buying guide
The Best Prometheus Long-Term Storage in 2026
Prometheus is single-node and short-memoried by design, so anything serious needs a long-term store bolted on. Here are the real options, ranked by the operational weight they add — because that, not features, is what you'll feel at 2am.
- 1 VictoriaMetrics Infra & metrics
The popular pick for a reason: cheapest and simplest, great compression, drop-in Prometheus-compatible. Start here unless you have a reason not to.
The catch: Strong on cost/compression, but it's a single-vendor project (not foundation-owned), and the most enterprise-attractive features (downsampling, multi-retention, anomaly detection) sit behind the Enterprise license despite the "fully open source" marketing.
- 2 Thanos Infra & metrics
The lowest-friction add-on if you already run Prometheus — a sidecar plus object storage. More moving parts than VictoriaMetrics, but minimal change to collection.
The catch: The sidecar-per-Prometheus model and many moving parts (store, compactor, querier, receiver) make it operationally fiddly, and query latency over object storage can disappoint.
- 3 Grafana Mimir Infra & metrics
Built for multi-tenant scale most people do not have. Reach for it when strict tenant isolation and huge cardinality are the actual problem.
The catch: Built for scale you probably don't have — the microservices (now Kafka-based in 3.0) are heavy to run, so for a handful of servers it's massive overkill vs VictoriaMetrics or plain Thanos.
- 4 GreptimeDB Infra & metrics
A newer unified TSDB (metrics + logs + traces) on object storage — promising if you want one store for everything and can tolerate a young project.
The catch: New and ambitious but young — the "one database for everything" promise is still maturing, tooling is thin vs incumbents, and it's a single-vendor bet.
- 5 Prometheus Infra & metrics
The baseline. For a homelab or a single small cluster, vanilla Prometheus with local storage may be all the "long-term" you actually need.
The catch: Single-node by design — no native HA or long-term storage — so any serious deployment becomes a 4-5 component stack (Alertmanager, Grafana, Thanos/Mimir, exporters) you assemble and operate yourself.
The long-term-storage options vs plain Prometheus
| VictoriaMetrics VictoriaMetrics Inc. | Thanos open source / community (CNCF) | Grafana Mimir Grafana Labs | Prometheus open source / community (CNCF) | |
|---|---|---|---|---|
| Category | Infra & metrics | Infra & metrics | Infra & metrics | Infra & metrics |
| License | Open core | Open source | Open source | Open source |
| Deployment | SaaS or self-hosted | Self-hosted | SaaS or self-hosted | Self-hosted |
| Monitors | MetricsServersK8sCloud | MetricsServersK8sCloud | MetricsServersK8sCloud | MetricsServersK8sCloudNetwork |
| Pricing | Free / OSSUsage credits Free tier ✓ | Free / OSS Free tier ✓ | Free / OSSUsage credits Free tier ✓ | Free / OSS Free tier ✓ |
| Cost | Low OSS free incl. clustering; Enterprise features + Cloud are paid. | Free | Free | Free Free software; cost is engineering time + the surrounding stack. |
| Self-host effort | Moderate | Heavy | Heavy | Heavy |
| Maturity | Rising | Established | Established | Incumbent |
| Protocols | PrometheusSNMP | |||
| The catch | Strong on cost/compression, but it's a single-vendor project (not foundation-owned), and the most enterprise-attractive features (downsampling, multi-retention, anomaly detection) sit behind the Enterprise license despite the "fully open source" marketing. | The sidecar-per-Prometheus model and many moving parts (store, compactor, querier, receiver) make it operationally fiddly, and query latency over object storage can disappoint. | Built for scale you probably don't have — the microservices (now Kafka-based in 3.0) are heavy to run, so for a handful of servers it's massive overkill vs VictoriaMetrics or plain Thanos. | Single-node by design — no native HA or long-term storage — so any serious deployment becomes a 4-5 component stack (Alertmanager, Grafana, Thanos/Mimir, exporters) you assemble and operate yourself. |
Built from the monitoring tool database — figures live there, not here.
FAQ
Does Prometheus have long-term storage built in?
Not really — local storage is meant for days-to-weeks of recent data on a single node, with no HA. For durable, queryable history you add a remote-storage back-end like VictoriaMetrics, Thanos or Mimir.
VictoriaMetrics vs Thanos vs Mimir — which should I pick?
VictoriaMetrics is the simplest and most cost-efficient, and the usual default. Thanos is the gentlest add-on if you want to keep your existing Prometheus servers and just bolt on object storage. Mimir is for large multi-tenant scale where its operational heft is justified.
No vendor wrote this, and nobody paid to be ranked. Browse the whole field in the monitoring tool database.