centos下简单的优化内存的方法

sxyzy

　　使用sync命令将所有未写的系统缓存区write to disk，包含已修改的i node、已延迟的块I\O和读写映射
sync
cat /proc/sys/vm/drop_caches
echo 3 > /proc/sys/vm/drop_caches[可以将3修改为别的 1清空页缓存 2清空inode和目录树缓存  3清空所有的缓存]
清理tmp命令:
find /tmp/ -name "p*" | xargs rm -rf
yum -y install crontabs
修改etc/crontab文件为以下
SHELL=/bin/bash
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MAILTO=root
HOME=/
# For details see man 4 crontabs
# Example of job definition:
# .---------------- minute (0 - 59)
# |  .------------- hour (0 - 23)
# |  |  .---------- day of month (1 - 31)
# |  |  |  .------- month (1 - 12) OR jan,feb,mar,apr ...
# |  |  |  |  .---- day of week (0 - 6) (Sunday=0 or 7) OR sun,mon,tue,wed,thu,fri,sat
# |  |  |  |  |
# *  *  *  *  * user-name command to be executed
10 * * * * root echo 3 > /proc/sys/vm/drop_caches
10 1 * * * root find /tmp/ -name "p*" | xargs rm -rf

设置每天清理一次tmp文件夹
修改/etc/cron.daily/tmpwatch[30d修改为1d]
#! /bin/sh
flags=-umc
/usr/sbin/tmpwatch "$flags" -x /tmp/.X11-unix -x /tmp/.XIM-unix \
-x /tmp/.font-unix -x /tmp/.ICE-unix -x /tmp/.Test-unix \
-X '/tmp/hsperfdata_*' 10d /tmp
/usr/sbin/tmpwatch "$flags" 10d /var/tmp
for d in /var/{cache/man,catman}/{cat?,X11R6/cat?,local/cat?}; do
    if [ -d "$d" ]; then
/usr/sbin/tmpwatch "$flags" -f 10d "$d"
    fi
done


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