DB2 Version 9.7 for Linux, UNIX, and Windows
DB2 Version 9.7 for Linux, UNIX, and Windows
This topic outlines the recommended operating system user process resource limits (ulimits) on Linux® and UNIX® operating systems.
Depending on your installation, the DB2® engine automatically raises the ulimits to varying degrees:
In either case, it might be more practical to set the resource limits permanently on your system. Especially for non-root installations, the data, nofiles, and fsize ulimit values should be set appropriately by an administrator after installing.
After a non-root installation is completed, the instance owner should verify the hard operating system ulimits for the data, nofiles, and fsize resources. The recommended values are outlined in the following table:
| Hard ulimit resource | Description | Minimum value | Recommended value | Command to query the value |
|---|---|---|---|---|
| data | Maximum private memory allowed for a process | The amount of memory available on the computer | Unlimited | ulimit -Hd |
| nofiles | Maximum number of open files allowed for a process | Larger than the sum of all MAXFILOP database configuration parameters for all databases in the instance | 65536 or unlimited | ulimit -Hn |
| fsize | Maximum file size allowed | Unlimited | Unlimited | ulimit -Hf |
If the minimum ulimit values are not met, the DB2 engine could encounter unexpected operating system resource shortage errors. These errors can lead to a DB2 outage.
Contact a root user or a System Administrator if the ulimit values need to be updated for your non-root installation. Values for ulimits must be set manually, except on AIX® operating systems, where you also have the option to set ulimits by running the db2rfe command.
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