Three articles on the explanation of daemons
Here three articles cover the functions of the daemon and some explanations, you can provide some suggestions for friends who are ready to optimize system startup. The first article also has information on how to set hard drives, etc. Welcome everyone to read. From linuxsir.org
Customize their Linux application environment (a) Author: Cao Jianghua This article taken from: open systems world - SEOUL December 11, 2002 based on the open-source Linux provides users with a platform: according to their soft , Hardware environments, customize your Linux application environment. Therefore, the application environment can be customized according to each user different application range, and the performance of the Linux system can be improved to a new height. Custom System Services Linux requires a lot of system services to locally and network users, providing Linux system feature interfaces, directly for applications and users. However, services that open unnecessary or vulnerabilities will give the operating system security and performance. For system security, if any of the vulnerabilities in the operating system, the entire system may be attacked. Therefore, the best way to increase system security is to try to monitor the functionality of the system. As for how much services and functions, it is determined according to work needs and capabilities. The following is run as root: #ntsysv Figure 1 Remove the unwanted service and processes * to turn off the window as shown in Figure 1, where each system service can be turned on / off (as an example of RED FLAG 3.0). Remove the * in front of the service and processes that you do not need, then restart the system so that the unwanted service and process can no longer start. This method can be customized to customize system services at any time, not only safe and secure, but also improve the performance of the system, and two in one fell swoop. To protect Linux working properly, some system services are must be launched, such as Crond, Syslog, KeyTable, NFS, Kudzu. To efficiently customize the system service, the function of the various system services will be described below. Alsasound ALSA Sound Card Driver Support. The ALSA sound card driver is originally written for a sound card Gravis Ultrasound (GUS), which is compatible with OSS / Free and OSS / Linux. APMD is used to monitor the system's electricity status, and write related information to the log through Syslogd, or it can be used to shut down when the power is insufficient. Generally used for laptops, if the desktop is recommended to close. ATD runs batch tasks when the system load is relatively low. AutoFs automatically reprints the file system when needed, and automatically uninstall it when it is not required. The abbreviation generated by the Chargen port chargen character outputs a rotation sequence that prints characters for testing the character terminal device. CHARGEN UDP UDP format The abbreviation of the port chargen character is generated, and a rotation sequence that prints the character is used to test the character terminal device. Crond runs scheduled tasks based on the user request. It is more secure, configured, similar to Planning tasks in Windows. DHCPD provides access support for dynamic host control protocols (Dynamic Host Control Protocol). Echo port Echo simply responds to all data sent to test connections. Echo UDP UDP Format The port echo simply responds to all data sent to the test connection. GPM provides Linux programs in text mode, such as Mc (Midnight Commander) provides mice support. It also supports copy, paste operation, and pop-up menu under the console. inetd Internet Operating Server. Monitor the needs of network management services and start the corresponding service programs when necessary. Typically, inetd managed programs include Telnet, FTP, RSH, and Rlogin. Turning off inetd also closes these services managed by it. HTTP It is a famous WWW server that can be used to provide HTML files and CGI dynamic content services. The daemon of ISDN ISDN. The function of the program is the keyboard mapping table that reprints / etc / sysconfig / keyboards.
This table can be selected by the KBDConfig tool, which should cause the program to be active. Kudzu It is a hardware detection program, and the new hardware in Windows is similar. If the system supports the hardware, and if you have the driver, you can automatically load it. LinuxConf It is a valid system configuration tool for Linux, which allows remote operation. LinuxConf Web uses LinuxConf in web mode. The LPD system prints daemon is responsible for submitting LPRs and other programs to the print job. Medusa supports web browsers. MySQL a quick and efficient and reliable small SQL database engine. NTALK allows users to connect their own computers and other computers, and then transmit information forward or backward. Netfs is responsible for loading / unloading NFS, Samba, NCP (NetWare) file systems. Network activation / closes all network interfaces at startup. NFS is a popular, file sharing protocol based on TCP / IP network. This service provides NFS file sharing services, which are configured in the / etc / exports file. NSCD This service is responsible for password and group query and buffer query results. If the system has a relatively slow service (such as NIS and NIS ), you should start the service. PXE is used for remote diskless Linux system launched servers. PCMCIA is primarily used to support laptops. REXEC is a safe, decentralized remote execution system for cluster computers parallel and continuous operation. Random saves and recovers high quality random number generators. These random numbers are provided by some random behavior of the system. Routed This daemon supports automatic IP routing table maintenance of the RIP protocol. RIP is primarily used on a small network, and the big network needs a complicated protocol. RSYNC superimposed FTP Server allows loop inspection. RSH Remote host starts a shell and executes the user command. RWHOD allows remote users to get a list of all logged in users on the machine running the RWHo daemon, similar to Finger. Swat Samba's toolkit uses a 901 port. Sendmail mail server. SMB starts and closes SMBD and NMBD daemons to provide SMB network services. SNMPD Simple Network Management Protocol (SNMP) daemon. Syslog is a mechanism provided by operating systems, and daemons typically use this mechanism to write various information to each system log file. This service should usually start. The font server of the XFS X-WINDOW system. XINETD is an inetd inheritance service that monitors the needs of services to various management services, and starts the corresponding service programs when necessary. In these system services, the safety hazard is relatively large, RSH, RWHOD, Rexec, SNMP, Named, Sendmail. For system services that do need, you should try to use the latest version of the program and increase other security precautions. In addition, many Linux products launched the X-WINDOW Manager by default after the system initialization. If you only compile programs or edit a configuration file, starting the X-WINDOW Manager will consume a large number of system resources. The way to disable the X-WINDOW manager is: Edit the / etc / inittab file, find the content of the content for id: 5: initDefault, change it to ID: 3: INITDEFAULT, the system will provide command line login after restart. When you need to run the X-WINDOW manager, you can just enter STARTX. Optimization according to hardware 1.cpucpu is the core hardware of the Linux host, optimized at compile time according to CPU models. In the / etc / profile file, the configuration information of the system environment and the launcher is included in -O9 to compile the program, the running speed is also the fastest. Use the -FOMIT-FRAME-POINETR option while compile, the program is running the variable using the stack.
When using -mcpu = cpu-type and -march = CPU-TYPE, GCC is optimized for CPU models. If the CPU is Pentium Pro, PentiumII, PentiumIg III, AMD K6-2, K6-3, Althon, then in "/ etc / profile] Add: cflags = '- o9 -funroll-loops -ffast-math-malign-double -mcpu = PentiumPro-march = pentiumpro -fomit-frame-pointer -fno-exception "If the CPU is Pentium, Pentium MMX, AMD K5, IDT, Cyrix, then in" / etc / profile] Add: export cflags = -O3 -MARCH = Pentium-Matpu = Pentium -FFast-Math -funroll-loops -fomit-frame-pipe -force-mem -force-addr-malign-double -fno-exceptions2. Hard disk with UDMA / 33, 66, 100, 133 technology The maximum transmission rate is 33MB / s, 66Mb / s, 100Mb / s, 100Mb / s. In theory, it is an IDE hard disk (herein, the transmission rate is 16.6Mb / s) transmission rate of 3 to 6 times, but in the Linux default setting, DMA is disabled, so It must be opened. We can use the / sbin / hdparm program to open it. Some common options for HDPARM are as follows: / sbin / hdparm -c1 / dev / hda or HDB or HDC, etc. Enable 32-bit I / O mode transfer data on the PCI bus. / SBIN / HDPARM-D1 / DEV / HDA enables DMA mode transfer data. / sbin / hdparm -d1 -x66 / dev / hda enables Ultradma mode transfer data. Get the list of settings lists in the system is (as root) input: $ / sbin / hdparm / dev / hda then enter the command: $ / sbin / hdparm -kl / dev / hda keeps the hard disk remains after RESET The above settings. Once you have optimized everything to the best state, add a variety of commands to the /etc/rc.d/rc.local file, so that these commands are automatically run each time the system boots. 3. The memory usage can be observed using Free in Linux. If you find that Linux can only use some of them, you can add Append = "MEM = XXX" in /etc/lilo.conf, where xxx is physical memory capacity. This can tell Linux to use all memory. If the computational speed is required, it can be implemented by increasing memory, using RAMDISK technology. A a ramdisk is to assume memory to a hard drive and store files above it. Suppose there are several files to be used frequently. If they are added to memory, the program running speed is greatly improved because the memory is much higher than the hard disk. The partial memory improves overall performance, is not on replacing the new CPU. Computers like a web server require a lot of read and exchange specific files. Therefore, establishing RAMDISK on a web server will greatly improve network read speed.
$ mkdir / tmp / ramdisk0 $ mke2fs / dev / ram0 $ mount / dev / ram0 / tmp / ramdisk0 The above three commands will create a directory for RamDisk, format the RAMDISK (create part system), load the RAMDisk to the directory "/ TMP / RAMDISK0". Now, it can be used as a disk partition. Add the line below to your lilo.conf file: ramdisk_size = 20000 This way, Ramdisk's size will be 20MB after you type the lilo command and restart. If you have 512MB or more memory, 256MB is used as a temporary area / TMP, and when many programs are used to / TMP, such as web services, the system performance will greatly improve. After restarting, / TMP will be emptied. Note: Be sure to remember something useful in Ramdisk. The above introduces how to customize the Linux system application environment according to the work request, and finally emphasize that system backup is required. -------------------------------------------------- -----------------------------------------------
Ask: Linux start service interpretation Daquan (please know if you add a little, take the dragon to complete) Picked a lot of Linux systems, now I use RedHat7.2, but the system service is more and more, and it seems to be There is no special introduction to each service function. We don't know what the machine started, whether it reaches the optimized start mode.
So today, I have written all the Linux services I have ever seen. Please explain: Star, is the system default automatic service: freewnnamandaamd seems to manage Mixer devices)? AmIdxtape * anacron (command scheduling) * APMD (Advanced Power Management) ARPWATCH (Looking at ARP) * ATD (Function CRON Similar) * Autofs * BCM5820BGPDCWNNBOOTPARAMD (Startup Parameter Management?) Chargenchargen-UdpComsat * CRONDDAYTIME (DAEMON in summer time management) Daytime-UDP (UDP-User Data News Agreement, TCP) DBSKD-CDBDHCPD (Dynamic Host Service) Echo (Server Emotion Customer Data Service) Echo-UDP (UDP version Echo) Ekloginfinger (finger service) GATED (Gateway Service) * GPM (Mouse under the Console) GSSFTP (GSS FTP Server) HTTPD (Hypertext Protocol Service) IdentDimap (IMAP Protocol in Mail Service) IMAPS (IMAP Protocol in Mail Service) ?) InND (Internet News Service) * Ipchains (Firewall) IPOP2 (Spring 2) IPOP2 (Spring 2) IPOP3 (sending service of mail service) * iptables (firewall) Irda * iSCSI (using high speed line ?? SCSI disk array) * isdn (support for isdn devices) junkbusterkwnnkadminkdcrotatekeytable (keyboard configuration) klogin (remote login) kpropkrb5-telnet (What krb5 provide telnet services) krb524krb5kdckshell * Kudzuldap (directory service) * linuxconf (question: Why is LinuxConf to start as a service?) LinuxConf-web (open LinuxConF Web Configuration Port) * LPD (Support for printer) MCSERVMYSQLD (Support for Mysql Database) NAMED (Domain Name Server) * Netfs (Network File System) * NETWORK (Network File Support) NFS (Network File System) * NFSLOCK (Network File System Lock?) NSCDNTalk (Talk - Online Chat Service) NTPDoSPFTDSPFD * PCMICA (Support for PC Card POP3S (Isn't a POP3 server?) * Portmap (port mapping list, but not clear what is doing) PostgreSQL (providing support for Postgre SQL database) RADVD * Random (random number of high-precision data operations, why Usually to start automatically?) Rawdevices (like the support of the read and write device, such as a tape drive?) (Support remote configuration?) REXEC (remote execution?) RHNSDripdripngdrlogin (support remote login) ROUTED (Linux Routing Service) RSH (R shell?) RSTATDRSYNCRUSERSDRWALLDRWHOD * Sendmail (big name Ding Mail server) SMB (Is Samba? - Yes) SGI_FAMSNMPD (Simple Network Management Service) Squid (Proxy Server)
SWAT (901Web Configuration) * SYSTLOG (System Log Service) Talktelnet (Telnet Service) Time-UDP (UDP Removal System Time) TUX (like kernel-based high-speed static web) UPS (provided Control support for UPS?) VNCServer * Wine (executing Windows binary code directly under Linux!) Wu-ftpd (FTP server of Washington University. Very easy to use XFS (X Font Server) xinetd (new version of Internet Server) YPBINDYPASWDDYPSERVYHPXFRDZEBRA above It is some of the services I remember, you can explain some, all have explained, which also have your own questions, please all the best, if anyone knows the part or all, just explain it, more detailed, better ~ ~~~ Please let me help you, just like help us ...:) KEYTABLE (keyboard image, suitable for Korean, Japanese, Germany, etc.) Kzuzu ---- Start the system to detect the PC hardware has no change, For example, change the graphics card will prompt you to re-formulate the XF86 * GPM ----- seems to implement mouse's CP and Paste feature in the console mode. * Crond --- A UNIX-based regular command scheduler SWAT ------ Windows-based Samba Configuration Program XFS --- XWindows Font ServerBGPD (BGP Routing Protocol DAEMON) * GPM (Mouse Drive in Character Terminal) * ipchains (2.0 Kernel Firewall Process) * iptables (Firewall Process) Kshell (K Shell) ) NTALK (Network Talk Process) NTPD (Network Time Services Process) OSPFTD (OSPF Routing Protocol Process?) SPFD (SPF Routing Protocol Process?) RIPD (Roul Routing Protocol Process) SMB (Is Samba? )- is the Squid (Agent Service Process) Talk (should be a local Talk process) Zebra (a very famous routing service suite) ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- -------------------------------------------------- ------------------
Linux daemon introduction AMD: Automatically install NFS (Network File System) Shou Hou Process APMD: Advanced Power Management ARPWATCH: Record the log and build an Ethernet address and IP address as seen on the LAN interface and IP address AutoS: Automatic installation management process Automount Related to NFS, dependent on NIS Bootparamd: Boot Parameter Server, provides guidance required for the non-disk workstation on the LAN CROND: Linux plans DHCPD: Launch a DHCP (Dynamic IP Address Assignment) server Gated: Gateway Route Swing Process, using dynamic OSPF routing protocol httpd: web server inetd: Support for multiple network services, the core waiter for multiple network services, INND: USENET News Server LinuxConf: Allows the use of local web servers as user interfaces to configure machine LPD: print server MARS- NWE: MARS-NWE file and print server McServ: midnight command file server named: midnight command file server named: DNS server Netfs: Install NFS, Samba, and NetWare Network File System Network: Activate script programs configured network interface NFS: Open NFS service NSCD : NSCD (Name Switch Cache Daemon) server, a support service for NIS, high speed cache user password and forms member relationship Portmap: RPC Portmap Manager, similar to inetd, which manages RPC-based connection PostgreSQL: A SQL Database server ROUTED: Route Save Process, use dynamic RIP routing protocol RSTATD: A waiter RUSERD: Ruserd: Remote User Location Service, a RMC-based service, which is a RPC-based service. Record the user information of the LAN on a machine log Rwalld: Activate the RPC.Rwall service process, which is a RPC-based service that allows users to write messages to each other terminals on the LAN machine: Activate the RWHOD service process It supports LAN's RWHO and Ruptime service Sendmail: Mail Server Sendmail SMB: Samba File Sharing / Print Service SNMPD: Local Simple Network Management Process Squid: Activate Agent Server Squid Syslog: A Syslog and Klogd System Logging when you let the system boot The script of the process XFS: X WINDOW font servers, provides a word set for local and remote X servers xntpd: Network Time Server YPBIND: The NIS (Network Information System) Client Activates Ypbind Service Process YpSwdd: NIS Password Server Ypserv: NIS Primary Server GPM: The Identd: Auth Service of the Mouse is available in providing user information. What is the function of the boot service? What can be turned off? Linux To launch a lot of system services while starting, providing local and network users with Linux system function interface, direct application and user. However, services that open unnecessary or vulnerabilities will give the operating system security and performance. Below we take the boot service of BluePoint Linux 2.0 as an example, the list describes the functions of the services.
Alsasound ALSA Sound Card Driver Support. The ALSA sound card driver was originally written for a sound card Gravis Ultrasound (GUS), which was clearly excellent, so the author started to write drivers for the general sound card. ALSA and OSS / Free and OSS / Linux are compatible, but have their own interface, even better than OSS. AMD runs the Automount Elf program, which automatically installs some local devices and NFS file systems when necessary. The APMD APMD is used to monitor the system's electricity status and write related information to the log through Syslogd. It can also be used to shut down when the power is insufficient. ARPWATCH This program is mainly used to maintain the correspondence between the Ethernet physical address and the IP address. Atalk AppleTalk wizard. Be careful not to run the program in the background, the data structure of the program must be initialized for a certain period of time before running other processes. ATD runs the task that the user scheduling with the AT command. Batch tasks are also run when the system load is relatively low. Autofs automatically reprints the file system when you need it, and automatically uninstall when you don't need it. Bootparamd This service allows old Sun workstations to start from Linux network, which is rarely used with RARP, basically replaced by bootp and dhcp. Crond cron is a traditional program under UNIX that periodically runs user scheduling tasks. Compared to traditional UNIX versions, the Vixie version adds a few attributes, and is safer and simpler. DHCPD This wizard provides access support for dynamic host control protocols (Dynamic Host Control Protocol). Gated Gated provides network routing function support through a database. It supports various route protocols, including RIP versions 1 and 2, DCN Hello protocol, OSPF version 2, and EGP versions 2 to 4. GPM GPM provides a mouse support for Linux programs for text mode such as MC (Midnight Commander). It also supports copy, paste operation, and pop-up menu under the console. HTTPD HTTP is a famous WWW server that can be used to provide HTML files and CGI dynamic content services. inetd Internet Operating Server. Monitoring the needs of the network to various services of its management, and start the corresponding service programs when necessary. Typically, inetd managed programs include Telnet, FTP, RSH, and Rlogin. Turning off inetd also closes these services managed by it. InND Inn is the most popular user group news server. It allows you to build a local news server. Configure a certain difficulty, you can read the / usr / doc / inn * document first. The keytable functionality is to reprint the keyboard mapping table that you speak in / etc / sysconfig / keyboards, which can be selected by the KbdConfig tool. You should make the program in an activation state. LDAP LDAP represents LightWeight Directory Access Protocol, implements industry standards for directory access protocols. LinuxConf LinuxConf is a valid system configuration tool under Linux that allows remote operation. LPD LPD is the system print daemon, which is responsible for submitting LPRs and other programs to the print job. The MCSERV MIDNIGHT COMMANDER service process allows users on the remote machine to operate the native files via the Midnight Commander File Manager. The service process uses PAM to verify the user, and "user name / password" needs to be given. MySQL a quick and efficient and reliable light SQL database engine. Named Domain Name Server, resolve the Internet hostname into points of the IP address. Netfs is responsible for loading / unloading NFS, Samba, NCP (NetWare) file systems. Network activation / closes all network interfaces at startup. NFS NFS is a popular file sharing protocol based on TCP / IP network.
This service provides NFS file sharing services, which are configured in the / etc / exports file. NSCD This service is responsible for password and group query and buffer query results. If your system has a relatively slow service (such as NIS and NIS ), you should start the service. PCMCIA PCMCIA is mainly used to support laptops. Portmap portmap is used to support RPC connections, RPC is used for NFS and NIS and other services. PostgreSQL PostgreSQL Relational Database Engine. Proftpd ProftPD is a flexible FTP daemon under UNIX. RADVD routing broadcast program. Random saves and recovers the system's high quality random number generator, which is provided by the system. Routed This daemon supports automatic IP routing table maintenance of the RIP protocol. RIP is primarily used on a small network, and the big network needs a complicated protocol. The RSTATD RSTAT protocol allows users on the network to get performance parameters of each machine on the same network. RUSERSD This service allows network users to locate other users on the same network. The RWALLD RWALL protocol allows remote users to send messages to terminals that are active in the same system, similar to Wall local behavior. RWHOD allows remote users to get a list of all logged in users on the machine running the RWHo wizard, similar to finger. Sendmail's famous Mail server. SMB starts and closes the SMB and NMBD wizards to provide SMB network services. Snmpd Simple Network Management Protocol (SNMP) Guardian Wizard. Syslog syslog is a mechanism provided by operating systems, and daemons typically use this mechanism to write various information to each system log file. This service should usually start. XFS X font servers. YPBIND NIS / YP client daemon. If you need to use the NIS / YP machine, launch this service, otherwise, close this service. YPASSWD allows NIS users to modify passwords. Run on the server in the NIS domain. The client program is also called yppasswd. A implementation of the YPSERV standard NIS / YP network protocol. Allow host names, usernames, and other information to be distributed across the network. Run on the NIS server, the client does not need. - Author: redcat8850 January 28, 2005, Friday 00:12
