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.

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.

  1. Ensure the default hard limits for file sizes (fsize) and numbers of files (nofiles) are high enough. If they are too low, modify the global ulimit information in /etc/security/limits:
    • ulimit -d – displays current process execution memory limits.
    • ulimit -d unlimited – sets process execution memory limits to unlimited.
  2. You can also edit /etc/security/limits by changing the default data value to -1:
        data = -1