Swap Space Bottleneck During SAP Operation

Symptom

Various error messages that indicate a storage bottleneck (more correctly: a swap space shortfall) such as: System Panic; cmemreserve: reservation overrun; ENOMEM, Not enough core; ENOSPC, No space left on device; SIGDANGER (only under AIX). In the SAP system the SAP system log message " no memory of class perm" is output.

This problem can occur with both SAP processes and external processes. The relevant process cannot allocate any more heap memory. This can lead to the database operation being ended or SAP work processes being stopped.

In the SAP system, error messages appear in the developer trace files dev_disp, dev_w<n>, in the system log and in dumps. The following messages may appear: TSV_TNEW_;._NO_ROLL_MEMORY; NO_MEM; NO_MEMORY; RESIZE_EM_ALLOC_ERROR, Storage class PERM.

This problem mostly occurs if background jobs are active with large amounts of data.

Possible Causes

• There is no more swap space available ( Swap Space Requirements).

• The highest value for one of the SAP profile parameters that limit the swap space usage has been exceeded. In this case, the following parameters are relevant: abap/heap_area_dia, abap/heap_area_nondia and abap/heap_area_total.

Corrective Action

Increase the swap space as described in Swap Space Requirements.