Configuring INT_LOG_MAX_PAYLOAD_SIZE Parameter

Describes the configuration of the Mellanox device firmware parameter INT_LOG_MAX_PAYLOAD_SIZE, on IBM Storage Scale NSD Servers, Protocol nodes, and clients.

Run the command shown to view the current settings of INT_LOG_MAX_PAYLOAD_SIZE on all Mellanox devices on the system.

for i in `ls /sys/class/infiniband/`; do mlxconfig -d $i -e q INT_LOG_MAX_PAYLOAD_SIZE; done

Note: You need to install the mlxconfig tool. For more information, see Mellanox Firmware Tools User Manual.

The details of the command output are displayed in the tables shown.

Table 1. Device details for Device 1
Device Type	Name	Description	Device
ConnectX5	00WT174_Ax	PCIe4 2-port VPI EDR IB (100 Gb/s) and 100 GbE Adapter x16	mlx5_0

Table 2. Default Configurations for INT_LOG_MAX_PAYLOAD_SIZE
Configurations
INT_LOG_MAX_PAYLOAD_SIZE	AUTOMATIC(0)	AUTOMATIC(0)	AUTOMATIC(0)

INT_LOG_MAX_PAYLOAD_SIZE Settings

Setting 1: _4KB: 4 KB burst length (set by mlxconfig [...] INT_LOG_MAX_PAYLOAD_SIZE=12)

This is the non-default setting that is recommended for all IBM Storage Scale NSD servers and protocol nodes. It ensures the optimal performance, particularly for large I/O streaming use cases when RDMA is enabled.

Run the following command to configure _4KB(12) as the value for the INT_LOG_MAX_PAYLOAD_SIZE parameter of all Mellanox devices:

for i in `ls /sys/class/infiniband/`; do mlxconfig -d $i -e s INT_LOG_MAX_PAYLOAD_SIZE=12 ; done

The values that are displayed in the command output are shown in the following table.

Table 3. Recommended Configurations for INT_LOG_MAX_PAYLOAD_SIZE Values
Configuration	Default	Current	Next Boot
^*INT_LOG_MAX_PAYLOAD_SIZE	AUTOMATIC(0)	_4KB(12)	_4KB(12)
The * shows parameters with the next value that is different from the default or the current value.

Setting 2: AUTOMATIC: Default (set by mlxconfig [...] INT_LOG_MAX_PAYLOAD_SIZE=0)

The default setting is applicable to all IBM® Power® nodes that are not configured as an IBM Storage Scale server or protocol node. For example, compute nodes that are only clients of an IBM Storage Scale file system.

Run the following command to apply the default setting:

for i in `ls /sys/class/infiniband/`; do mlxconfig -d $i -e s INT_LOG_MAX_PAYLOAD_SIZE=0; done

Note: In both scenarios, after you run the commands, you need to restart your system for the changes to be effective.