Priority Value for sminfo and setsmpriority list shows different values

Asset ID:	1-71-2315815.1
Update Date:	2017-10-16
Keywords:

Solution Type Technical Instruction Sure

Solution 2315815.1 : Priority Value for sminfo and setsmpriority list shows different values

Applies to:

Sun Datacenter InfiniBand Switch 36 - Version All Versions to All Versions [Release All Releases]
Sun Network QDR InfiniBand Gateway Switch - Version All Versions to All Versions [Release All Releases]
Information in this document applies to any platform.

Goal

sminfo and setsmpriority list output shows different priority values

Solution

[root@ibswitch01 ~]# sminfo 1
sminfo: sm lid 1 sm guid 0x2128f5724ca0a0, activity count 149077576 priority 14 state 3 SMINFO_MASTER

[root@ibswitch01 ~]# setsmpriority list
Current SM settings:
smpriority 5
controlled_handover TRUE
subnet_prefix 0xfe80000000000000
M_Key None
Routing engine FatTree

The output of sminfo is the "effective priority" which is not the one set on that switch. In other words, what we see in the output of sminfo will not be the same as what is set on that switch when controlled handover is set to "TRUE". We never set SM priority to 14, when a switch with controlled handover set to TRUE becomes the master, it automatically sets its "effective priority" to 14 dynamically, even though the priority set on that is much lower. This is how it makes sure that the master never fails over to another switch until this switch fails.

[root@ibswitch01 ~]# setsmpriority list
Current SM settings:
smpriority 5
controlled_handover TRUE <<<<====================
subnet_prefix 0xfe80000000000000
M_Key None
Routing engine FatTree

The above behavior is by design and how it is intended to work when the controlled handover feature is enabled.

If you want the SM to honor the user configured priority value at all the times then you need to disable controlled handover. This feature is named 'handover-enabled' in the CLI. This might be a disruptive activity, it is recommended to perform any changes during maintenance window.

References

<BUG:19722643> - MASTER IS ALWAYS 14 IN SHOW DIAGNOSTICS OPENSM-PARAM AFTER CHANING PRIORITY

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