SHMTOTAL configuration parameter
Use the SHMTOTAL configuration parameter to specify the
total amount of shared memory (resident, virtual, communications,
and virtual extension portions) to be used by the database server
for all memory allocations. The onconfig.std value
of 0
implies that no limit on memory allocation is
stipulated.
- onconfig.std value
- SHMTOTAL 0
- values
0
= (no specific limit) or any integer greater than or equal to 1- units
- Kilobytes
- takes effect
-
- After you edit your onconfig file and restart the database server.
- When you reset the value dynamically in your onconfig file by running the onmode -wf command.
- When you reset the value in memory by running the onmode -wm command.
Usage
size of resident + virtual segments xx + yy > zz total allowed by
configuration parameter SHMTOTAL
- Value
- Description
- xx
- Current size of resident segments
- yy
- Current size of virtual segments
- zz
- Total shared memory required
If you enabled the LOW_MEMORY_MGR configuration parameter and are configuring the server to use a percentage of the SHMTOTAL configuration parameter value for automatic low memory management start and stop thresholds, the SHMTOTAL configuration parameter must not be set to 0 (unilmited).
Set the operating-system parameters for maximum shared-memory segment size, typically SHMMAX, SHMSIZE, or SHMALL, to the total size that your database server configuration requires. For information about the amount of shared memory that your operating system allows, see the machine notes.
If you have more physical memory than the value specified in the machine notes, and the memory is to be used by IBM® Informix®, you can increase the value of the SHMALL parameter to as much 90 percent of the physical memory that is specified for your computer. It is recommended that you do not meet or exceed the available RAM.