linux-lecture6 LINUX SYSTEM ADMINISTRATION.ppt

Linux System Administration LINUX SYSTEM ADMINISTRATION SYS ADMIN TASKS Linux System Administration Setting the Run Level System Services User work Settings Scheduling Jobs Quota Management Backup and Restore Adding and Removing software/packages Setting a Printer Monitoring the system (general, logs) Monitoring any specific services running. Eg . DNS, DHCP, Web, NIS, NPT, Proxy etc. Init Runlevels Linux System Administration The following runlevels are defined in Linux: 0 - halt (Do NOT set initdefault to this) 1 - Single user mode 2 - Multiuser , work (The same as 3, if you do not working) 3 – Text Mode 4 - unused 5 – Graphical Mode 6 - reboot (Do NOT set initdefault to this) Init Runlevels Desktop Configuration The default runlevel for a system to boot to is configured in /etc/ inittab . id:5:initdefault: In GUI: Applications ? System Settings ? Server Settings ? Services Generally, Linux operates in runlevel 3 or 5. Linux Services Linux System Administration There are 113 deamons , Out of them, the following are most widely used: apmd : Power Management autofs : Automount services crond : mand Scheduler cups : Common Unix Printing System dhcpd : The DHCP server dovecot : IMAP ( Message Access Protocol) and POP3 (Post Office Protocol) server gpm : Mouse httpd : Apache Web server Linux Services Linux System Administration iptables : Kernel based Packet Filtering firewall kudzu: Finds new Hardware mysqld : MySQL server named : BIND server network : Networking nfs : Network File Share nfslock : NFS file locking ntpd : NTP (Network Time Protocol) server portmap : RPC (Remote Procedure Call) support postgresql : The Postgresql Database Engine Linux Services Linux System Administration sendmail : Sendmail Mail Server smb : work Services snmpd : work Management Protocol squid : Squid Proxy Server sshd : Open SSH and SFTP server syslog : System Logging d : Provides s