49、系统安全与性能调优全攻略

系统安全与性能调优全攻略

1. 系统服务状态与安全风险

系统中存在众多服务，其状态各异，部分服务存在潜在安全漏洞。以下是一些常见服务的状态列表：
| 服务名称 | 运行级别 0 | 运行级别 1 | 运行级别 2 | 运行级别 3 | 运行级别 4 | 运行级别 5 | 运行级别 6 |
| — | — | — | — | — | — | — | — |
| ypserv | off | off | off | off | off | off | off |
| autofs | off | off | off | off | off | off | off |
| dhcpd | off | off | off | off | off | off | off |
| mysqld | off | off | off | on | on | on | off |
| nscd | off | off | off | off | off | off | off |
| ntpd | off | off | off | off | off | off | off |
| squid | off | off | off | off | off | off | off |
| vmware | off | off | off | on | off | off | off |
| apcupsd | off | off | off | on | off | off | off |
| mysqld−skip | off | off | off | off | off | off | off |
| p