to pagecache and swapcache reclaim. Decreasing vfs_cache_pressure causes the kernel to prefer to retain dentry and inode caches. Increasing vfs_cache_pressure beyond 100 causes the kernel to prefer to reclaim dentries and inodes.
vm.swappiness:default 60,Apparently /proc/sys/vm/swappiness on Red Hat Linux allows the admin to tune how aggressively the kernel swaps out processes'memory. Decreasing the swappiness setting may result in improved Directory performance as the kernel holds more of the server process in memory longer before swapping it out.
设置以下值，以减少OOM(Out Of Memory)的可能性:
# Oracle-Validated setting for vm.min_free_kbytes is 51200 to avoid OOM killer
vm.min_free_kbytes = 51200
vm.swappiness = 40
vm.vfs_cache_pressure = 200