Promote a cloned dataset to no longer depend on its origin snapshot
AI agents use dataset_promote to create or update resources in Truenas — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Truenas environment.
This tool modifies dataset metadata and storage relationships irreversibly by severing snapshot dependencies. While it doesn't delete data or move money, promoting a dataset can have significant storage management consequences (e.g., preventing snapshot deletion, changing data lifecycle). It's Write rather than Destructive because the operation itself doesn't erase data—it reconfigures relationships.
From the tool's definition Tool performs 'promote' operation on a cloned dataset, which modifies the dataset's dependency structure and metadata.
Documented attack patterns abuse exactly the kind of access dataset_promote gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Truenas, and nothing reaches the server without passing your rules. This is the rule we recommend for dataset_promote:
{
"version": "1",
"default": "deny",
"tools": {
"dataset_promote": {
"limits": [
{
"counter": "dataset_promote_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}dataset_promote stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
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Promote a cloned dataset to no longer depend on its origin snapshot. It is categorised as a Write tool in the Truenas MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Truenas MCP server in PolicyLayer and add a rule for dataset_promote: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Truenas. Nothing to install.
dataset_promote is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the dataset_promote rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for dataset_promote. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
dataset_promote is provided by the Truenas MCP server (spranab/truenas-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Truenas, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
279 Truenas tools catalogued and risk-classified — across an index of 43,000+ MCP servers.