主机升级zabbix-agent升级之后，部分item不可用， zagent.disk.iostat[xvda1,write_bytes]

zabbix报错提示：
Preprocessing failed for: /usr/lib/python2.7/dist-packages/pkg_resources.py:1031: UserWarning: /tmp/zagent/.python_eggs is ...
1. Failed: cannot calculate delta (speed per second) for value of type "string": cannot convert value to numeric type

定位过程：
登上主机手动运行：/opt/zagent/bin/Zagent.py -k zagent.disk.io_count[xvda1,read_bytes]
报错截图如下：（大概意思是/tmp/zagent/.python_eggs可被组/其他用户写入，与get_resource_filename一起使用时容易受到攻击）
/usr/lib/python2.7/dist-packages/pkg_resources.py:1031: UserWarning: /tmp/zagent/.python_eggs is writable by group/others and vulnerable to attack when used with get_resource_filename. Consider a more secure location (set with .set_extraction_path or the PYTHON_EGG_CACHE environment variable).
warnings.warn(msg, UserWarning)
1910804480
看报错提示，是权限问题。当前权限：
drwxrwxr-x 4 zabbix zabbix 4096 May 2 2018 .python_eggs/
修改权限为：chmod 755 ./.python_eggs
drwxr-xr-x 4 zabbix zabbix 4096 May 2 2018 .python_eggs/
警告提示消失。item恢复。