Short Description: Used to control shared memory on Domino/AIX
|When using ConstrainedSHMSizeMB it is possible to incorrectly set the value to something that is not divisible by 256 MB. Setting ConstrainedSHMSizeMB incorrectly could reduce the amount of shared memory used by the entire Lotus® Domino® instance.
On AIX® Domino instances, shared memory must be controlled when it is necessary to ensure access to a specific amount of shared memory. A third-party Domino API would be a typical reason for controlling the amount of shared memory.
|This issue has been fixed in Domino 7.0.2 Fix Pack 1 (FP1) and 7.0.3.
Excerpt from the Lotus Domino fix list (available at http://www.ibm.com/developerworks/lotus):
SPR# XJXJ6RW8VF - The Notes.ini variable AixLimitShmSegments, is to be used in place of the Notes.ini variable ConstrainedSHMSizeMB to ensure entire segments are specified for shared memory. The lower limit is 3 and the current upper limit is 10. The maximum number of shared memory segments when using the AIX Large Memory Model is 8. The maximum number of shared memory segments when using the AIX Very Large Memory Model is 10. Future releases of Domino may allow for a maximum of 11 shared memory segments.
Refer to the Upgrade Central site for details on upgrading Notes/Domino.
By setting AIX_LIMIT_SHM_SEGMENTS, the Domino instance will have access to shared memory on a whole segment basis. One memory segment on AIX has the maximum value of 256 Meg.
The lower segment limit is 3 and the current upper segment limit is 10 for AIX_LIMIT_SHM_SEGMENTS.
To have access to the full 10 segments of shared memory, for use with AIX_LIMIT_SHM_SEGMENTS, it is necessary to set AIX_VERY_LARGE_MM=1.
AIX_VERY_LARGE_MM requires Domino 7.0.2, AIX 5L version 5.2 or later, running the AIX 64 bit kernel.
Without setting AIX_VERY_LARGE_MM, the upper limit for AIX_LIMIT_SHM_SEGMENTS is 8.
An example setting of AIX_LIMIT_SHM_SEGMENTS=5 would provide 5 256 Meg segments or 1280 Meg of shared memory.
As with ConstrainedSHMSizeMB, setting AIX_LIMIT_SHM_SEGMENTS, too high will result in limiting the number of segments for process memory.
There is no kown UI setting for this notes.ini variable. But you can specify this setting in the notes.ini settings tab of the configuration settings document.