All Mellanox embedded SM's MTU is 2k(2048-4=2044).
Therefore you should change default partition's MTU to 4k(4096-4092).
Can you tell me if this will take effect immediately, or require a restart of the servers.
Will it cause an interruption of traffic?
Our IB is for traffic from Cluster nodes to SAN storage. I just want to know what the impact will be.
The error should clear once the SM's partition configuration (IpoIB MTU setting) is adjusted (to eliminate the inconsistency):
For example, to enable a 4096-byte IpoIB MTU on the Subnet Manager's default partition, (assuming SM is running on a switch), perform the following commands below. If more than one switch is running SM, this change should be made on each switch running SM.
In MLNX-OS, to change this MTU setting, the path to this setting is:
IB SM Mgt tab
In the existing Default Partition,
IPoIB MTU can be changed from 2K to 4K.
No other settinngs need to be changed.
Apply changes, but be aware that this is an intrusive configuration change and will disrupt the cluster as the SM process gets restarted and the MTU changes are applied.