 5.0 support
  • Plugin system
  • Backpressure handling
  • Bridge support
  • Metrics export
  • MQTT over WebSockets
  • Pluggable auth backends

What people use each for

The jobs each tool is most often brought in to do.

Longhorn

  • An on-premises Kubernetes cluster with local disks and no SAN that needs replicated persistent volumesnot VerneMQ
  • Edge sites where shipping a storage array is impractical and three nodes is the whole clusternot VerneMQ
  • A K3s deployment where the storage layer must be light enough to run alongside the workloadsnot VerneMQ
  • A team that wants snapshots and S3 backups of persistent volumes without paying per-node storage licencesnot VerneMQ

VerneMQ

  • An industrial operator that wants an MQTT broker with predictable memory behaviour and no data integration features it will not usenot Longhorn
  • A team building from source to stay strictly under Apache 2.0 terms with no vendor licence entanglementnot Longhorn
  • A deployment needing custom authentication logic implemented as a plugin in Lua or over a webhooknot Longhorn
  • An organisation that wants a broker maintained by a small European company rather than by a vendor that keeps changing licencesnot Longhorn

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Longhorn

  • There is no vendor and no SLA, so a production incident at three in the morning is your own problem unless you buy SUSE Rancher Prime support separately.
  • Synchronous replication across nodes means write latency depends on the slowest replica and the network between nodes, which makes it a poor fit for latency-sensitive databases.
  • Every replica is a full copy, so three-way replication consumes three times the raw capacity, unlike erasure-coded systems that are far more space efficient.
  • It is designed for block storage on modest clusters and does not scale to the node counts or throughput that Ceph or a commercial array handles, so growth eventually forces a migration.
  • Recovery from certain degraded states, such as a volume stuck detaching or replicas failing to rebuild, requires manual intervention and knowledge of Longhorn internals that is not widely held.

VerneMQ

  • The official binaries and Docker images are not Apache 2.0 but sit under a EULA requiring a yearly commercial subscription, a distinction easy to miss and awkward to discover during a licence audit.
  • Octavo Labs is a very small company, so support depth, response times and the bus factor on the codebase are materially thinner than at HiveMQ or EMQ.
  • There is no data integration or rule engine layer, so routing messages into a database means writing and operating your own consumer service.
  • Operating an Erlang cluster requires runtime knowledge that most teams do not have and will use for nothing else in their stack.
  • There is no vendor-managed cloud offering, so every deployment is self-operated with the infrastructure and on-call cost that implies.

Pricing, plan by plan

Longhorn

Free
  • LonghornFree
    • Apache 2.0 licensed, no licence fee
    • Community support via GitHub and Slack only
    • No vendor SLA or escalation path

VerneMQ

Free
  • Source buildFree
    • Apache 2.0 licensed source from GitHub
    • Full clustering and plugin capability
    • You compile and package it yourself
  • Binary packages and Docker images$undefined/year
    • Covered by the VerneMQ EULA, not Apache 2.0
    • Yearly usage subscription expected for commercial use
    • Official builds and Docker images
  • Commercial support$undefined/year
    • Evaluation, customisation and operations assistance
    • Custom development
    • Long-term maintenance agreements

Which should you pick?

Choose Longhorn if

  • You need per-volume controllers.
  • You want to start without paying.
  • You work on Linux, Kubernetes.
  • You also want synchronous replication.
Longhorn review

Choose VerneMQ if

  • You need erlang/otp clustering.
  • You want to start without paying.
  • You work on Linux, Docker, macOS, Kubernetes.
  • You also want mqtt 5.0 support.
VerneMQ review

Questions people ask

Is Longhorn or VerneMQ better?
Neither clearly leads. Longhorn starts at Free and VerneMQ at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Longhorn or VerneMQ?
Longhorn starts at Free and VerneMQ at Free.
Does Longhorn or VerneMQ run on more platforms?
Longhorn runs on Linux, Kubernetes. VerneMQ runs on Linux, Docker, macOS, Kubernetes.
Can I use Longhorn for free?
Both have a free tier, so you can try either at no cost before committing.
What is Longhorn best used for?
Longhorn is most often used for an on-premises kubernetes cluster with local disks and no san that needs replicated persistent volumes, edge sites where shipping a storage array is impractical and three nodes is the whole cluster, a k3s deployment where the storage layer must be light enough to run alongside the workloads, a team that wants snapshots and s3 backups of persistent volumes without paying per-node storage licences. Of those, an on-premises kubernetes cluster with local disks and no san that needs replicated persistent volumes and edge sites where shipping a storage array is impractical and three nodes is the whole cluster are not what VerneMQ is typically brought in for.
What can Longhorn do that VerneMQ cannot?
Longhorn covers Per-volume controllers, Synchronous replication, Snapshots and backups, Volume expansion. VerneMQ covers Erlang/OTP clustering, MQTT 5.0 support, Plugin system, Backpressure handling.

Answered from the vendors’ own pages

Longhorn: Who do we call when it breaks?

Nobody, unless you buy SUSE Rancher Prime, which includes commercial support for Longhorn. This is the decisive question for production use.

VerneMQ: Is VerneMQ free?

The source is Apache 2.0 and free. The official binary packages and Docker images are covered by a separate EULA that expects a yearly fee for commercial use.

Longhorn: How much capacity does replication cost?

Full copies, so three replicas means three times the raw capacity. Budget accordingly rather than assuming erasure coding efficiency.

VerneMQ: Is the project still maintained?

Yes. Octavo Labs AG in Zurich continues to publish 2.x releases, most recently in 2026.

Longhorn: Is it suitable for production databases?

For modest workloads yes, but synchronous replication adds write latency and high-transaction databases usually want something faster.

VerneMQ: Does it have a managed cloud?

No. Every deployment is self-hosted, with commercial support available from Octavo Labs.

VerneMQ: How does it compare to EMQX?

Narrower in features and without a rule engine, but with a simpler licence story for source builds after EMQX moved to BSL.

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