1.查看内存使用情况：
[root@takeout web-takeout]# free -m
total used free shared buff/cache available
Mem: 3788 1358 1096 17 1333 1886
Swap: 3967 17 3950
[root@takeout web-takeout]#
2.详细列出的进程情况，重点关注第10列内存使用占比：
top - 15:36:09 up 8 days, 5:07, 2 users, load average: 0.01, 0.02, 0.05
Tasks: 330 total, 1 running, 329 sleeping, 0 stopped, 0 zombie
%Cpu(s): 0.3 us, 1.3 sy, 0.0 ni, 98.3 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
KiB Mem : 3879356 total, 1122336 free, 1391484 used, 1365536 buff/cache
KiB Swap: 4063228 total, 4045192 free, 18036 used. 1931104 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
22388 root 20 0 160080 2448 1532 R 11.8 0.1 0:00.03 top
7743 systemd+ 20 0 343652 88800 13740 S 5.9 2.3 145:50.06 mongod
1 root 20 0 191776 4560 2520 S 0.0 0.1 0:31.86 systemd
2 root 20 0 0 0 0 S 0.0 0.0 0:00.19 kthreadd
3 root 20 0 0 0 0 S 0.0 0.0 0:12.19 ksoftirqd/0
5 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 kworker/0:0H
6 root 20 0 0 0 0 S 0.0 0.0 0:24.82 kworker/u32:0
7 root 20 0 0 0 0 S 0.0 0.0 0:10.72 kworker/u33:0
8 root rt 0 0 0 0 S 0.0 0.0 0:00.40 migration/0
9 root 20 0 0 0 0 S 0.0 0.0 0:00.00 rcu_bh
10 root 20 0 0 0 0 S 0.0 0.0 4:56.04 rcu_sched
11 root rt 0 0 0 0 S 0.0 0.0 0:03.77 watchdog/0
12 root rt 0 0 0 0 S 0.0 0.0 0:03.86 watchdog/1
13 root rt 0 0 0 0 S 0.0 0.0 0:00.59 migration/1
14 root 20 0 0 0 0 S 0.0 0.0 0:00.05 ksoftirqd/1
16 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 kworker/1:0H
17 root rt 0 0 0 0 S 0.0 0.0 0:03.87 watchdog/2
18 root rt 0 0 0 0 S 0.0 0.0 0:00.41 migration/2
19 root 20 0 0 0 0 S 0.0 0.0 0:00.04 ksoftirqd/2
21 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 kworker/2:0H
22 root rt 0 0 0 0 S 0.0 0.0 0:03.91 watchdog/3
23 root rt 0 0 0 0 S 0.0 0.0 0:00.41 migration/3
24 root 20 0 0 0 0 S 0.0 0.0 0:14.72 ksoftirqd/3
26 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 kworker/3:0H
27 root rt 0 0 0 0 S 0.0 0.0 0:03.87 watchdog/4
28 root rt 0 0 0 0 S 0.0 0.0 0:00.43 migration/4
29 root 20 0 0 0 0 S 0.0 0.0 0:00.16 ksoftirqd/4
3.查看消耗内存最多的前40个进程：
[root@takeout web-takeout]# ps auxw|head -1;ps auxw|sort -rn -k4|head -40 USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND root 29801 2.9 18.3 2821716 711956 ? Ssl 10:58 8:17 java -Djava.security.egd=file:/dev/./urandom -jar /app.jar systemd+ 2919 0.1 4.9 1452544 191028 ? Ssl 7月02 15:40 mysqld systemd+ 7743 1.2 2.2 343652 88800 ? SLsl 7月02 145:50 mongod --auth --storageEngine wiredTiger root 1524 0.8 1.4 1627344 54956 ? Ssl 7月02 96:06 /usr/bin/dockerd root 1534 0.2 0.4 1188184 16012 ? Ssl 7月02 25:54 docker-containerd -l unix:///var/run/docker/libcontainerd/docker-containerd.sock --metrics-interval=0 --start-timeout 2m --state-dir /var/run/docker/libcontainerd/containerd --shim docker-containerd-shim --runtime docker-runc root 607 0.0 0.3 45024 15048 ? Ss 7月02 0:08 /usr/lib/systemd/systemd-journald root 1122 0.0 0.3 562600 14716 ? Ssl 7月02 2:29 /usr/bin/python -Es /usr/sbin/tuned -l -P root 887 0.0 0.2 470312 9540 ? Ssl 7月02 0:26 /usr/sbin/NetworkManager --no-daemon root 861 0.0 0.2 220312 10996 ? Ssl 7月02 0:52 /usr/sbin/rsyslogd -n polkitd 851 0.0 0.2 536336 11584 ? Ssl 7月02 0:06 /usr/lib/polkit-1/polkitd --no-debug root 856 0.0 0.1 216988 4788 ? Ss 7月02 0:00 /usr/bin/abrt-watch-log -F BUG: WARNING: at WARNING: CPU: INFO: possible recursive locking detected ernel BUG at list_del corruption list_add corruption do_IRQ: stack overflow: ear stack overflow (cur: eneral protection fault nable to handle kernel ouble fault: RTNL: assertion failed eek! page_mapcount(page) went negative! adness at NETDEV WATCHDOG ysctl table check failed : nobody cared IRQ handler type mismatch Machine Check Exception: Machine check events logged divide error: bounds: coprocessor segment overrun: invalid TSS: segment not present: invalid opcode: alignment check: stack segment: fpu exception: simd exception: iret exception: /var/log/messages -- /usr/bin/abrt-dump-oops -xtD root 854 0.0 0.1 219484 4204 ? Ss 7月02 0:00 /usr/sbin/abrtd -d -s root 7725 0.2 0.1 347456 4076 ? Sl 7月02 33:09 docker-containerd-shim cfb7edfcbd710751322362ea32dc3025a5f28818e608ea34ce897206937b1333 /var/run/docker/libcontainerd/cfb7edfcbd710751322362ea32dc3025a5f28818e608ea34ce897206937b1333 docker-runc root 7719 0.0 0.1 911148 6888 ? Sl 7月02 1:34 /usr/bin/docker-proxy -proto tcp -host-ip 0.0.0.0 -host-port 9999 -container-ip 172.17.0.4 -container-port 27017 root 3165 0.0 0.1 414656 4056 ? Sl 7月02 0:01 docker-containerd-shim f532147cc4de43223fe2bf9641b1d84147f0f6a297c3d1792ccc5bd0070eb12e /var/run/docker/libcontainerd/f532147cc4de43223fe2bf9641b1d84147f0f6a297c3d1792ccc5bd0070eb12e docker-runc root 3076 0.0 0.1 36992 7608 ? Ssl 7月02 6:28 /usr/bin/redis-server *:6379 root 29784 0.0 0.1 412992 3996 ? Sl 10:58 0:00 docker-containerd-shim aa2d5e47a9b9a9624966fd3839128e78eec8f155931c3074439e2d61cd50a044 /var/run/docker/libcontainerd/aa2d5e47a9b9a9624966fd3839128e78eec8f155931c3074439e2d61cd50a044 docker-runc root 18707 0.0 0.1 117264 4020 pts/1 Ss 09:13 0:00 -bash root 18659 0.0 0.1 117240 4004 pts/0 Ss+ 09:12 0:00 -bash root 18656 0.0 0.1 150376 5828 ? Ss 09:12 0:00 sshd: root@pts/0,pts/1 root 1120 0.0 0.1 105996 4112 ? Ss 7月02 0:00 /usr/sbin/sshd -D root 11101 0.0 0.1 150376 5892 ? Ss 13:31 0:00 sshd: root@notty root 1 0.0 0.1 191776 4560 ? Ss 7月02 0:31 /usr/lib/systemd/systemd --switched-root --system --deserialize 21 postfix 20269 0.0 0.1 91732 4036 ? S 15:15 0:00 pickup -l -t unix -u postfix 1326 0.0 0.1 91800 4036 ? S 7月02 0:01 qmgr -l -t unix -u zabbix 31681 0.0 0.0 83944 2192 ? S 11:18 0:01 /usr/sbin/zabbix_agentd: active checks #1 [idle 1 sec] zabbix 31680 0.0 0.0 83936 2436 ? S 11:18 0:09 /usr/sbin/zabbix_agentd: listener #3 [waiting for connection] zabbix 31679 0.0 0.0 83936 2440 ? S 11:18 0:08 /usr/sbin/zabbix_agentd: listener #2 [waiting for connection] zabbix 31678 0.0 0.0 83936 2440 ? S 11:18 0:08 /usr/sbin/zabbix_agentd: listener #1 [waiting for connection] zabbix 31677 0.0 0.0 83812 2424 ? S 11:18 0:08 /usr/sbin/zabbix_agentd: collector [idle 1 sec] zabbix 31675 0.0 0.0 83812 1260 ? S 11:18 0:00 /usr/sbin/zabbix_agentd -c /etc/zabbix/zabbix_agentd.conf USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND root 99 0.0 0.0 0 0 ? S< 7月02 0:00 [bioset] root 98 0.0 0.0 0 0 ? S< 7月02 0:00 [kintegrityd] root 97 0.0 0.0 0 0 ? S< 7月02 0:00 [writeback] root 96 0.0 0.0 0 0 ? S 7月02 0:02 [khungtaskd] root 9573 0.0 0.0 0 0 ? S 7月07 0:02 [kworker/7:2] root 95 0.0 0.0 0 0 ? S< 7月02 0:00 [netns] root 94 0.0 0.0 0 0 ? S 7月02 0:00 [kdevtmpfs] root 904 0.0 0.0 110044 820 tty1 Ss+ 7月02 0:00 /sbin/agetty --noclear tty1 linux [root@takeout web-takeout]#