--安裝背景
上次碰到問題，cursor：mutex S導致的load過高， 有說可以升級到11.2.0.4就能避免這種問題，所以準備重新搭建新版本11.2.0.4。
安裝環境是：azure云 linux centos6.5。
1，修改內核
1.1 修改sysctl.conf文件
[root@orcltest Downloads]# vim/etc/sysctl.conf# add by tim.mankernel.shmmax = 277495689510912kernel.shmmni = 4096kernel.sem = 250 32000 100 128net.core.rmem_default = 262144net.core.rmem_max = 4194304net.core.wmem_default = 262144net.core.wmem_max = 1048586fs.file-max = 6815744 # Controls the maximum number of shared memory segments, in pages kernel.shmall = 4294967296net.ipv4.tcp_max_tw_buckets = 6000net.ipv4.ip_local_port_range = 9000 65500net.ipv4.tcp_tw_recycle = 0net.ipv4.tcp_tw_reuse = 1net.core.somaxconn = 262144net.core.netdev_max_backlog = 262144net.ipv4.tcp_max_orphans = 262144net.ipv4.tcp_max_syn_backlog = 262144net.ipv4.tcp_synack_retries = 2net.ipv4.tcp_syn_retries = 1net.ipv4.tcp_fin_timeout = 1net.ipv4.tcp_keepalive_time = 30net.ipv4.tcp_keepalive_probes = 6net.ipv4.tcp_keepalive_intvl = 5net.ipv4.tcp_timestamps = 0fs.aio-max-nr = 1048576
1.2 使參數生效