Update disk settings such as description, power management, SMART monitoring, and standby configuration.
AI agents use disk_update 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 disk configuration settings (description, power management, SMART monitoring, standby) which are system parameters that can be changed and reverted. It does not delete data or perform irreversible operations, nor does it execute arbitrary commands or involve financial transactions.
From the tool's definition Tool name 'disk_update' and description explicitly states it updates disk settings: 'description, power management, SMART monitoring, and standby configuration.' This is a reversible modification of disk configuration parameters.
Documented attack patterns abuse exactly the kind of access disk_update 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 disk_update:
{
"version": "1",
"default": "deny",
"tools": {
"disk_update": {
"limits": [
{
"counter": "disk_update_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}disk_update 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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Update disk settings such as description, power management, SMART monitoring, and standby configuration. 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 disk_update: 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.
disk_update 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 disk_update 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 disk_update. 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.
disk_update 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.