Setting the number of devices on UNIX

If you are using a large number of devices on UNIX platforms, SAP recommends that you set the appropriate number of devices and user connections in the configuration file. Attempting to configure a large number of devices dynamically using sp_configure may fail.

The number of network connections and number of devices configuration parameters use operating system file descriptors. You must increase the number of operating system file descriptors to use a large value for either configuration parameter.

What constitutes a large number of devices is platform-specific. These are the upper limits for the number of file descriptors for SAP ASE:

HPIA 64, HPPA 64, AIX 64, Windows – Set by SAP ASE.
IBM RISC 64-bit – 2000
IBM PLinux – 2048
AMD64 Linux – 10000
IA32-bit Linux – 10000
IA 64-bit Linux – 1024

Note: Changing the number of file descriptors requires you restart SAP ASE for the change to take affect.

If there are insufficient number of file descriptors, SAP ASE issues an error message similar to:

Msg 5893, Level 16, State 1:Procedure 'sp_configure', Line 1234:
The sum, ( ((number of user connections) + (number of remote sites) + (max cisremote connections) + (number of java sockets)) / (max online engines)) + (number of devices ) + (max number network listeners), 
must be no greater than '958'.
Msg 5849, Level 16, State 1:Procedure 'sp_configure', Line 1234:
Verification failed for parameter 'number of devices'.
(return status = 1)

If you then set the number of file descriptors to 2048 with the command ulimit -n 2048 and restart the server, SAP ASE reports this message in the error log when you increase the value for the number of devices:

kernel Using 2048 file descriptors.