Linux performance monitoring and network commands

Recent need to collate commands for device performance monitoring (Linux)

1. Uptime

Eg:22:59:10 up, 23:05, 3 users, load average:0.29, 0.43, 0.94

One minute, five minutes, 15 minute load respectively

Represents the average number of processes waiting in the CPU wait queue per unit time

2. free [-B | -k| -m] Specifies the output unit

eg

Total used free shared buffers Cached

mem:8041612 3954464 4087148 644068 382832 1644220

-/+ buffers/cache:1927412 6114200

swap:10740732 157868 10582864

Total = used + Free

(-buffers/cache) Used memory: (refers to the first part of the Mem line in the used–buffers–cached)
(+buffers/cache) Free Memory: (refers to the first part of the Mem line of Free + buffers + cached)

3. DF [-H|-I|-T]-t display file system type

Df-ht

/dev/sda6 ext4 184G 67G 108G 39%/

None Tmpfs 4.0K 0 4.0K 0%/sys/fs/cgroup

Udev Devtmpfs 3.9G 4.0K 3.9G 1%/dev

Tmpfs tmpfs 786M 1.6M 784M 1%/run

None Tmpfs 5.0M 0 5.0M 0%/run/lock

None Tmpfs 3.9G 250M 3.6G 7%/RUN/SHM

None Tmpfs 100M 40K 100M 1%/run/user

Monitoring network:

Netstat

Options:

-S displays various protocol data statistics

-N Use digital form of IP, port number, user ID instead of host, protocol, user and other name information

-P Displays the process name and the corresponding process ID number

-L displays only the socket interface information being monitored

-U View UDP connection Information

-T View TCP

Netstat-lnp
TCP 0 0 127.0.1.1:53 0.0.0.0:* LISTEN

Top [-d|-p] Refresh interval view PID process information

Input m can be used according to memory usage, n can select output color according to process number, Z

Top-d 1-p

Route View routing Information

Route Add destination network GW gateway address

Route del Target Network

Route add default GW 192.168.1.1 Add the specified gateway as the Defaults gateway

Route add-net 172.16.9.0/24 GW 192.168.0.12 add gateway for specified network

Route add-net 192.168.18.0 netmask 255.255.255.0 dev eth0 Add routing records that specify data to be transferred to the Eth0 network segment via the 192.168.18.0 NIC

Route del default GW 192.168.18.1 Delete the Defaults gateway

Route Del-net 192.168.18.0/24 Delete a gateway record for a specified network segment

Traceroute-i using ICMP encapsulation

Traceroute-i www.google.com

Nslookup www.google.com

Server:127.0.1.1

Address:127.0.1.1#53

Non-authoritative Answer:

Name:www.google.com

address:78.16.49.15

Dig www.baidu.com

modifying kernel parameters

1. Turn on route forwarding

   echo "1" >/proc/sys/net/ipv4/ip_forward

2. Disable ICMP packets (ping-forbidden)

   echo "1" >/proc/sys/net/ipv4/icmp_echo_ignore_all

3. Adjustment process can open the total amount of files

   echo "108248" >/proc/sys/fs/file-max

This article is from the Linux Learning Notes blog, so be sure to keep this source http://rockycai.blog.51cto.com/8871643/1879449

Linux performance monitoring and network commands