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Grundlagen für Redhat / CentOS7
Basis Know-How Redhat Systems
System Aktualisieren / Warten
Grundlegende Systemwartung, durch Installation, von aktuellen Paketen und Upgraden des Kernels.
Upgrade System and Packages:
# yum -y update
Autocomplete in Shell aktivieren
Will man die automatische Syntax Erweiterung durch drücken von “Tab, Tab” einrichten, so müssen lediglich folgende zwei Packete auf dem System installiert werden; und ein relogin nach der erfolgreichen Installation durchgeführt werden.
# yum install bash-completion.noarch # yum install bash-completion-extras.noarch
motd - Message of the day
Eigene motd (Login-Nachricht), nach dem Aufbau einer neuen SSH-Verbindung anzeigen lassen:
Add description and serial number to motd:
# echo ' ############################################################################## # # # This is the admin-server of Michael Reber. # # # # ATTENTION: # # # # Unauthorized access to this system is prohibited ! # # # # This system is actively monitored and all connections may be logged. # # By accessing this system, you consent to this monitoring. # # # ############################################################################## ' > /etc/motd
Systemverwaltung
Wichtige Tools, zum konfigurieren, abändern der System Einstellungen.
Wechseln der Zeitzone
Die aktuelle System-Zeitzone(Timezone) kann man sehr einfach anschauen:# timedatectl
Wenn man nun auf eine neue Timezone zu wechseln möchte, macht es sinn, sich zuerst die verfügbaren Zeitzonen anzuzeigen lassen:# timedatectl list-timezones
- Um nun die aktuelle Timezone (Zeitzone) zu wechseln, verwendet man set-timezone zusammen mit der gewünschten TIMEZONE. Beispiel für die Schweiz:
# timedatectl set-timezone Europe/Zurich
System Information
Möglichkeiten, um das eigene System ein bisschen zu analisieren; Informationen abzurufen.
Show Uptime
# uptime
11:09:46 up 81 days, 17:13, 1 user, load average: 0.04, 0.10, 0.08
Show Kernel Version and Architecture
Display the current Kernel Version:# uname -a
Linux vstif2.pnet.ch 3.10.0-514.21.1.el7.x86_64 #1 SMP Sat Apr 22 02:41:35 EDT 2017 x86_64 x86_64 x86_64 GNU/Linux
Show System Server Release Version:# cat /etc/redhat-release
Red Hat Enterprise Linux Server release 7.4 (Maipo)
Show Disk Partitions details
# df -h
Filesystem Size Used Avail Use% Mounted on /dev/mapper/vgsys-root 8.0G 2.1G 6.0G 26% / devtmpfs 910M 0 910M 0% /dev tmpfs 920M 0 920M 0% /dev/shm tmpfs 920M 97M 824M 11% /run tmpfs 920M 0 920M 0% /sys/fs/cgroup /dev/mapper/vgsys-var 8.0G 2.1G 6.0G 26% /var /dev/mapper/vgsys-opt 9.5G 184M 9.3G 2% /opt /dev/mapper/vgsys-tmp 4.0G 33M 4.0G 1% /tmp /dev/mapper/vgsys-home 8.0G 7.1G 922M 89% /home /dev/vda1 509M 195M 315M 39% /boot tmpfs 184M 0 184M 0% /run/user/37198
Show all Disks and relation
Zeigt alle Disks an, auch welche die unpartitioniert sind, und nicht gemountet sind!
# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 0 80G 0 disk ├─sda1 8:1 0 512M 0 part /boot └─sda2 8:2 0 79.5G 0 part ├─vgsys-root 253:0 0 8G 0 lvm / ├─vgsys-swap 253:1 0 2G 0 lvm [SWAP] ├─vgsys-opt 253:2 0 49.5G 0 lvm /opt ├─vgsys-tmp 253:3 0 4G 0 lvm /tmp ├─vgsys-home 253:4 0 8G 0 lvm /home └─vgsys-var 253:5 0 8G 0 lvm /var sdb 8:16 0 80G 0 disk └─vg_data01-lv_data01 253:6 0 80G 0 lvm /data01 sr0 11:0 1 1024M 0 rom
Show Open Ports
# netstat -napl
Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 0.0.0.0:111 0.0.0.0:* LISTEN 1/systemd tcp 0 0 10.1.100.181:22 0.0.0.0:* LISTEN 900/sshd tcp 0 0 127.0.0.1:6010 0.0.0.0:* LISTEN 17361/sshd: rebermi tcp 0 64 10.1.100.181:22 10.224.204.222:31477 ESTABLISHED 17358/sshd: rebermi tcp 0 0 10.1.100.181:47656 172.27.130.12:61613 ESTABLISHED 17664/ruby tcp 0 0 10.1.100.181:43540 172.27.49.65:9997 ESTABLISHED 15129/splunkd tcp6 0 0 :::9000 :::* LISTEN 29798/nsrexecd tcp6 0 0 :::111 :::* LISTEN 1/systemd tcp6 0 0 :::9269 :::* LISTEN 29798/nsrexecd tcp6 0 0 ::1:6010 :::* LISTEN 17361/sshd: rebermi tcp6 0 0 :::7937 :::* LISTEN 29798/nsrexecd tcp6 0 0 :::7938 :::* LISTEN 29798/nsrexecd udp 0 0 0.0.0.0:111 0.0.0.0:* 6061/rpcbind udp 0 0 10.1.100.181:123 0.0.0.0:* 26924/ntpd udp 0 0 127.0.0.1:123 0.0.0.0:* 26924/ntpd udp 0 0 0.0.0.0:123 0.0.0.0:* 26924/ntpd udp 0 0 0.0.0.0:724 0.0.0.0:* 6061/rpcbind udp6 0 0 :::111 :::* 6061/rpcbind udp6 0 0 ::1:123 :::* 26924/ntpd udp6 0 0 :::123 :::* 26924/ntpd udp6 0 0 :::724 :::* 6061/rpcbind udp6 0 0 :::7938 :::* 29798/nsrexecd Active UNIX domain sockets (servers and established) Proto RefCnt Flags Type State I-Node PID/Program name Path unix 2 [ ACC ] STREAM LISTENING 11522 1/systemd /run/lvm/lvmetad.socket unix 2 [ ACC ] STREAM LISTENING 11275 1/systemd /run/systemd/private unix 2 [ ACC ] STREAM LISTENING 14389 649/gssproxy /run/gssproxy.sock unix 2 [ ACC ] STREAM LISTENING 30777543 17361/sshd: rebermi /tmp/ssh-v94wMvs2vd/agent.17361 unix 2 [ ACC ] STREAM LISTENING 14191 1/systemd /var/run/dbus/system_bus_socket unix 2 [ ACC ] STREAM LISTENING 14388 649/gssproxy /var/lib/gssproxy/default.sock unix 2 [ ACC ] STREAM LISTENING 14194 1/systemd /var/run/rpcbind.sock unix 2 [ ] DGRAM 6831 1/systemd /run/systemd/notify unix 2 [ ] DGRAM 6833 1/systemd /run/systemd/cgroups-agent unix 2 [ ACC ] STREAM LISTENING 6842 1/systemd /run/systemd/journal/stdout unix 2 [ ACC ] STREAM LISTENING 11451 1/systemd /run/lvm/lvmpolld.socket unix 5 [ ] DGRAM 6845 1/systemd /run/systemd/journal/socket unix 9 [ ] DGRAM 6847 1/systemd /dev/log unix 2 [ ] DGRAM 11466 1/systemd /run/systemd/shutdownd unix 2 [ ACC ] SEQPACKET LISTENING 11518 1/systemd /run/udev/control unix 2 [ ] DGRAM 14377 649/gssproxy unix 3 [ ] DGRAM 12481 494/systemd-udevd unix 3 [ ] STREAM CONNECTED 14366 459/systemd-journal /run/systemd/journal/stdout unix 3 [ ] DGRAM 12480 494/systemd-udevd unix 2 [ ] DGRAM 12461 494/systemd-udevd unix 3 [ ] STREAM CONNECTED 14365 647/dbus-daemon unix 2 [ ] DGRAM 30777608 17397/sudo unix 3 [ ] STREAM CONNECTED 14402 647/dbus-daemon unix 3 [ ] STREAM CONNECTED 14102 626/auditd unix 3 [ ] STREAM CONNECTED 14258 459/systemd-journal /run/systemd/journal/stdout unix 2 [ ] DGRAM 25345848 647/dbus-daemon unix 3 [ ] STREAM CONNECTED 12107 481/lvmetad unix 3 [ ] STREAM CONNECTED 2557415 459/systemd-journal /run/systemd/journal/stdout unix 3 [ ] STREAM CONNECTED 25694704 15129/splunkd unix 3 [ ] STREAM CONNECTED 2557414 29726/crond unix 2 [ ] DGRAM 15260 662/polkitd unix 2 [ ] DGRAM 27844357 26924/ntpd unix 3 [ ] DGRAM 25694716 15134/[splunkd pid= unix 3 [ ] STREAM CONNECTED 14376 1/systemd unix 3 [ ] STREAM CONNECTED 14758 661/systemd-logind unix 3 [ ] STREAM CONNECTED 14393 - unix 3 [ ] STREAM CONNECTED 14759 459/systemd-journal /run/systemd/journal/stdout unix 3 [ ] STREAM CONNECTED 14404 647/dbus-daemon /var/run/dbus/system_bus_socket unix 3 [ ] DGRAM 25694715 15129/splunkd unix 3 [ ] STREAM CONNECTED 16427 459/systemd-journal /run/systemd/journal/stdout unix 2 [ ] DGRAM 14793 661/systemd-logind unix 3 [ ] STREAM CONNECTED 25694714 15134/[splunkd pid= unix 2 [ ] DGRAM 2557417 29726/crond unix 3 [ ] STREAM CONNECTED 25694713 15129/splunkd unix 3 [ ] STREAM CONNECTED 25694705 15129/splunkd unix 3 [ ] STREAM CONNECTED 14395 649/gssproxy /run/gssproxy.sock unix 3 [ ] STREAM CONNECTED 12108 459/systemd-journal /run/systemd/journal/stdout unix 3 [ ] STREAM CONNECTED 18263 893/python unix 3 [ ] STREAM CONNECTED 30777525 17361/sshd: rebermi unix 3 [ ] STREAM CONNECTED 18264 647/dbus-daemon /var/run/dbus/system_bus_socket unix 3 [ ] STREAM CONNECTED 14812 661/systemd-logind unix 2 [ ] DGRAM 30777518 17358/sshd: rebermi unix 3 [ ] STREAM CONNECTED 14101 626/auditd unix 3 [ ] STREAM CONNECTED 30777526 17358/sshd: rebermi unix 2 [ ] DGRAM 14100 626/auditd unix 3 [ ] STREAM CONNECTED 14403 647/dbus-daemon unix 3 [ ] STREAM CONNECTED 14257 649/gssproxy unix 3 [ ] STREAM CONNECTED 14813 647/dbus-daemon /var/run/dbus/system_bus_socket unix 3 [ ] STREAM CONNECTED 16426 900/sshd unix 3 [ ] STREAM CONNECTED 16106 893/python unix 3 [ ] STREAM CONNECTED 12451 494/systemd-udevd unix 3 [ ] STREAM CONNECTED 15061 647/dbus-daemon /var/run/dbus/system_bus_socket unix 3 [ ] STREAM CONNECTED 12452 459/systemd-journal /run/systemd/journal/stdout unix 2 [ ] DGRAM 29758906 1/systemd unix 3 [ ] STREAM CONNECTED 16107 459/systemd-journal /run/systemd/journal/stdout unix 3 [ ] STREAM CONNECTED 15060 662/polkitd
Show Installed Packages
# rpm -qa
pyserial-2.6-6.el7.noarch libblkid-2.23.2-43.el7.x86_64 tfm-rubygem-rails-i18n-4.0.8-1.el7sat.noarch basesystem-10.0-7.el7.noarch pulp-selinux-2.8.7.14-1.el7sat.noarch gawk-4.0.2-4.el7_3.1.x86_64 tfm-rubygem-sprockets-rails-2.3.3-1.el7sat.noarch libsndfile-1.0.25-10.el7.x86_64 libsemanage-2.5-8.el7.x86_64 tfm-rubygem-highline-1.6.21-4.el7sat.noarch rubygem-bundler_ext-0.3.0-7.el7sat.noarch fuse-2.9.2-8.el7.x86_64 tfm-rubygem-will_paginate-3.0.7-1.el7sat.noarch popt-1.13-16.el7.x86_64 cairo-1.14.8-2.el7.x86_64 libmspack-0.5-0.5.alpha.el7.x86_64 tfm-rubygem-trollop-2.0-5.el7sat.noarch libcap-ng-0.7.5-4.el7.x86_64 geronimo-jms-1.1.1-19.el7.noarch python-libs-2.7.5-58.el7.x86_64 tfm-rubygem-facter-2.4.0-3.el7sat.x86_64 findutils-4.5.11-5.el7.x86_64 apache-commons-logging-1.1.2-7.el7.noarch openldap-2.4.44-5.el7.x86_64 tfm-rubygem-awesome_print-1.0.2-13.el7sat.noarch tomcat-7.0.76-2.el7.noarch ruby-2.0.0.648-30.el7.x86_64 tfm-rubygem-formatador-0.2.1-9.el7sat.noarch unzip-6.0-16.el7.x86_64 fuse-libs-2.9.2-8.el7.x86_64 tfm-rubygem-fog-vsphere-0.6.3-1.el7sat.noarch qrencode-libs-3.4.1-3.el7.x86_64 openssl-1.0.2k-8.el7.x86_64 redhat-release-server-7.4-18.el7.x86_64 tfm-rubygem-activerecord-session_store-0.1.2-1.el7sat.noarch cracklib-2.9.0-11.el7.x86_64 python-pulp-oid_validation-2.8.7.14-1.el7sat.noarch libcgroup-0.41-13.el7.x86_64 tfm-rubygem-hammer_cli_katello-0.0.22.29-1.el7sat.noarch libutempter-1.1.6-4.el7.x86_64 puppet-3.8.6-2.el7sat.noarch setroubleshoot-plugins-3.0.65-1.el7.noarch tfm-rubygem-ancestry-2.0.0-4.el7sat.noarch ..
Show Contents of one Installed Package
rpm -ql PACKAGENAME
# rpm -ql httpd
/etc/httpd /etc/httpd/conf /etc/httpd/conf.d /etc/httpd/conf.d/README /etc/httpd/conf.d/autoindex.conf /etc/httpd/conf.d/userdir.conf /etc/httpd/conf.d/welcome.conf /etc/httpd/conf.modules.d /etc/httpd/conf.modules.d/00-base.conf /etc/httpd/conf.modules.d/00-dav.conf /etc/httpd/conf.modules.d/00-lua.conf /etc/httpd/conf.modules.d/00-mpm.conf /etc/httpd/conf.modules.d/00-proxy.conf /etc/httpd/conf.modules.d/00-systemd.conf /etc/httpd/conf.modules.d/01-cgi.conf /etc/httpd/conf/httpd.conf /etc/httpd/conf/magic /etc/httpd/logs /etc/httpd/modules /etc/httpd/run /etc/logrotate.d/httpd /etc/sysconfig/htcacheclean /etc/sysconfig/httpd /run/httpd /run/httpd/htcacheclean /usr/lib/systemd/system/htcacheclean.service /usr/lib/systemd/system/httpd.service /usr/lib/tmpfiles.d/httpd.conf /usr/lib64/httpd /usr/lib64/httpd/modules /usr/lib64/httpd/modules/mod_access_compat.so /usr/lib64/httpd/modules/mod_actions.so /usr/lib64/httpd/modules/mod_alias.so /usr/lib64/httpd/modules/mod_allowmethods.so /usr/lib64/httpd/modules/mod_asis.so ..