This script is used to start mst service and to stop it. It is also used in other operations with NVIDIA® devices, such as in resetting or enabling remote access.


mst <command> [switches] 

mst Commands and Switches Description - Linux

mst start [--with_msix] [-- with_unknown] [--with_i2cdev] [-- with_lpcdev] [--with_fpga] [-- with_fpga_fw_access

Create special files that represent NVIDIA® devices in directory /dev/mst. Load appropriate kernel modules and saves PCI configuration headers in directory /var/mst_pci. After successfully completion of this command the MST driver is ready to work. You can configure the start command by editing the configuration file: /etc/mft/mst.conf, for example you can rename you devices.


  • --with_msix: Create the msix device.

  • --with_unknown: Do not check if the device ID is supported.

  • --with_i2cdev: Create Embedded I2C master

  • --with_fpga: Create MST device for the attached FPGA card (Access via Driver)

  • --with_fpga_fw_access: Create an extended MST device for the attached FPGA (Access via Firmware)

mst stop [--force]

Stop the MST driver service, remove all special files/ directories and unload kernel modules.


  • --force: Force try to stop mst driver even if it's in use.

mst restart [--with_msix] [-- with_unknown] [--with_i2cdev] [--with_lpcdev] [--with_fpga] [--with_fpga_fw_access]

Just like "mst stop" followed by "mst start [--with_msix] [--with_unknown] [--with_i2cdev] [--with_lpcdev] [-- with_fpga] [--with_fpga_fw_access]"

mst server start [port]

Start mst server to allow incoming connection. Default port is 23108

mst server stop

Stop mst server.

mst remote add <hostname>[:port]

Establish connection with specified host on specified port (default port is 23108). Add devices on remote peer to local devices list. <hostname> may be host name as well as an IP address.

mst remote del <hostname>[:port]

Remove all remote devices on specified hostname.

<hostname>[:port] should be specified exactly as in the "mst remote add" command.

mst ib add [OPTIONS] [local_hca_id] [local_hca_port]

Add devices found in the IB fabric for inband access. Requires OFED installation and an active IB link.

If local_hca_id and local_hca_port are given, the IB subnet connected

to the given port is scanned. Otherwise, the default subnet is scanned.


  • --discover-tool <discover-tool>: The tool that is used to discover the fabric.

Supported tools: ibnetdiscover, ibdiagnet. default: ibdiagnet

  • --add-non-mlnx: Add non NVIDIA® nodes.

  • --topo-file <topology-file>: A prepared topology file which describes the fabric. For ibnetdiscover: provide an output of the tool. For ibdiagnet: provide LST file that ibdiagnet generates.

  • --use-ibdr: Access by direct route MADs. Available only when using ibnetdiscover tool, for SwitchX and ConnectIB devices.

NOTE: If a topology file is specified, device are taken from it. Otherwise, a discover tool is run to discover the fabric.

mst ib del

Remove all inband devices.

mst cable add [OPTIONS] [params]

Add the cables that are connected to 5th generation devices.

There is an option to add the cables found in the IB fabric for Cable Info access, requires WinOF-2 installation and active IB links. If local_hca_id and local_hca_port are given, the IB subnet connected to the given port is scanned. Otherwise, all the devices will be scanned.


--with_ib: Add the inband cables in addition to the local PCI devices.

params: [local_hca_id] [local_hca_port]

mst cable del

Remove all cable devices.

mst status

Print current status of NVIDIA® devices


  • -v run with high verbosity level (print more info on each device)

mst save

Save PCI configuration headers in directory /var/mst_pci.

mst load

Load PCI configuration headers from directory /var/mst_pci.

mst version

Print the version info

Edit the /etc/mft/mst.conf configuration file to configure the start operation in Linux (only).

The configuration file consists of lines of rules. Every line will be a rule for mst start. It must be valid, and the rules should be unique. There should also be no duplication of new names and/or serials.

The rule general format is the following:


mst start Supported OPCODES





renames mst devices

  • Rule format: RENAME $TYPE $NEW_NAME $ID

  • Supported types: # MTUSB (where $ID is the iSerial)

  • Example: RENAME USB my 0x2A4C.

  • Effect: MTUSB with serial 0x2A4C will be renamed to /dev/mst/mymtusb-1 (always mtusb-1 will be concatenated to the new name).

To start the mst driver service:


# mst start Starting MST (Mellanox Software Tools) driver set Loading MST PCI module - Success Loading MST PCI configuration module - Success Create devices MTUSB-1 USB to I2C Bridge - Success

To stop the service:


Success# mst stop Stopping MST (Mellanox Software Tools) driver set Unloading MST PCI module - Success

To print the current status of NVIDIA® devices:


Success# mst status MST modules: ------------ MST PCI module loaded MST PCI configuration module loaded   MST devices: ------------ /dev/mst/mt4099_pciconf0 - PCI configuration cycles access. domain:bus:dev.fn=0000:0b:00.0 addr.reg=88 data.reg=92 Chip revision is: 01 /dev/mst/mt4099_pci_cr0 - PCI direct access. domain:bus:dev.fn=0000:0b:00.0 bar=0xd2600000 size=0x100000 Chip revision is: 01 /dev/mst/mtusb-1 - USB to I2C adapter as I2C master iSerial = 0x1683

To show the devices status with detailed information


# mst status -v PCI devices: DEVICE_TYPE MST PCI RDMA NET NUMA ConnectX4(rev:0) /dev/mst/mt4115_pciconf0 08:00.0 mlx5_0 net-ib2 -1 ConnectX4(rev:0) /dev/mst/mt4115_pciconf0.1 08:00.1 mlx5_1 net-ib3 -1 ConnectIB(rev:0) /dev/mst/mt4113_pciconf0 0b:00.0 mlx5_2 net-ib4, net-ib5 -1 ConnectX3(rev:1) /dev/mst/mt4099_pciconf0 ConnectX3(rev:1) /dev/mst/mt4099_pci_cr0 0e:00.0 mlx4_0 net-ib0, net-ib1 -1 I2C devices: ------------------- MST Serial /dev/mst/mtusb-1 0x1B5C

In case the device has Function Per Port (FPP) enabled on it, a new device will appear in the `mst status -v` output with information about the second physical function. Example:


DEVICE_TYPE MST PCI RDMA NET NUMA ConnectX4(rev:0) /dev/mst/mt4115_pciconf0 07:00.0 mlx5_4 net-ib4 -1 ConnectX4(rev:0) /dev/mst/mt4115_pciconf0.1 07:00.1 mlx5_5 net-ib5 -1

© Copyright 2023, NVIDIA. Last updated on May 23, 2023.