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NVIDIA UFM-SDN Appliance User Manual v4.18.4

UFM Subnet Manager Default Properties

The following table provides a comprehensive list of UFM SM default properties.

Category

Property

Config File Attribute

Default

Mode/ Field

Description

Keys

M_Key

m_key

0x0000000000000000

RW

M_Key value sent to all ports -used to qualify the set(PortInfo)

M_Key Lease Period

m_key_lease_period

0

RW

The lease period used for the M_Key on the subnet in [sec]

SM_Key

sm_key

0x0000000000000001

RO

SM_Key value of the SM used for SM authentication

SA_Key

sa_key

0x0000000000000001

RO

SM_Key value to qualify rcv SA queries as 'trusted'

Subnet Prefix

subnet_prefix

0xfe80000000000000

RW

Subnet prefix used on the subnet 0xfe80000000000000

LMC

lmc

0

RW

The LMC value used on the subnet: 0-7

Changes to the LMC parameter require a UFM restart

Partition enforcement

part_enforce

  • Out

  • In

  • Both (default- outbound and inbound enforcement enabled)

RO

Partition enforcement type (for switches)

MKEY lookup

m_key_lookup

FALSE

RW

If FALSE, SM will not try to determine the m_key of unknown ports

Limits

Packet Life Time

packet_life_time

0x12

RW

The maximum lifetime of a packet in a switch.

The actual time is 4.096usec * 2^<packet_life_time>

The value 0x14 disables the mechanism

VL Stall Count

vl_stall_count

0x07

RO

The number of sequential packets dropped that cause the port to enter the VL Stalled state. The result of setting the count to zero is undefined

Leaf VL Stall Count

leaf_vl_stall_count

0x07

RO

The number of sequential packets dropped that causes the port to enter theleaf VL Stalled state. The count is for switch ports driving a CA or gateway port. The result of setting the count to zero is undefined

Head Of Queue Life time

head_of_queue_lifetime

0x12

RW

The maximum time a packet can wait at the head of the transmission queue. The actual time is 4.096usec * 2^<head_of_queue_lifetime>

The value 0x14 disables the mechanism

Leaf Head Of Queue Life time

leaf_head_of_queue_lifetime

0x10

RW

The maximum time a packet can wait at the head of queue on a switch port connected to a CA or gateway port

Maximal Operational VL

max_op_vls

3

RW

Limit of the maximum operational VLs

Force Link Speed

force_link_speed

15

(Do NOT change)

RO

Force PortInfo: LinkSpeedEnabled on switch ports.

If 0, do not modify.

Values are:

1: 2.5 Gbps

3: 2.5 or 5.0 Gbps

5: 2.5 or 10.0 Gbps

7: 2.5 or 5.0 or 10.0 Gbps

2,4,6,8-14 Reserved

15: set to PortInfo: LinkSpeedSupported

For a fabric with DDR 10 Gb Ethernet Gateways (sRB-20210G) and 4036E version lower than 3.7.0.896, this parameter should be set to None (0) - auto negotiate link speed according to INI settings

Subnet Timeout

subnet_timeout

18 (1second)

RW

The subnet_timeout code that will be set for all the ports.

The actual timeout is 4.096usec * 2^<subnet_timeout>

Local PHY Error Threshold

local_phy_errors_threshold

0x08

RW

Threshold of local phy errors for sending Trap 129

Overrun Errors Threshold

overrun_errors_threshold

0x08

RW

Threshold of credit overrun errors for sending Trap 130

Sweep

Sweep Interval

sweep_interval

10

RW

The time in seconds between subnet sweeps (Disabled if 0)

Reassign Lids

reassign_lids

FALSE (disabled)

RW

If TRUE (enabled), all LIDs are reassigned

Force Heavy Sweep

force_heavy_sweep_window

-1

RW

Forces heavy sweep after number of light sweeps

(-1 disables this option and 0 will cause every sweep to be heavy)

Sweep On trap

sweep_on_trap

TRUE (enabled)

RW

If TRUE every trap will cause a heavy sweep

Alternative Route Calculation

max_alt_dr_path_retries

4

RW

Maximum number of attempts to find an alternative direct route towards unresponsive ports

Fabric Rediscovery

max_seq_redisc

2

RW

Max Failed Sequential Discovery Loops

Handover

SM Priority

sm_priority

15

RO

SM (enabled). The priority used for deciding which is the master. Range is 0 (lowest priority) to 15 (highest)

Ignore Other SMs

ignore_other_sm

FALSE (disabled)

RO

If TRUE other SMs on the subnet should be ignored

Polling Timeout

sminfo_polling_timeout

10

RO

Timeout in seconds between two active master SM polls

Polling Retries

polling_retry_number

4

RO

Number of failing remote SM polls that declares it non-operational

Honor GUID-to-LID File

honor_guid2lid_file

FALSE

(disabled)

RO

If TRUE, honor the guid2lid file when coming out of standby state, if the guid2lid file exists and is valid

Threading

Max Wire SMPs

max_wire_smps

8

RW

Maximum number of SMPs sent in parallel

Transaction Timeout

transaction_timeout

200

RO

The maximum time in [msec] allowed for a transaction to complete

Max Message FIFO Timeout

max_msg_fifo_timeout

10000

RO

Maximum time in [msec] a message can stay in the incoming message queue

Single Thread

single_thread

FALSE

(disabled)

RO

Use a single thread for handling SA queries

Routing Threads

routing_threads_num

0

RW

Number of threads to be used for parallel minhop/updn calculations.

If 0, number of threads will be equal to number of processors

Routing Threads Per Core

max_threads_per_core

0

RW

Max number of threads that are allowed to run on the same processor during parallel computing.

If 0, threads assignment per processor is up to operating system initial assignment

Logging

Log File

log_file

/opt/ufm/files/log/opensm.log

RO

Path of Log file to be used

Log Flags

log_flags

Error and Info

0x03

RW

The log flags, or debug level being used

Force Log Flush

force_log_flush

FALSE

(disabled)

RO

Force flush of the log file after each log message

Log Max Size

log_max_size

4096

RW

Limit the size of the log file in MB. If overrun, log is restarted

Accumulate Log File

accum_log_file

TRUE

(enabled)

RO

If TRUE, will accumulate the log over multiple OpenSM sessions

Dump Files Directory

dump_files_dir

/opt/ufm/files/log

RO

The directory to hold the file SM dumps (for multicast forwarding tables for example). The file is used collects information

Syslog log

syslog_log

0x0

RW

Sets a verbosity of messages to be printed in syslog

Misc

Node Names Map File

node_name_map_name

Null

RW

Node name map for mapping node's to more descriptive node descriptions

SA database File

sa_db_file

Null

RO

SA database file name

No Clients Reregistration

no_clients_rereg

FALSE

(disabled)

RO

If TRUE, disables client re-registration

Exit On Fatal Event

exit_on_fatal

TRUE

(enabled)

RO

If TRUE (enabled), the SM exits for fatal initialization issues

Switch Isolation From Routing

held_back_sw_file

null

RW

File that contains GUIDs of switches isolated from routing

Multicast

Disable Multicast

disable_multicast

FALSE

(disabled)

RO

If TRUE, OpenSM should disable multicast support and no multicast routing is performed

Multicast Group Parameters

default_mcg_mtu

0

RW

Default MC group MTU for dynamic group creation. 0 disables this feature, otherwise, the value is a valid IB encoded MTU

Multicast Group Parameters

default_mcg_rate

0

RW

Default MC group rate for dynamic group creation. 0 disables this feature, otherwise, the value is a valid IB encoded rate

Enable incremental multicast routing

enable_inc_mc_routing

FALSE

RW

Enable incremental multcast routing

MC root file

mc_roots_file

null

RW

Specify predefined MC groups root guids

QoS

Settings

qos

FALSE

(disabled)

*From UFM v3.7 and on

RW

If FALSE (disabled), UFM will not apply QoS settings

Unhealthy Ports

Enabling Unhealthy Ports

hm_unhealthy_ports_checks

TRUE

RW

Enables Unhealthy Ports configuration

Configuration file

hm_ports_health_policy_file

null

RW

Specifies configuration file for health policy

Unhealthy actions

hm_sw_manual_action

no_discover

RW

Specifies what to do with switch ports which were manually added to health policy file

MADs validation

validate_smp

TRUE

RW

If set to TRUE, opensm will ignore nodes sending non-spec compliant MADs. When set to FALSE, opensm will log the warning in the opensm log file about non-compliant node

Routing

Randomization

scatter_ports

8

RW

Assigns ports in a random order instead of round-robin. If 0, the feature is disabled, otherwise use the value as a random seed.

Applicable to the MINHOP/UPDN routing algorithms

Randomization

guid_routing_order_no_scatter

TRUE

RO

Do not use scatter for ports defined in guid_routing_order file

Unicast Routing Caching

use_ucast_cache

TRUE

RW

Use unicast routing cache for routing computation time improvement

GUID Ordering During Routing

guid_routing_order_file

NULL

RW

The file holding guid routing order of particular guids (for MinHop, Up/Down)

Torus Routing

torus_config

/opt/ufm/files/conf/opensm/torus-2QoS.conf

RW

Torus-2QoS configuration file name

Routing Chains

pgrp_policy_file

NULL

RW

The file holding the port groups policy

topo_policy_file

NULL

RW

The file holding the topology policy

rch_policy_file

NULL

RW

The file holding the routing chains policy

max_topologies_per_sw

1

RO

Defines maximal number of topologies to which a single switch may be assigned during routing engine chain configuration

Incremental Multicast Routing (IMR)

enable_inc_mc_routing

TRUE

RW

If TRUE, MC nodes will be added to the MC tree incrementally. When set to FALSE, the tree will be recalculated per each change

MC Global root

mc_primary_root_guid/mc_secondary_root_guid

0x0000000000000000 (for both)

RW

Primary and Secondary global mc root guid

Scatter ports

use_scatter_for_switch_lid

FALSE

RW

Use scatter when routing to the switch’s LIDs

Events

Event Subscription Handling

drop_subscr_on_report_fail

FALSE

RW

Drop subscription on report failure (o13-17.2.1)

Event Subscription Handling

drop_event_subscriptions

TRUE

RW

Drop event subscriptions (InformInfo and ServiceRecords) on port removal and SM coming out of STANDBY

Virtualization

Virtualization enabled

virt_enabled

0 (Ignored)

RW

Enables/disables virtualization support

Maximum ports in virtualization process

virt_max_ports_in_process

4

RW

Sets a number of ports to be handled on each virtualization process cycle

© Copyright 2025, NVIDIA. Last updated on Jul 3, 2025.