Solution : https://service.sap.com/sap/support/notes/1557506 (SAP Service marketplace login required)
Summary :
SAP systems may face high swapping on Linux, causing slow application response times during activities like filesystem backups. This often happens despite adequate sizing due to the Linux kernel using spare memory for its page cache, which holds disk data to speed up future access but can push application data to swap under memory pressure. Adjusting the `vm.swappiness` parameter can mitigate this by prioritizing application memory over cache during high disk usage periods. Additionally, newer kernel features in SLES for managing page cache sizes (`vm.pageb0cach_ag@lin_limit_mb` and `vm.pagecache_limit_ignore_dirty`) offer better control by bounding the cache size, thereby preserving more memory for application use. These settings should be tweaked cautiously as they can affect system performance.
Key words :
customer component bc-op-lnx-suse suse linux priority recommendations / additional info category performance validity, technical details /proc/sys/vm/pagecache_limit_mbthis tunable sets, /usr/src/linux/documentation/vm/pagecache-limitfrom, /proc/sys/vm/pagecache_limit_ignore_dirtythis tunable influences, suse linux enterprise server 11 sp1, sap pilot customer systems, limiting local write back caching, software component version references, /proc/sys/vm/pagecache_limit_ignore_dirty, /proc/sys/vm/dirty_ratio
Related Notes :
| 171356 | SAP software on Linux: General information |