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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 Synopsis - Linux

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 delRemove 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 delRemove all cable devices.
mst status

Print current status of NVIDIA® devices


  • -v run with high verbosity level (print more info on each device)
mst saveSave PCI configuration headers in directory /var/mst_pci.
mst loadLoad PCI configuration headers from directory /var/mst_pci.
mst versionPrint the version info

Using mst.conf File in Linux

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).

Examples of mst Usage - Linux

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