User Manual

InfiniBand Fabric UtilitiesRev 2.3-1.0.1
Mellanox Technologies
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4.4.1 Link Level Retransmission (LLR) in FDR Links
With the introduction of FDR 56 Gbps technology, Mellanox enabled a proprietary technology
called LLR (Link Level Retransmission) to improve the reliability of FDR links.
This proprietary LLR technology adds additional CRC checking to the data stream and retrans-
mits portions of packets with CRC errors at the local link level. Customers should be aware of
the following facts associated with LLR technology:
• Traditional methods of checking the link health can be masked because the LLR tech-
nology automatically fixes errors. The traditional IB symbol error counter will show no
errors when LLR is active.
• Latency of the fabric can be impacted slightly due to LLR retransmissions. Traditional
IB performance utilities can be used to monitor any latency impact.
mstflint Queries and burns a binary firmware-image file on non-volatile (Flash) mem-
ories of Mellanox InfiniBand and Ethernet network adapters. The tool
requires root privileges for Flash access.
To run mstflint, you must know the device location on the PCI bus.
Note: If you purchased a standard Mellanox Technologies network adapter
card, please download the firmware image from
www.mellanox.com > Sup-
port > Firmware Download. If you purchased a non-standard card from a
vendor other than Mellanox Technologies, please contact your vendor.
For further information, please refer to the tool’s man page.
perfquery Queries InfiniBand ports’ performance and error counters. Optionally, it dis-
plays aggregated counters for all ports of a node. It can also reset counters
after reading them or simply reset them.
For further information, please refer to the tool’s man page.
saquery Issues the selected SA query. Node records are queried by default.
For further information, please refer to the tool’s man page.
sminfo Issues and dumps the output of an sminfo query in human readable format.
The target SM is the one listed in the local port info or the SM specified by the
optional SM LID or by the SM direct routed path.
Note: Using sminfo for any purpose other than a simple query might result in
a malfunction of the target SM.
For further information, please refer to the tool’s man page.
smparquery Sends SMP query for adaptive routing and private LFT features.
For further information, please refer to the tool’s man page.
smpdump A general purpose SMP utility which gets SM attributes from a specified
SMA. The result is dumped in hex by default.
For further information, please refer to the tool’s man page.
smpquery Provides a basic subset of standard SMP queries to query Subnet management
attributes such as node info, node description, switch info, and port info.
For further information, please refer to the tool’s man page.
Table 7 - Diagnostic Utilities (Sheet 6 of 6)
Utility Description