10.6 Monitoring IO Performance
Iostat-x View disk Usage There is a very important indicator%util, the larger the value, the more the hard disk is occupied
Iotop commands need to be installed
Iotop is also a dynamic display, focusing on the IO column
10.7 Free Command
free-m/-g/-h Command usage
The difference between buffer and Cacher
Disk-to-memory (cache)-->CPU
Cpu--> memory (buffer)--disk
10.8 PS Command
PS aux | Use to view a process
To see where the process started from, you need to know the PID number, for example, the PID is 505
Type of Process stat
10.9 Viewing network status
viewing ports for listening
View only the TCP or UDP protocol
Netstat-an Dynamic state, check the TCP IP 3 handshake 4 times the process of waving
View the sum of each state
Netstat-an | awk '/^tcp/{++sta[$NF]} END {for (key in STA) print key, "\ T", Sta[key]}
Ss-an does not show the name of the process, Netstat-an is possible
View the Listen process
10.10 Linux under Grab Bag
Tcpdump is not installed by default
Tcpdump-nn-i Ens33 The first n shows the IP, the second n is the display port number, if the host name is not added n
Do not add nn
Tcpdump-nn-c 10-w 1.cap only catch 10 packets and save to 1.cap file, 1.cap is not cat's
If you want to view 1.cap to use the command
Tcpdump-r/tmp/1.cap
Tshark needs to be installed
Remember this command, check the network card capture specific information, you can clearly see what time there is what IP visited the site, access to the site of what links
Tshark-n-T a-r http.request-t fields-e "Frame.time"-E "ip.src"-E "http.host"-E "Http.request.method"-E "http.requ Est.uri "
Extended TCP three-time handshake four times wave http://www.doc88.com/p-9913773324388.html
Tshark several usages: http://www.aminglinux.com/bbs/thread-995-1-1.html
10.6 Monitoring IO Performance 10.7free Command 10.8ps command 10.9 View network status 10.10linux grab bag
