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Cloud · head to head

Longhorn vs Thanos

Longhorn logo

Longhorn

Cloud

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

From
Free
Rated
-
Full reviewWebsite
Thanos logo

Thanos

Cloud

Highly available Prometheus with long-term object storage

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.; Thanos several components — sidecar, store, querier, compactor, ruler — each with its own configuration and failure modes
  • They diverge on capability: Longhorn covers Per-volume controllers, Thanos covers Global query.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which Longhorn and Thanos actually diverge.

Attributes where Longhorn and Thanos differ
AttributeLonghornThanos
PlatformsLinux, KubernetesKubernetes, Linux, Docker

Identical on both: starting price (Free), pricing model (Open source, no licence fee), free tier (Yes), user rating (Not yet rated), category (Cloud).

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 Thanos

  • Global query
  • Object storage retention
  • Deduplication
  • Downsampling

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 Thanos
  • Edge sites where shipping a storage array is impractical and three nodes is the whole clusternot Thanos
  • A K3s deployment where the storage layer must be light enough to run alongside the workloadsnot Thanos
  • A team that wants snapshots and S3 backups of persistent volumes without paying per-node storage licencesnot Thanos

Thanos

  • Querying metrics across many clusters or regions from one placenot Longhorn
  • Retaining metrics for years without local disk growthnot Longhorn
  • Removing the gap that appears when a single Prometheus instance restartsnot 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.

Thanos

  • Several components — sidecar, store, querier, compactor, ruler — each with its own configuration and failure modes
  • The compactor is a common source of operational trouble and must not run twice against the same bucket
  • Query latency over object storage is meaningfully higher than local Prometheus
  • Object storage costs and API request charges become real at high volume

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

Thanos

Free
  • ThanosFree
    • Full functionality
    • No usage limits
    • Community support

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 Thanos if

  • You need global query.
  • You want to start without paying.
  • You work on Kubernetes, Linux, Docker.
  • You also want object storage retention.
Thanos review

Questions people ask

Is Longhorn or Thanos better?
Neither clearly leads. Longhorn starts at Free and Thanos at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Longhorn or Thanos?
Longhorn starts at Free and Thanos at Free.
Does Longhorn or Thanos run on more platforms?
Longhorn runs on Linux, Kubernetes. Thanos runs on Kubernetes, Linux, Docker.
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 Thanos is typically brought in for.
What can Longhorn do that Thanos cannot?
Longhorn covers Per-volume controllers, Synchronous replication, Snapshots and backups, Volume expansion. Thanos covers Global query, Object storage retention, Deduplication, Downsampling.

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.

Thanos: Is Thanos free?

Yes, open source and CNCF-incubating. Costs are the object storage it uses.

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.

Thanos: Does Thanos replace Prometheus?

No. It runs alongside existing Prometheus servers, adding global query, deduplication and long-term storage.

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.

Thanos: Thanos or VictoriaMetrics?

Thanos layers onto Prometheus using object storage and is the more established multi-cluster answer. VictoriaMetrics is a separate store aiming at lower resource use and fewer moving parts.

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