解决ubuntu18下桌面经常卡死的问题

# vim freemem.sh
 
#!/bin/bash
used=`free -m | awk ‘NR==2‘ | awk ‘{print $3}‘`
free=`free -m | awk ‘NR==2‘ | awk ‘{print $4}‘`

filename=/var/log/mem.log
filesize=`ls -l $filename | awk ‘{ print $5 }‘`
maxsize=$((1024*2))
if [ $filesize -gt $maxsize ]
then 
	sudo rm $filename
else
	echo ""
fi


echo "===========================" >> /var/log/mem.log
date >> /var/log/mem.log
echo "Memory usage | [Use：${used}MB][Free：${free}MB]" >> /var/log/mem.log
 
if [ $free -le 100 ] ; then
                sync && echo 1 > /proc/sys/vm/drop_cach
                sync && echo 2 > /proc/sys/vm/drop_caches
                sync && echo 3 > /proc/sys/vm/drop_caches
                echo "OK" >> /var/log/mem.log
else
                echo "Not required" >> /var/log/mem.log
fi

sudo crontab -e

结尾添加：
*/1 * * * *  sudo sh /home/dxs/software/freemem.sh
## 意思是：设置每1min执行一次，会自动写入之前脚本里指定的log 

重启服务：
sudo service cron restart

=============================
修改rsyslog

sudo vim /etc/rsyslog.d/50-default.conf

cron.*              /var/log/cron.log    #将cron前面的注释符去掉 

重启rsyslog

sudo  service rsyslog  restart
sudo service cron restart


查看crontab日志

 tail -f /var/log/cron.log