Article Directory
1. Service management summary mind map
Start to summarize:
Regarding service startup:
(1) The startup method of a service in Linux is to find its executable file with an absolute path, and then follow the startup parameters. The source code package uses the absolute path to find the startup script and adds startup parameters. Different source code packages have different starting paths. Each source package will tell itself how to start it in the installation instructions. Encounter an unfamiliar source package to check its installation instructions.
(2) If you change to Linux or liunx, the service cannot be used. If Linux is a minimal installation, even if you are using the Redhat series, if the service is not installed, you cannot use it for management.
Regarding service self-starting:
(1) The environment variable configuration file is read after entering the user name and password. And /etc/rc.d/rc.local is read before entering the user name and password, so it is not recommended to modify the environment variables in this file (because the variables will be overwritten). The service is usually started in this file. Just write in the service's self-start command. ntsysv graphical management. The self-start of the service can be modified in batches, Redhat proprietary. To make a service start automatically, it is recommended to start it by modifying the configuration file.
(2) The service based on xinetd cannot use this method of modifying the configuration file to start automatically, because there is no auto-start command. Must rely on xinetd service itself. The xinetd-based service startup and self-starting are common. This kind of service is rare.
(3) The service installed by the source code package can be changed and recognized by the service through configuration (soft link). Then add two lines of comments to the startup file to be recognized by chkconfig and ntsysv. Suggestion: Don't do it like this, it's easy to enigma, if you don't faint, a teammate will faint. Master these management methods proficiently and use them according to the category.
2. Linux common services
| service name | Function introduction | Suggest |
|---|---|---|
| acpid | Power management interface. If it is recommended for notebook users to enable it, you can monitor related power events at the kernel layer | Turn on |
| anacron | System timing task program. A subsystem of cron, if the timing task misses the execution time, it can continue to wake up and execute through anacron | shut down |
| alsasound | Alsa sound card driver. If using alsa sound card, turn on | shut down |
| apmd | Power management module. If acpid is supported, apmd is not needed and can be turned off | shut down |
| etc | Specify the system to execute a task at a specific time, and it can only be executed once. Turn it on if necessary, but we generally use crond for cyclic timing tasks | shut down |
| auditd | Audit subsystem. If this service is enabled, SELinux audit information will be written to the /var/log/audit/audit.log file, if not enabled, the audit information will be recorded in syslog | Turn on |
| autofs | Allows the server to automatically mount the shared data of other servers in the network, generally used to automatically mount the NFS service. If there is no NFS service, it is recommended to close | shut down |
| avahi-daenon | Avahi is an implementation of the zeroconf protocol. It can find devices and services based on the zeroconf protocol in the local area network without DNS service, unless there is a compatible device or use the zeroconf protocol, otherwise close | shut down |
| bluetooth | Bluetooth device support, generally will not enable Bluetooth devices on the server, turn it off | shut down |
| leaders | Only useful for users who use ISND equipment. | shut down |
| batch-dgram | Chargen server using UDP protocol, the main function is to provide functions similar to remote typing | shut down |
| batch stream | Same as above | shut down |
| cpuspeed | You can use Thunder to adjust the CPU frequency. When idle, the CPU frequency can be automatically reduced to save power | Turn on |
| crond | System timing tasks, general Linux servers need timing task help | Turn on |
| cvs | A version control system | shut down |
| daytime-dgram | daytime uses the daytime daemon of the TCP protocol, which implements the function of obtaining the date and time from the remote server for the client | shut down |
| daytime-stream | Same as above | shut down |
| dovecot | The daemon of the mail service pop3/IMAP service. Mainly used to receive mail, if the mail service is activated, turn it on, otherwise turn it off | shut down |
| echo-dgran | The server echoes the process of customer service | shut down |
| echo-stream | Same as above | shut down |
| firstboot | 系统安装完成之后，有个欢迎界面，需要对系统进程初始设定。就是这个进程的作用。既然不是第一次启动了，关闭吧 | 关闭 |
| gpm | 在字符终端（tty1-tty6）中可以使用鼠标赋值和粘贴。就是这个服务的功能 | 开启 |
| haldaenon | 检测盒支持USB设备。如果是服务器可以关闭，个人机建议开启 | 关闭 |
| hidd | 蓝牙鼠标、键盘等蓝牙设备检测。必须启动bluetooth服务 | 关闭 |
| hplip | HP打印机支持，如果没有打印机，就关闭 | 关闭 |
| httpd | apache服务的守护进程。如果需要启动apche,就开启 | 开启 |
| ip6tables | IPv6的防火墙，目前IPv6协议并没有使用，可以关闭 | 关闭 |
| iptables | 防火墙功能，Linux中防火墙是内核支持功能，这时服务器的主要防护手段，必须开启 | 开启 |
| irda | irda提供红外线设备（笔记本，PDA‘s，手机，计算器等等）间的通讯支持 | 关闭 |
| irgbalance | 支持多核处理器，让CPU可以自动分配系统中断（IRQ），提高系统性能。目前服务器多是多核CPU，请开启 | 开启 |
| isdn | 使用ISDN设备连接网络。目前主流的联网方式是光纤接入和ADSL，ISDN已经非常少见，请关闭 | 关闭 |
| kudzu | 该服务可以在开机时进行硬件检测，并会调用相关的设置软件。建议关闭，仅在需要时开启 | 关闭 |
| lvm2-monitor | 该服务可以让系统支持LVM逻辑卷组，如果分区采用的是LVM方式，那么应该开启。建议开启 | 开启 |
| mcstrans | SELinux的支持服务。建议启动 | 开启 |
| mdmonitor | 该服务用来检测softvare RAID 或 LVM的信息。不是必须服务，建议关闭 | 关闭 |
| mdmpd | 该服务用来检测Multi-Path设备。不是必须服务 | 关闭 |
| messagebus | 这时Linux的IPC（Interprocess Communication进程间通信）服务，用来在各个软件中交换信息。个人建议关闭 | 关闭 |
| microcode ctl | Intel系列的CPU可以通过这个服务支持额外的微指令集 | 关闭 |
| mysqld | mysql数据库服务器。如果需要就开启，否则关闭 | 开启 |
| named | DNS服务的守护进程，用来进行域名解析。如果是DNS服务器则开启，否则关闭 | 关闭 |
| netfs | 该服务用于在系统启动时自动挂载网络中的共享文件空间，比如：NFS，Samba等等，需要就开启，否则关闭 | 关闭 |
| network | 提供网络设置功能。通过这个服务来管理网络，所以开启 | 开启 |
| nfs | NFS（Network File System）服务，Linux与Linux之间的文件共享服务。需要就开启，否则关闭 | 关闭 |
| nfslock | 在Linux中如果使用了NFS服务，为了避免同一个文件被不同的用户同时编辑，所以有这个锁服务。有NFS时开启，否则关闭 | 关闭 |
| ntpd | 该服务可以通过互联网自动更新系统时间，使系统时间永远都转却，需要则开启，但不是必须服务 | 关闭 |
| pcscd | 智能卡检测服务，可以关闭 | 关闭 |
| portmap | 用在远程过程调用（RPC）的服务，如果没有任何RPC服务时，可以关闭。主要是NFS和NIS服务需要 | 关闭 |
| psacct | 该守护进程支持几个监控活动的工具 | 关闭 |
| rdisc | 客户端ICMP路由协议 | 关闭 |
| readahead_early | 在系统开机的时候，先将某些进程加载，如内存整理，可以加块一点启动速度 | 关闭 |
| readhead_later | 同上 | 关闭 |
| restorecond | 用于给SELinux检测和重新加载正确的文件上下文。如果开启SELinux则需要开启。 | 关闭 |
| rpcgssd | 与NFS有关的客户端功能。如果没有NFS就关闭 | 关闭 |
| rpcidmapd | 同上 | 关闭 |
| rsync | 远程数据备份守护进程 | 关闭 |
| sendmail | sendmail邮件服务的守护进程。如果有邮件服务就开启，否则关闭 | 关闭 |
| setroubleshoot | 该服务用于将SELinux相关信息记录在日志//var/log/messages中。建议开启 | 开启 |
| snartd | 该服务用于自动检测硬盘状态。建议开启 | 开启 |
| snb | 网络服务sanba的守护进程。可以让Linux和Windows之间共享数据。如果需要则开启。 | 关闭 |
| squid | 代理服务的守护进程。如果需要则开启，否则关闭 | 关闭 |
| sshd | ssh加密远程登陆管理的服务。服务器的远程管理必须使用此服务，不要关闭 | 开启 |
| syslog | 日志的守护进程 | 开启 |
| vsftpd | vsftp服务的守护进程。如果需要FTP服务则开启，否则关闭 | 关闭 |
| xfs | This is the font daemon of xwindows. Provide font service for the graphical interface, if you don’t start the graphical interface, you don’t need to open it | shut down |
| xinetd | Super daemon. If there are services that rely on xinetd, they must be turned on. | Turn on |
| ypbind | Activate the ypbind service process for NIS (Network Information System) clients | shut down |
| yum-updatesd | Yum online upgrade service | shut down |
hint:
(1) In Linux or server, whether it is Linux or Windows, when doing optimization, the most important task is to stop unnecessary services.Benefits: The server system occupies fewer resources, and the fewer external services provided, the less likely it is to be attacked.
(2) Startup suggestion: It must be turned on, generally speaking, it is necessary. The system timing task, as long as it is Linux, generally must be turned on. Generally, MySQL with source code package is installed. If SELinux is turned on, its log must also be turned on. ssh must be opened, and Linux cannot be remotely managed if it is not opened.