# Vast.ai on-demand, reserved and interruptible instances

Compare Vast.ai rental types using priority, prepayment, instance-bound credits and restartable work rather than headline rate differences alone.

Author: Retrivium team
Updated: 2026-11-01
Canonical URL: https://retrivium.ai/journal/vast-ai-reserved-interruptible-choice/
Language: en

Vast.ai on-demand and reserved instances have high priority, while interruptible instances may pause when higher-priority demand takes over. Reserved pricing is obtained by converting an on-demand instance with prepayment. Choose from the workload's tolerance for delay and the expected operating period.

## Compare the actual mechanisms

The type documentation describes switching between on-demand and interruptible as requiring a new instance. Do not plan that transition as an in-place toggle for an existing working environment.

| Mode | Mechanism | Main project check |
| --- | --- | --- |
| On-demand | High priority under the host offer | Maximum rental duration |
| Reserved | On-demand with prepaid discount | Credits tied to the specific instance |
| Interruptible | Bid priority and possible pauses | Saved progress and reliable continuation |

This compares product behaviour, not measured uptime. A high-priority listing still needs workload compatibility, data preservation and an appropriate rental window.

## Decide whether a pause is acceptable

Independent document jobs can record completed items and continue later. A demonstration at a fixed time may not tolerate waiting. The same GPU can therefore call for a different rental type in these two situations.

Identify where progress is stored. Retained files and the state of a running process are different. If continuation depends on variables still held only in memory, a preserved disk does not establish resilience. Test the application's restoration path explicitly.

## Include repeated work in the pilot

For a thousand independent images, write results by input identifier and keep a completion journal. Interrupt a small controlled run and verify that it resumes without silently duplicating finished work.

Only then compare the full interruptible experiment with an alternative. Include environment loading, lost work, transfer and waiting. The difference between published compute rates is not necessarily the project's net saving, since recovery depends on the application's design.

## Inspect a reservation before committing

Check prepayment duration, instance-bound credits and the current early-cancellation rules. Do not transfer the meaning of reserved from another cloud's product. A short pilot on the intended configuration should establish RAM, disk, network and model compatibility first.

Consider whether requirements may change soon. If the team will need another host or resource size, the commitment's binding matters. Preserve a decision record with tolerated downtime, recovery method and horizon. Revisit it if interactive response requirements replace a previously flexible batch schedule.

## Turn the check into a practical next step

Choose rental type from interruption tolerance and a verified recovery procedure. An advertised rate difference is not automatically a saving on the complete task.

For the documented details, consult the [primary documentation](https://docs.vast.ai/guides/instances/choosing/instance-types); [configuration reference](https://docs.vast.ai/guides/instances/choosing/reserved-instances). Continue with [vast ai instance lifecycle stop destroy](/journal/vast-ai-instance-lifecycle-stop-destroy/) and [vast ai storage network charges](/journal/vast-ai-storage-network-charges/).