Solution : https://service.sap.com/sap/support/notes/1672954 (SAP Service marketplace login required)
Summary :
This SAP Note provides detailed insights into the implementation and advantages of using hugepages with an Oracle database running on Linux systems. It highlights the significant memory savings and reduced CPU usage achievable through minimized page table entries (PTEs) due to larger page sizes. The note outlines specific steps for configuring hugepages both at the operating system level, involving kernel parameter adjustments and system configuration files, and at the Oracle database level via the use_large_pages parameter with options like 'true', 'false', 'only', and 'auto'. The effective use of hugepages helps lock the SGA into RAM, preventing it from being paged out during memory shortages, thus optimizing database performance. However, it cannot be used simultaneously with Automatic Memory Management (AMM).
Key words :
<oracle binary os owner> soft memlock unlimited <oracle binary os owner> hard memlock unlimitedif, grep oralas oralas soft memlock unlimited oralas hard memlock unlimited steps, 5972e+10 bytes database buffers 5368709120 bytes redo buffers 36102144 bytes sql> # ipcs -, 1379e+10 bytes fixed size 2235904 bytes variable size 1, huge pages information huge pages memory pool detected, grep <oracle binary os owner>, grep oralas 0x38671d2c 3997702 oralas 660 21476933632 30calculate, communication channel use_large_pages=auto option auto, # grep hugepages /proc/meminfoadditional change required, larger page size lowering cpu usage
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