Explanation:
On Domino 6.x and 7.x systems where the physical RAM is greater than 2 GB, Domino 6.x and 7.x servers will calculate the maximum size of the Unified Buffer Manager (UBM) at 3/8 of the physical RAM. This can be problematic on UNIX systems in particular. The UBM can reach a size of up to 1.5 GB (assuming 4GB of physical RAM) which can cause failures when the UBM combined with other Domino shared memory components exceed per-process memory usage maximums..
Note - this is the same setting as NSF_BUFFER_POOL_SIZE_MB, except that the buffer pool size is specified in bytes rather than megabytes.
Default:
For Domino 8 and later running on 32 bit systems, the default Maximum UBM size is 524288 bytes (for most operating systems; 409600 bytes for z/OS and zLinux.)
For Domino 8 running on 64 bit systems the default Maximum UBM size is 1048576 bytes (for most operating systems; no default maximum for z/OS and zLinux)
For Domino 8.5 running on 64 bit systems, the default Maximum UBM size is 1048576 bytes (for most operating systems including zLinux; no default maximum for z/OS)
For Domino 7.x and earlier, when this value is not manually overridden, it's calculated as a percentage of available physical memory.
Domino 7.0.4 for OS390 & zLinux the value is hard coded to 409600 bytes
Domino 7.0.4 for all other operating systems, the calculation is:
1/8 of the first 32 MB, 1/4 of the next 96 MB, and 3/8 of everything beyond that.
Recommendation:
- Domino 8 servers - no action is needed. By default a maximum UBM size of 524288 bytes is enforced. Notes.ini settings specifying a larger size will be honored if present.
- Domino 6.x and 7.x servers, bring down the Domino server. Set NSF_BUFFER_POOL_SIZE using the table below as a guide. Restart the Domino server.
Operating system | Recommended UBM Maximum (Domino 32-bit) |
Windows32 | 536870912 bytes - 786432000 bytes |
Linux | 536870912 bytes - 786432000 bytes |
AIX | 536870912 bytes - 786432000 bytes |
Solaris | 536870912 bytes - 786432000 bytes |
i5/OS | 536870912 bytes - 786432000 bytes |
z/OS & zLinux | 209715200 bytes - 419430400 bytes |
Restrictions:
This is available for all Domino server versions.
Restarts:
The Domino server must be restarted after modifying this setting.
References:
Recommendations for setting NSF_BUFFER_POOL_SIZE_MB
New default limit on UBM size in Domino 8
Domino Configuration Tuner:
This setting is included in the
DCT catalog of best practices.