系统管理：
1、通过ps命令的两种选项形式查看进程信息
[root@localhost ~]# ps aux
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
root 1 0.0 0.3 60652 7916 ? Ss 01:07 0:03 /usr/lib/syste
root 2 0.0 0.0 0 0 ? S 01:07 0:00 [kthreadd]
root 3 0.0 0.0 0 0 ? S 01:07 0:04 [ksoftirqd/0]
root 5 0.0 0.0 0 0 ? S< 01:07 0:00 [kworker/0:0H]
root 7 0.0 0.0 0 0 ? S 01:07 0:00 [migration/0]
root 8 0.0 0.0 0 0 ? S 01:07 0:00 [rcu_bh]
root 9 0.0 0.0 0 0 ? S 01:07 0:00 [rcuob/0]
root 10 0.0 0.0 0 0 ? S 01:07 0:00 [rcuob/1]
root 11 0.0 0.0 0 0 ? S 01:07 0:00 [rcuob/2]
........
root 92001 0.0 0.0 22652 1956 ? Ss 10:43 0:00 /usr/lib/syste
root 92014 0.0 0.1 116248 2884 pts/0 Ss+ 10:43 0:00 /bin/bash
root 92055 0.2 0.2 135348 4904 ? Ss 10:44 0:00 sshd: root@pts
root 92059 0.0 0.1 116008 2760 pts/3 Ss 10:44 0:00 -bash
root 92099 0.0 0.0 107892 612 ? S 10:45 0:00 sleep 60
root 92100 0.0 0.0 123372 1396 pts/3 R+ 10:45 0:00 ps aux
[root@localhost ~]# ps -elf
F S UID PID PPID C PRI NI ADDR SZ WCHAN STIME TTY TIME CMD
4 S root 1 0 0 80 0 - 15163 ep_pol 01:07 ? 00:00:03 /us
1 S root 2 0 0 80 0 - 0 kthrea 01:07 ? 00:00:00 [kt
1 S root 3 2 0 80 0 - 0 smpboo 01:07 ? 00:00:04 [ks
1 S root 5 2 0 60 -20 - 0 worker 01:07 ? 00:00:00 [kw
1 S root 7 2 0 -40 - - 0 smpboo 01:07 ? 00:00:00 [mi
1 S root 8 2 0 80 0 - 0 rcu_gp 01:07 ? 00:00:00 [rc
1 S root 9 2 0 80 0 - 0 rcu_no 01:07 ? 00:00:00 [rc
1 S root 10 2 0 80 0 - 0 rcu_no 01:07 ? 00:00:00 [rc
1 S root 11 2 0 80 0 - 0 rcu_no 01:07 ? 00:00:00 [rc
.......
4 S root 92001 1 0 80 0 - 5663 poll_s 10:43 ? 00:00:00 /us
4 S root 92014 90177 0 80 0 - 29062 n_tty_ 10:43 pts/0 00:00:00 /bi
4 S root 92055 1407 0 80 0 - 33837 poll_s 10:44 ? 00:00:00 ssh
4 S root 92059 92055 0 80 0 - 29002 wait 10:44 pts/3 00:00:00 -ba
1 S root 92109 2 0 80 0 - 0 worker 10:46 ? 00:00:00 [kw
0 S root 92117 943 0 80 0 - 26973 hrtime 10:47 ? 00:00:00 sle
0 R root 92118 92059 0 80 0 - 30843 - 10:47 pts/3 00:00:00 ps
2、通过top命令查看进程
[root@localhost ~]# top
top - 10:50:12 up 9:42, 5 users, load average: 0.07, 0.09, 0.06
Tasks: 434 total, 3 running, 431 sleeping, 0 stopped, 0 zombie
%Cpu(s): 0.0 us, 0.3 sy, 0.0 ni, 99.7 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
KiB Mem : 2035352 total, 146668 free, 730760 used, 1157924 buff/cache
KiB Swap: 2097148 total, 2096660 free, 488 used. 1047584 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
883 root 20 0 269016 3612 2756 S 0.3 0.2 0:50.29 vmtoolsd
2264 root 20 0 343988 11944 8704 R 0.3 0.6 0:51.19 vmtoolsd
92138 root 20 0 130288 2116 1268 R 0.3 0.1 0:00.43 top
1 root 20 0 60652 7916 2536 S 0.0 0.4 0:03.15 systemd
2 root 20 0 0 0 0 S 0.0 0.0 0:00.05 kthreadd
3 root 20 0 0 0 0 S 0.0 0.0 0:04.68 ksoftirqd/0
5 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 kworker/0:0H
7 root rt 0 0 0 0 S 0.0 0.0 0:00.00 migration/0
8 root 20 0 0 0 0 S 0.0 0.0 0:00.00 rcu_bh
9 root 20 0 0 0 0 S 0.0 0.0 0:00.00 rcuob/0
10 root 20 0 0 0 0 S 0.0 0.0 0:00.00 rcuob/1
11 root 20 0 0 0 0 S 0.0 0.0 0:00.00 rcuob/2
12 root 20 0 0 0 0 S 0.0 0.0 0:00.00 rcuob/3
13 root 20 0 0 0 0 S 0.0 0.0 0:00.00 rcuob/4
14 root 20 0 0 0 0 S 0.0 0.0 0:00.00 rcuob/5
3、通过pgrep命令查看sshd服务的进程号
[root@localhost ~]# pgrep -l sshd
1407 sshd
90218 sshd
92055 sshd
4、查看系统进程树
[root@localhost ~]# pstree -aup
systemd,1 --switched-root --system --deserialize 21
├─ModemManager,897
│ ├─{ModemManager},927
│ └─{ModemManager},954
├─NetworkManager,1039 --no-daemon
│ ├─dhclient,90705 -d -q -sf /usr/libexec/nm-dhcp-helper -pf /var/run/dhclient-eno16777736.pid -lf...
│ ├─{NetworkManager},1057
│ ├─{NetworkManager},1059
│ └─{NetworkManager},1061
├─abrt-watch-log,889 -F BUG: WARNING: at WARNING: CPU: INFO: possible recursive locking detected ernel BUG at list_del corruption list_add corruption ...
├─abrt-watch-log,891 -F Backtrace /var/log/Xorg.0.log -- /usr/bin/abrt-dump-xorg -xD
├─abrtd,888 -d -s
├─accounts-daemon,920
│ ├─{accounts-daemon},931
│ └─{accounts-daemon},948
├─alsactl,878 -s -n 19 -c -E ALSA_CONFIG_PATH=/etc/alsa/alsactl.conf --initfile=/lib/alsa/init/00main rdaemon
├─at-spi-bus-laun,2037
│ ├─dbus-daemon,2041 --config-file=/etc/at-spi2/accessibility.conf --nofork --print-address 3
│ │ └─{dbus-daemon},2042
│ ├─{at-spi-bus-laun},2038
│ ├─{at-spi-bus-laun},2040
│ └─{at-spi-bus-laun},2043
├─at-spi2-registr,2046 --use-gnome-session
│ └─{at-spi2-registr},2049
├─atd,1416 -f
├─auditd,854 -n
│ ├─audispd,861
│ │ ├─sedispatch,865
│ │ └─{audispd},866
│ └─{auditd},860
├─avahi-daemon,900,avahi
│ └─avahi-daemon,915
├─bluetoothd,879 -n
├─chronyd,893,chrony -u chrony
├─colord,1779,colord
│ ├─{colord},1781
│ └─{colord},1783
├─crond,1415 -n
├─cupsd,2127 -f
├─dbus-daemon,1891 --fork --print-pid 4 --print-address 6 --session
│ └─{dbus-daemon},1892
├─dbus-daemon,924,dbus --system --address=systemd: --nofork --nopidfile --systemd-activation
│ └─{dbus-daemon},940
├─dbus-launch,1890 --sh-syntax --exit-with-session
├─dconf-service,2142
│ ├─{dconf-service},2145
│ └─{dconf-service},2146
├─evolution-addre,2221
│ ├─{evolution-addre},2226
│ ├─{evolution-addre},2244
│ ├─{evolution-addre},2251
│ └─{evolution-addre},2252
├─evolution-calen,2247
│ ├─{evolution-calen},2282
│ ├─{evolution-calen},2286
│ ├─{evolution-calen},2296
│ └─{evolution-calen},2297
├─evolution-sourc,2178
│ ├─{evolution-sourc},2179
│ └─{evolution-sourc},2188
├─gconfd-2,2219
├─gdm,1418
│ ├─gdm-simple-slav,1441 --display-id /org/gnome/DisplayManager/Displays/_0
│ │ ├─Xorg,1464 :0 -background none -verbose -auth /run/gdm/auth-for-gdm-z9CyMo/database -seat seat0 -nolisten tcp vt1
│ │ ├─gdm-session-wor,1871
│ │ │ ├─gdm-session-wor,89917
│ │ │ │ ├─{gdm-session-wor},89918
│ │ │ │ └─{gdm-session-wor},89920
│ │ │ ├─gnome-session,1882 --session gnome-classic
│ │ │ │ ├─abrt-applet,2276
│ │ │ │ │ └─{abrt-applet},2285
│ │ │ │ ├─gnome-settings-,2059
│ │ │ │ │ ├─{gnome-settings-},2067
│ │ │ │ │ ├─{gnome-settings-},2073
│ │ │ │ │ ├─{gnome-settings-},2078
│ │ │ │ │ └─{gnome-settings-},2084
│ │ │ │ ├─gnome-shell,2126
│ │ │ │ │ ├─{gnome-shell},2131
│ │ │ │ │ ├─{gnome-shell},2139
│ │ │ │ │ ├─{gnome-shell},2141
│ │ │ │ │ ├─{gnome-shell},2143
│ │ │ │ │ └─{gnome-shell},2165
│ │ │ │ ├─seapplet,2237
│ │ │ │ ├─ssh-agent,2025 /bin/sh -c exec -l /bin/bash -c "env GNOME_SHELL_SESSION_MODE=classic gnome-session --session gnome-classic"
│ │ │ │ ├─tracker-miner-f,2267
│ │ │ │ │ ├─{tracker-miner-f},2271
│ │ │ │ │ ├─{tracker-miner-f},2274
│ │ │ │ │ └─{tracker-miner-f},2278
│ │ │ │ ├─{gnome-session},2045
│ │ │ │ ├─{gnome-session},2047
│ │ │ │ └─{gnome-session},2048
│ │ │ ├─{gdm-session-wor},1872
│ │ │ └─{gdm-session-wor},1873
│ │ ├─{gdm-simple-slav},1453
│ │ └─{gdm-simple-slav},1456
│ ├─{gdm},1433
│ └─{gdm},1438
├─gnome-keyring-d,1880 --daemonize --login
│ ├─{gnome-keyring-d},1881
│ ├─{gnome-keyring-d},2069
│ ├─{gnome-keyring-d},2071
│ └─{gnome-keyring-d},2075
├─gnome-shell-cal,2167
│ ├─{gnome-shell-cal},2172
│ ├─{gnome-shell-cal},2173
│ ├─{gnome-shell-cal},2174
│ └─{gnome-shell-cal},2235
├─gnome-terminal-,90177
│ ├─bash,90184
│ ├─bash,92014
│ ├─gnome-pty-helpe,90183
│ ├─{gnome-terminal-},90178
│ ├─{gnome-terminal-},90179
│ └─{gnome-terminal-},90180
├─goa-daemon,2108
│ ├─{goa-daemon},2109
│ ├─{goa-daemon},2111
│ └─{goa-daemon},2112
├─goa-identity-se,2116
│ ├─{goa-identity-se},2119
│ └─{goa-identity-se},2123
├─gsd-printer,2133
│ └─{gsd-printer},2136
├─gvfs-afc-volume,2118
│ ├─{gvfs-afc-volume},2120
│ └─{gvfs-afc-volume},2122
├─gvfs-goa-volume,2105
│ └─{gvfs-goa-volume},2106
├─gvfs-gphoto2-vo,2097
│ └─{gvfs-gphoto2-vo},2099
├─gvfs-mtp-volume,2101
│ └─{gvfs-mtp-volume},2103
├─gvfs-udisks2-vo,2086
│ ├─{gvfs-udisks2-vo},2087
│ └─{gvfs-udisks2-vo},2094
├─gvfsd,1946
│ └─{gvfsd},1947
├─gvfsd-burn,2284 --spawner :1.3 /org/gtk/gvfs/exec_spaw/1
│ └─{gvfsd-burn},2295
├─gvfsd-fuse,1955 /run/user/0/gvfs -f -o big_writes
│ ├─{gvfsd-fuse},1965
│ ├─{gvfsd-fuse},1969
│ ├─{gvfsd-fuse},1971
│ └─{gvfsd-fuse},1974
├─gvfsd-trash,2242 --spawner :1.3 /org/gtk/gvfs/exec_spaw/0
│ ├─{gvfsd-trash},2250
│ └─{gvfsd-trash},2259
├─httpd,89753 -k start
│ ├─httpd,89754,daemon -k start
│ ├─httpd,89755,daemon -k start
│ ├─httpd,89756,daemon -k start
│ ├─httpd,89757,daemon -k start
│ └─httpd,89758,daemon -k start
├─ibus-daemon,2149 --replace --xim --panel disable
│ ├─ibus-dconf,2153
│ │ ├─{ibus-dconf},2155
│ │ ├─{ibus-dconf},2157
│ │ └─{ibus-dconf},2159
│ ├─ibus-engine-sim,2215
│ │ ├─{ibus-engine-sim},2220
│ │ └─{ibus-engine-sim},2223
│ ├─{ibus-daemon},2150
│ └─{ibus-daemon},2151
├─ibus-x11,2156 --kill-daemon
│ ├─{ibus-x11},2160
│ └─{ibus-x11},2164
├─ksmtuned,943 /usr/sbin/ksmtuned
│ └─sleep,92249 60
├─libvirtd,1405
│ ├─{libvirtd},1422
│ ├─{libvirtd},1423
│ ├─{libvirtd},1424
│ ├─{libvirtd},1425
│ ├─{libvirtd},1426
│ ├─{libvirtd},1427
│ ├─{libvirtd},1428
│ ├─{libvirtd},1429
│ ├─{libvirtd},1430
│ └─{libvirtd},1431
├─lsmd,882,libstoragemgmt -d
├─lvmetad,740 -f
├─master,1624 -w
│ ├─pickup,91699,postfix -l -t unix -u
│ └─qmgr,1627,postfix -l -t unix -u
├─mission-control,2169
│ ├─{mission-control},2175
│ └─{mission-control},2176
├─nautilus,2186 --no-default-window
│ ├─{nautilus},2200
│ ├─{nautilus},2209
│ └─{nautilus},2222
├─nm-dispatcher,92222
│ ├─{nm-dispatcher},92223
│ └─{nm-dispatcher},92224
├─polkitd,955,polkitd --no-debug
│ ├─{polkitd},968
│ ├─{polkitd},969
│ ├─{polkitd},970
│ ├─{polkitd},971
│ └─{polkitd},972
├─pulseaudio,2065 --start
│ ├─{pulseaudio},2070
│ └─{pulseaudio},2072
├─rngd,906 -f
├─rsyslogd,895 -n
│ ├─{rsyslogd},917
│ └─{rsyslogd},918
├─rtkit-daemon,923,rtkit
│ ├─{rtkit-daemon},951
│ └─{rtkit-daemon},952
├─smartd,910 -n -q never
├─sshd,1407 -D
│ ├─sshd,90218
│ │ └─bash,90222
│ └─sshd,92055
│ └─bash,92059
│ └─pstree,92250 -aup
├─systemd-journal,734
├─systemd-logind,914
├─systemd-udevd,746
├─tracker-store,2241
│ ├─{tracker-store},2248
│ ├─{tracker-store},2249
│ ├─{tracker-store},2253
│ ├─{tracker-store},2254
│ ├─{tracker-store},2255
│ ├─{tracker-store},2256
│ └─{tracker-store},2257
├─tuned,896 -Es /usr/sbin/tuned -l -P
│ ├─{tuned},986
│ ├─{tuned},987
│ ├─{tuned},991
│ └─{tuned},993
├─udisksd,2088 --no-debug
│ ├─{udisksd},2089
│ ├─{udisksd},2091
│ ├─{udisksd},2092
│ └─{udisksd},2093
├─upowerd,1720
│ ├─{upowerd},1722
│ └─{upowerd},1723
├─vmtoolsd,883
│ └─{vmtoolsd},937
└─vmtoolsd,2264 -n vmusr
5、使dd if=/dev/zero of=/root/file bs=1M count=8190 命令操作在前台运行
[root@localhost ~]# dd if=/dev/zero of=/root/file bs=1M count=8190
6、将第5题命令操作调入到后台并暂停
^Z
[1]+ 已停止 dd if=/dev/zero of=/root/file bs=1M count=8190
7、使dd if=/dev/zero of=/root/file2 bs=1M count=1024 命令操作在后台运行
[root@localhost ~]# dd if=/dev/zero of=/root/file2 bs=1M count=1024 &
[2] 92387
8、查看后台的任务列表
[root@localhost ~]# jobs -l
[1]+ 92317 停止 dd if=/dev/zero of=/root/file bs=1M count=8190
[2]- 92387 运行中 dd if=/dev/zero of=/root/file2 bs=1M count=1024 &
[root@localhost ~]# 记录了1024+0 的读入
记录了1024+0 的写出
1073741824字节(1.1 GB)已复制，5.4253 秒，198 MB/秒
[2]- 完成 dd if=/dev/zero of=/root/file2 bs=1M count=1024
9、恢复dd if=/dev/zero of=/root/file bs=1M count=8190 让其在后台继续运行
[root@localhost ~]# bg 1
[1]+ dd if=/dev/zero of=/root/file bs=1M count=8190 &
[root@localhost ~]# 记录了8190+0 的读入
记录了8190+0 的写出
8587837440字节(8.6 GB)已复制，495.078 秒，17.3 MB/秒
[1]+ 完成 dd if=/dev/zero of=/root/file bs=1M count=8190
10、查询dd if=/dev/zero of=/root/file bs=1M count=8190 命令的进程并通过kill杀死
[root@localhost ~]# dd if=/dev/zero of=/root/file bs=1M count=819000
[root@localhost ~]# ps aux |grep dd
root 92453 14.6 0.0 108956 1672 pts/3 D+ 11:12 0:20 dd if=/dev/zero of=/root/file bs=1M count=819000
[root@localhost ~]# kill -9 92453
[root@localhost ~]# dd if=/dev/zero of=/root/file bs=1M count=819000
已杀死
11、设置一次性计划任务在18：00时关闭系统，并查看任务信息
[root@localhost ~]# service atd status
Redirecting to /bin/systemctl status atd.service
atd.service - Job spooling tools
Loaded: loaded (/usr/lib/systemd/system/atd.service; enabled)
Active: active (running) since 五 2019-08-02 12:10:52 CST; 5 days ago
Main PID: 1416 (atd)
CGroup: /system.slice/atd.service
└─1416 /usr/sbin/atd -f
8月 02 12:10:52 localhost.localdomain systemd[1]: Starting Job spooling tool...
8月 02 12:10:52 localhost.localdomain systemd[1]: Started Job spooling tools.
Hint: Some lines were ellipsized, use -l to show in full.
[root@localhost ~]# at 18:00 2019-8-8
at> init 0
at> <EOT>
job 2 at Thu Aug 8 18:00:00 2019
[root@localhost ~]# atq
2 Thu Aug 8 18:00:00 2019 a root
[root@localhost ~]# atrm 2
[root@localhost ~]# atq
12、以root身份设置周期性计划任务
a) 每天晚上的24点时打包压缩 /etc/passwd /etc/shadow /etc/group /etc/gshadow 为 file.tar.gz
b) 每周一的每隔五分钟列出磁盘使用状况
c) 每天的8:30与互联网时间同步服务器pool.ntp.org同步时间
[root@localhost ~]# crontab -e
no crontab for root - using an empty one
0 0 * * * tar -zcf file.tar.gz /etc/passwd /etc/shadow /etc/group /etc/gshadow
*/5 * * * 1 df -i /dev/sd*
30 8 * * * ntpdate pool.ntp.org
13、通过crontab命令查看root的计划任务，通过文件查看类工具列出/var/spool/cron下对应的文件内容
[root@localhost ~]# crontab -l
0 0 * * * tar -zcf file.tar.gz /etc/passwd /etc/shadow /etc/group /etc/gshadow
*/5 * * * 1 df -i /dev/sd*
30 8 * * * ntpdate pool.ntp.org
[root@localhost ~]# cat /var/spool/cron/root
0 0 * * * tar -zcf file.tar.gz /etc/passwd /etc/shadow /etc/group /etc/gshadow
*/5 * * * 1 df -i /dev/sd*
30 8 * * * ntpdate pool.ntp.org