iscsi_extent_update

Update an iSCSI extent (LUN)

SERVERTruenas SOURCEspranab/truenas-mcp

Medium RISK CLASS

Category Write

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/spranab-truenas-mcp/iscsi-extent-update.md

WHAT IT DOES

What iscsi_extent_update does on Truenas

AI agents use iscsi_extent_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.

RISK

Why iscsi_extent_update is rated Medium

This tool modifies iSCSI extent (Logical Unit Number) configurations, which are critical storage service components. Updates can alter disk allocations, access permissions, or performance settings for block storage targets. While not destructive (data is not deleted), misconfiguration could impact storage availability and data access for systems dependent on that iSCSI target.

From the tool's definition Update an iSCSI extent (LUN) - the verb 'update' indicates modification of an existing storage resource configuration

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs iscsi_extent_update safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Truenas, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For iscsi_extent_update, this is the rule to start with:

iscsi_extent_update Rate-limited

iscsi_extent_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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "iscsi_extent_update": {
      "limits": [
        {
          "counter": "iscsi_extent_update_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Truenas, apply this rule, and every iscsi_extent_update call is checked against it from then on.

FAQ

Questions about iscsi_extent_update

What does the iscsi_extent_update tool do? +

Update an iSCSI extent (LUN). 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.

How do I enforce a policy on iscsi_extent_update? +

Register the Truenas MCP server in PolicyLayer and add a rule for iscsi_extent_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.

What risk level is iscsi_extent_update? +

iscsi_extent_update is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit iscsi_extent_update? +

Yes. Add a rate_limit block to the iscsi_extent_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.

How do I block iscsi_extent_update completely? +

Set action: deny in the PolicyLayer policy for iscsi_extent_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.

What MCP server provides iscsi_extent_update? +

iscsi_extent_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.

KEEP EXPLORING

More on Truenas, and thousands of servers like it.

This server

All 279 Truenas tools →

Across the catalogue

aroflo_create_or_update_record on AroFlo MCP →team_manager_update_budget on Team Manager MCP → The MCP Attack Database →

Guides

Govern customer-ops agents →Argument validation →Scoped token →