Performance

Tool Name: disks/performance

Retrieves granular block device I/O performance metrics (equivalent to iostat). Provides read/write sectors, merged operations, and I/O wait times in milliseconds. Use disks/list first to find valid block devices. If you want static capacity instead, use disks/free.

Example

Every example below shows the equivalent linuxctl command and the raw MCP JSON-RPC call it resolves to. The raw call always follows the same two-step pattern (see MCP API overview for the full explanation): open an SSE stream to get a one-time POST endpoint, then POST the JSON-RPC request there - the result streams back on the SSE connection.

linuxctl

linuxctl get disks performance vda

Output (Ubuntu 24.04 VPS):

Device       Reads        Writes       SectRead     SectWrite    I/O(ms)     
----------------------------------------------------------------------------
vda          18284        208946       1869176      5710280      26466       

curl (raw MCP JSON-RPC)

# 1. Open the SSE stream (in the background) and capture the one-time POST endpoint
curl -N -s --cacert mcpd.crt -H "Authorization: Bearer $MCP_TOKEN" https://localhost:9091/sse &
# server sends: event: endpoint / data: /message?session_id=...

# 2. POST the tools/call request to that endpoint
curl -s --cacert mcpd.crt -X POST "https://localhost:9091/message?session_id=<from step 1>" \
  -H "Authorization: Bearer $MCP_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc": "2.0", "id": "1", "method": "tools/call", "params": {"name": "disks/performance", "arguments": {"device": "vda"}}}'

# 3. The result arrives on the SSE stream opened in step 1

Response:

{
  "jsonrpc": "2.0",
  "id": "1",
  "result": {
    "content": [
      {
        "type": "text",
        "text": "Device       Reads        Writes       SectRead     SectWrite    I/O(ms)     \n----------------------------------------------------------------------------\nvda          18284        208946       1869176      5710280      26466       \n"
      }
    ]
  }
}

Example​

Example