Installation guide

SAP ASE and client applications use network software even when they are installed on a machine that is not

connected to a network.

If you are having connection problems, or to verify your network configuration, ping the host.

13. Adjust the shared memory for your operating system.

6.5.1 Adjusting the Operating System Shared Memory

Parameters

Adjust shared memory segments if SAP ASE cannot obtain large memory as a single segment, or if Backup Server

stripes fail due to insufficient segments.

Context

Depending on the number and types of devices used for backup (dump) and recovery (load), you may need to

adjust the shared memory segment parameter in the operating system configuration file to accommodate

concurrent Backup Server processes. There are six default shared memory segments available for process

attachments.

If any reconfiguration through sp_configure requires additional memory, SAP ASE allocates shared memory

segments after start-up. To account for these additional segments, allocate the maximum memory that is

available to SAP ASE by using the allocate max shared memory configuration parameter. See the System

Administration Guide.

Procedure

1. The operating system shared memory default, for most Linux releases, is 32MB. The minimum required by

SAP ASE is 64MB for a default server that uses 2K pages. A higher value is required if you plan to increase the

SAP ASE server’s total memory. Set the stack size to unlimited to avoid shared memory attachment

problems. Set this using ulimit -s unlimited on the Bourne shell, or limit stacksize unlimited on

the C shell.

2. To check and adjust the operating system shared memory parameter, use the sysctl(8) method:

To check the current shared memory size, enter:

# /sbin/sysctl kernel.shmmax

To adjust the shared memory size at runtime, enter the following, where <nnn> is 1073741824 for 1GB of

shared memory:

# /sbin/sysctl -w kernel.shmmax=nnn

Installation Guide for Linux

Planning Your SAP ASE Installation