Kā pārvaldīt Systemd pakalpojumus un vienības, izmantojot Linux
Systemctl ir systemd utilīta, kas ir atbildīga par systemd sistēmas un pakalpojumu pārvaldnieka kontroli. Systemd ir sistēmas pārvaldības dēmonu, utilītu un bibliotēku kolekcija, kas kalpo kā System V init dēmona aizstājēja. Systemd darbojas kā centrālā vadības un konfigurācijas platforma UNIX līdzīgai sistēmai.
Linux sistēmā Ecosystem Systemd ir ieviests lielākajā daļā standarta Linux izplatīšanas ar dažiem izņēmumiem. Systemd ir visu citu dēmonu vecāku process bieži, bet ne vienmēr.
Šī raksta mērķis ir uzzināt vairāk par to, kā vadīt sistēmu un pakalpojumus sistēmā, kurā darbojas sistēmad.
Sākot ar Systemtd un Systemctl Basics
1. Vispirms pārbaudiet, vai systemd ir instalēts jūsu sistēmā, vai nav, un kāda ir pašreiz instalētās Systemd versija?
# systemctl --version systemd 215 +PAM +AUDIT +SELINUX +IMA +SYSVINIT +LIBCRYPTSETUP +GCRYPT +ACL +XZ -SECCOMP -APPARMOR
No iepriekš minētā piemēra ir skaidrs, ka mums ir instalēta sistēmas 215 versija.
2. Pārbaudiet, kur ir instalēti sistēmasd un systemctl binārie faili un bibliotēkas.
# whereis systemd systemd: /usr/lib/systemd /etc/systemd /usr/share/systemd /usr/share/man/man1/systemd.1.gz # whereis systemctl systemctl: /usr/bin/systemctl /usr/share/man/man1/systemctl.1.gz
3. Pārbaudiet, vai systemd darbojas vai nē.
# ps -eaf | grep [s]ystemd root 1 0 0 16:27 ? 00:00:00 /usr/lib/systemd/systemd --switched-root --system --deserialize 23 root 444 1 0 16:27 ? 00:00:00 /usr/lib/systemd/systemd-journald root 469 1 0 16:27 ? 00:00:00 /usr/lib/systemd/systemd-udevd root 555 1 0 16:27 ? 00:00:00 /usr/lib/systemd/systemd-logind dbus 556 1 0 16:27 ? 00:00:00 /bin/dbus-daemon --system --address=systemd: --nofork --nopidfile --systemd-activation
Piezīme: systemd darbojas kā vecāku dēmons (PID = 1). Iepriekš norādītajā komandā ps ar (-e) atlasiet visus procesus, (-a) atlasiet visus procesus, izņemot sesiju vadītājus un (-f) pilnā formāta sarakstā (t.i., -eaf).
Ievērojiet arī kvadrātveida iekavas iepriekš minētajā piemērā un pārējos piemērus, kas jāievēro. Kvadrātiekavas izteiksme ir daļa no grep rakstzīmju klases modeļu saskaņošanas.
4. Analizējiet sistēmas palaišanas procesu.
# systemd-analyze Startup finished in 487ms (kernel) + 2.776s (initrd) + 20.229s (userspace) = 23.493s
5. Analizējiet katra procesa laiku sāknēšanas laikā.
# systemd-analyze blame 8.565s mariadb.service 7.991s webmin.service 6.095s postfix.service 4.311s httpd.service 3.926s firewalld.service 3.780s kdump.service 3.238s tuned.service 1.712s network.service 1.394s lvm2-monitor.service 1.126s systemd-logind.service ....
6. Analizējiet kritisko ķēdi sāknēšanas laikā.
# systemd-analyze critical-chain
The time after the unit is active or started is printed after the "@" character.
The time the unit takes to start is printed after the "+" character.
multi-user.target @20.222s
└─mariadb.service @11.657s +8.565s
└─network.target @11.168s
└─network.service @9.456s +1.712s
└─NetworkManager.service @8.858s +596ms
└─firewalld.service @4.931s +3.926s
└─basic.target @4.916s
└─sockets.target @4.916s
└─dbus.socket @4.916s
└─sysinit.target @4.905s
└─systemd-update-utmp.service @4.864s +39ms
└─auditd.service @4.563s +301ms
└─systemd-tmpfiles-setup.service @4.485s +69ms
└─rhel-import-state.service @4.342s +142ms
└─local-fs.target @4.324s
└─boot.mount @4.286s +31ms
└─[email \x2duuid-79f594ad\x2da332\x2d4730\x2dbb5f\x2d85d19608096
└─dev-disk-by\x2duuid-79f594ad\x2da332\x2d4730\x2dbb5f\x2d85d196080964.device @4
Svarīgi: Systemctl kā vienības pieņem pakalpojumus (.service), stiprinājuma punktu (.mount), kontaktligzdas (.socket) un ierīces (.device).
7. Uzskaitiet visas pieejamās vienības.
# systemctl list-unit-files UNIT FILE STATE proc-sys-fs-binfmt_misc.automount static dev-hugepages.mount static dev-mqueue.mount static proc-sys-fs-binfmt_misc.mount static sys-fs-fuse-connections.mount static sys-kernel-config.mount static sys-kernel-debug.mount static tmp.mount disabled brandbot.path disabled .....
8. Uzskaitiet visas darbojošās vienības.
# systemctl list-units UNIT LOAD ACTIVE SUB DESCRIPTION proc-sys-fs-binfmt_misc.automount loaded active waiting Arbitrary Executable File Formats File Syste sys-devices-pc...0-1:0:0:0-block-sr0.device loaded active plugged VBOX_CD-ROM sys-devices-pc...:00:03.0-net-enp0s3.device loaded active plugged PRO/1000 MT Desktop Adapter sys-devices-pc...00:05.0-sound-card0.device loaded active plugged 82801AA AC'97 Audio Controller sys-devices-pc...:0:0-block-sda-sda1.device loaded active plugged VBOX_HARDDISK sys-devices-pc...:0:0-block-sda-sda2.device loaded active plugged LVM PV Qzyo3l-qYaL-uRUa-Cjuk-pljo-qKtX-VgBQ8 sys-devices-pc...0-2:0:0:0-block-sda.device loaded active plugged VBOX_HARDDISK sys-devices-pl...erial8250-tty-ttyS0.device loaded active plugged /sys/devices/platform/serial8250/tty/ttyS0 sys-devices-pl...erial8250-tty-ttyS1.device loaded active plugged /sys/devices/platform/serial8250/tty/ttyS1 sys-devices-pl...erial8250-tty-ttyS2.device loaded active plugged /sys/devices/platform/serial8250/tty/ttyS2 sys-devices-pl...erial8250-tty-ttyS3.device loaded active plugged /sys/devices/platform/serial8250/tty/ttyS3 sys-devices-virtual-block-dm\x2d0.device loaded active plugged /sys/devices/virtual/block/dm-0 sys-devices-virtual-block-dm\x2d1.device loaded active plugged /sys/devices/virtual/block/dm-1 sys-module-configfs.device loaded active plugged /sys/module/configfs ...
9. Uzskaitiet visas neizdevušās vienības.
# systemctl --failed UNIT LOAD ACTIVE SUB DESCRIPTION kdump.service loaded failed failed Crash recovery kernel arming LOAD = Reflects whether the unit definition was properly loaded. ACTIVE = The high-level unit activation state, i.e. generalization of SUB. SUB = The low-level unit activation state, values depend on unit type. 1 loaded units listed. Pass --all to see loaded but inactive units, too. To show all installed unit files use 'systemctl list-unit-files'.
10. Pārbaudiet, vai ir iespējota vienība (cron.service)?
# systemctl is-enabled crond.service enabled
11. Pārbaudiet, vai darbojas kāda vienība vai pakalpojums?
# systemctl status firewalld.service
firewalld.service - firewalld - dynamic firewall daemon
Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled)
Active: active (running) since Tue 2015-04-28 16:27:55 IST; 34min ago
Main PID: 549 (firewalld)
CGroup: /system.slice/firewalld.service
└─549 /usr/bin/python -Es /usr/sbin/firewalld --nofork --nopid
Apr 28 16:27:51 tecmint systemd[1]: Starting firewalld - dynamic firewall daemon...
Apr 28 16:27:55 tecmint systemd[1]: Started firewalld - dynamic firewall daemon.
Pakalpojumu vadība un pārvaldība, izmantojot Systemctl
12. Uzskaitiet visus pakalpojumus (ieskaitot iespējotos un atspējotos).
# systemctl list-unit-files --type=service UNIT FILE STATE arp-ethers.service disabled auditd.service enabled [email disabled blk-availability.service disabled brandbot.service static collectd.service disabled console-getty.service disabled console-shell.service disabled cpupower.service disabled crond.service enabled dbus-org.fedoraproject.FirewallD1.service enabled ....
13. Kā es varu sākt, restartēt, apturēt, atkārtoti ielādēt un pārbaudīt pakalpojuma (httpd.service) statusu Linux.
# systemctl start httpd.service
# systemctl restart httpd.service
# systemctl stop httpd.service
# systemctl reload httpd.service
# systemctl status httpd.service
httpd.service - The Apache HTTP Server
Loaded: loaded (/usr/lib/systemd/system/httpd.service; enabled)
Active: active (running) since Tue 2015-04-28 17:21:30 IST; 6s ago
Process: 2876 ExecStop=/bin/kill -WINCH ${MAINPID} (code=exited, status=0/SUCCESS)
Main PID: 2881 (httpd)
Status: "Processing requests..."
CGroup: /system.slice/httpd.service
├─2881 /usr/sbin/httpd -DFOREGROUND
├─2884 /usr/sbin/httpd -DFOREGROUND
├─2885 /usr/sbin/httpd -DFOREGROUND
├─2886 /usr/sbin/httpd -DFOREGROUND
├─2887 /usr/sbin/httpd -DFOREGROUND
└─2888 /usr/sbin/httpd -DFOREGROUND
Apr 28 17:21:30 tecmint systemd[1]: Starting The Apache HTTP Server...
Apr 28 17:21:30 tecmint httpd[2881]: AH00558: httpd: Could not reliably determine the server's fully q...ssage
Apr 28 17:21:30 tecmint systemd[1]: Started The Apache HTTP Server.
Hint: Some lines were ellipsized, use -l to show in full.
Piezīme: Kad mēs izmantojam tādas komandas kā start, restart, stop un restoad with systemctl, mēs nesaņemsim nevienu izvadi terminālā, vienīgā statusa komanda izdrukās izvadi.
14. Kā aktivizēt pakalpojumu un iespējot vai atspējot pakalpojumu sāknēšanas laikā (automātiskās palaišanas pakalpojums sistēmas sāknēšanas laikā).
# systemctl is-active httpd.service # systemctl enable httpd.service # systemctl disable httpd.service
15. Kā maskēt (padarot neiespējamu palaišanu) vai atmaskot pakalpojumu (httpd.service).
# systemctl mask httpd.service ln -s '/dev/null' '/etc/systemd/system/httpd.service' # systemctl unmask httpd.service rm '/etc/systemd/system/httpd.service'
16. Kā nogalināt pakalpojumu, izmantojot komandu systemctl.
# systemctl kill httpd # systemctl status httpd httpd.service - The Apache HTTP Server Loaded: loaded (/usr/lib/systemd/system/httpd.service; enabled) Active: failed (Result: exit-code) since Tue 2015-04-28 18:01:42 IST; 28min ago Main PID: 2881 (code=exited, status=0/SUCCESS) Status: "Total requests: 0; Current requests/sec: 0; Current traffic: 0 B/sec" Apr 28 17:37:29 tecmint systemd[1]: httpd.service: Got notification message from PID 2881, but recepti...bled. Apr 28 17:37:29 tecmint systemd[1]: httpd.service: Got notification message from PID 2881, but recepti...bled. Apr 28 17:37:39 tecmint systemd[1]: httpd.service: Got notification message from PID 2881, but recepti...bled. Apr 28 17:37:39 tecmint systemd[1]: httpd.service: Got notification message from PID 2881, but recepti...bled. Apr 28 17:37:49 tecmint systemd[1]: httpd.service: Got notification message from PID 2881, but recepti...bled. Apr 28 17:37:49 tecmint systemd[1]: httpd.service: Got notification message from PID 2881, but recepti...bled. Apr 28 17:37:59 tecmint systemd[1]: httpd.service: Got notification message from PID 2881, but recepti...bled. Apr 28 17:37:59 tecmint systemd[1]: httpd.service: Got notification message from PID 2881, but recepti...bled. Apr 28 18:01:42 tecmint systemd[1]: httpd.service: control process exited, code=exited status=226 Apr 28 18:01:42 tecmint systemd[1]: Unit httpd.service entered failed state. Hint: Some lines were ellipsized, use -l to show in full.
Kontrolējiet un pārvaldiet stiprinājuma punktus, izmantojot Systemctl
17. Uzskaitiet visus sistēmas stiprināšanas punktus.
# systemctl list-unit-files --type=mount UNIT FILE STATE dev-hugepages.mount static dev-mqueue.mount static proc-sys-fs-binfmt_misc.mount static sys-fs-fuse-connections.mount static sys-kernel-config.mount static sys-kernel-debug.mount static tmp.mount disabled
18. Kā es varu uzstādīt, atvienot, no jauna uzstādīt, atkārtoti ielādēt sistēmas stiprināšanas punktus un arī pārbaudīt pievienošanas punktu statusu sistēmā?
# systemctl start tmp.mount
# systemctl stop tmp.mount
# systemctl restart tmp.mount
# systemctl reload tmp.mount
# systemctl status tmp.mount
tmp.mount - Temporary Directory
Loaded: loaded (/usr/lib/systemd/system/tmp.mount; disabled)
Active: active (mounted) since Tue 2015-04-28 17:46:06 IST; 2min 48s ago
Where: /tmp
What: tmpfs
Docs: man:hier(7)
http://www.freedesktop.org/wiki/Software/systemd/APIFileSystems
Process: 3908 ExecMount=/bin/mount tmpfs /tmp -t tmpfs -o mode=1777,strictatime (code=exited, status=0/SUCCESS)
Apr 28 17:46:06 tecmint systemd[1]: Mounting Temporary Directory...
Apr 28 17:46:06 tecmint systemd[1]: tmp.mount: Directory /tmp to mount over is not empty, mounting anyway.
Apr 28 17:46:06 tecmint systemd[1]: Mounted Temporary Directory.
19. Kā aktivizēt, iespējot vai atspējot pievienošanas punktu sāknēšanas laikā (automātiska pievienošana sistēmas sāknēšanas laikā).
# systemctl is-active tmp.mount # systemctl enable tmp.mount # systemctl disable tmp.mount
20. Kā maskēt (padarot neiespējamu startēšanu) vai demaskēt pievienošanas punktu Linux.
# systemctl mask tmp.mount ln -s '/dev/null' '/etc/systemd/system/tmp.mount' # systemctl unmask tmp.mount rm '/etc/systemd/system/tmp.mount'
Vadīt un pārvaldīt kontaktligzdas, izmantojot Systemctl
21. Uzskaitiet visas pieejamās sistēmas kontaktligzdas.
# systemctl list-unit-files --type=socket UNIT FILE STATE dbus.socket static dm-event.socket enabled lvm2-lvmetad.socket enabled rsyncd.socket disabled sshd.socket disabled syslog.socket static systemd-initctl.socket static systemd-journald.socket static systemd-shutdownd.socket static systemd-udevd-control.socket static systemd-udevd-kernel.socket static 11 unit files listed.
22. Kā es varu sākt, restartēt, apturēt, atkārtoti ielādēt un pārbaudīt ligzdas (piemēram: cups.socket) statusu Linux.
# systemctl start cups.socket # systemctl restart cups.socket # systemctl stop cups.socket # systemctl reload cups.socket # systemctl status cups.socket cups.socket - CUPS Printing Service Sockets Loaded: loaded (/usr/lib/systemd/system/cups.socket; enabled) Active: active (listening) since Tue 2015-04-28 18:10:59 IST; 8s ago Listen: /var/run/cups/cups.sock (Stream) Apr 28 18:10:59 tecmint systemd[1]: Starting CUPS Printing Service Sockets. Apr 28 18:10:59 tecmint systemd[1]: Listening on CUPS Printing Service Sockets.
23. Kā aktivizēt ligzdu un iespējot vai atspējot sāknēšanas laikā (automātiskās palaišanas ligzda sistēmas sāknēšanas laikā).
# systemctl is-active cups.socket # systemctl enable cups.socket # systemctl disable cups.socket
24. Kā maskēt (padarot neiespējamu iedarbināšanu) vai atmaskot kontaktligzdu (tases.ligzda).
# systemctl mask cups.socket ln -s '/dev/null' '/etc/systemd/system/cups.socket' # systemctl unmask cups.socket rm '/etc/systemd/system/cups.socket'