Tuning Local Systems When Using SNA Services with HCON

Prerequisites

1. The HCON program and messages must be installed on your system. For installation information, refer to the AIX Installation Guide.
2. SNA Services must be installed on your system.
3. You must have root authority to increase the following:
   • The number of processes allowed for each user
   • Available paging space
   • The default limits in the SNA Services server /dev/sna

Procedure

If a large number of SNA standalone sessions are run concurrently with HCON, your local system may require tuning to avoid problems associated with processor or memory utilization. Tune local systems, when using SNA services, using the following procedures.

Increase Allowable User Processes

To increase the number of allowable processes for each user, use the lsattr and chdev commands.

1. To determine the maximum number of processes allotted to a user, enter:

   lsattr -E -l sys0

   This determines the value of the maxuproc variable.
2. To reset the maximum number of processes allotted to a user, enter:

   chdev -a 'maxuproc=n_procs' -l sys0

   This sets the value of the maxuproc variable to the value of n_procs.

Increase Available System Paging Space

To increase the amount of available system paging space, use either the System Management Interface Tool (SMIT) facility or the lsps and chps commands:

1. To determine the current number of partitions within each paging device, enter:

   lsps -a

2. To increase the number of logical partitions (of 2 Mb each), enter:

   chps -s n_partitions page_device

   This increases the total number of partitions by n_partitions.

Increase SNA Services Default Limits

To run more than 200 HCON standalone sessions on your system, increase the default limits in the SNA Services server /dev/sna.

1. Enter smit sna from the command line.
2. Select the Configure SNA Profiles menu option.
3. Select the Nodes menu option.
4. Select the System Network Architecture  menu option.
5. Enter sna as the desired value of the PROFILE variable.
6. Set the value of the CONNECTIONS variable to the maximum allowable number of SNA standalone sessions to be run on your system.
7. Set the value of the SESSIONS and CONVERSATIONS variables to a number equaling twice the value of the CONNECTIONS variable.

   Note: It is not advisable to use a : (colon) when entering information into SMIT text-entry fields. SMIT interprets a : (colon) as a field delimiter.