1, BIOS self-test
2, run the system kernel and detect hardware
3, the first process of running the system init
4, init reading system boot configuration file / etc / initTab in initialization
l /etc/rc.d/rc.sysinit ------ System Initialization script
l /etc/rc.d/rcx.d/[KS]*----- Configure the service according to the run level
l /etc/rc.d/rc.local ------- Perform local special configuration
l Others -------- special services at different runs
/ * Guarding process * /
//concept
Usually the service providing service on the Linux system is performed by the daemon (daemon) running in the background. These programs are called "service" in the Windows system.
The job of the daemon is a port that opens and waits for access.
//Operation mode
1, the independent process is running
l Managed by the init script
l Script is stored in /etc/init.d/ directory
l All system services are run independently.
2, running by the network daemon service
l Start by xinetd
l There is /etc/xinetd.d/ directory by the profile of the daemon manager management.
l Default xinetd configuration file is /etc/xinetd.conf
l xinetd itself is a daemon of independent operation
/ / View process tree
# pstree
/etc/xinetd.conf file
#
# Simple Configuration File for Xinetd
#
# Some deflults, and include /etc/xinetd.d/
Defaults // Default value for all services
{
/ / Run the maximum number of processes at the same time
INSTANCES = 60
/ / Specify the service registration using Syslogd
LOG_TYPE = SYSLOG Authpriv
/ / Specify the PID of the client mechanism IP and process when you specify
Log_on_success = host pid
LOG_ON_FAILURE = Host
CPS = 25 30
}
INCLUDIR / Etc/xinetd.d
/etc/xinetd.d/telnet
# Default: ON
# Description: The Telnet Server Serves Telnet sessions; IT Uses /
# Unencrypted Username / Password Pairs for Authentication.
Service telnet
{
/ / Indicates that this service is not allowed
Disable = yes
/ / TCP / IP Socket can be reused when interrupting or restarting xinetd
Flags = Reuse
// use TCP Socket Type
Socket_type = stream
/ / For NO, indicating that multi-threaded function
Wait = NO
/ / Indicates the UID of the setting process
User = root
// Operation path of the service
Server = /usr/sbin/in.telnetd
// Add the failure of the UID to the system registration form
LOG_ON_FAILURE = UserID
}
// Startup Process Tools
# NTSYSV
# chkconfig -list [server-name]
# chkconfig -Add Server-Name
# chkconfig -del server-name # chkconfig [-LEVEL Levels] Server-Name
# chkconfig [-LEVELS] Server-name
