2018-04-20 "Bird Brother's Linux private cuisine Basic Study (Fourth Edition)" chapter 16th process Management notes

Content:
Program binaries binary file entity
Process PID A program that is in operation
Daemon Service Residency Procedures
Parent PID (PPID)
The Network service is responsible for the port Bu4 Port (port) that is monitored by the Internet to provide external client connection requirements.
Job Control work Management

Command:
CTRL+FN+ALT+F1: Display Graphical interface
Ctrl+fn+alt+f2~f6: Text terminal
CTRL+FN+ALT+F7: Shining Underline
& throw work into the background its execution
CTRL + Z: Paused and dropped into the background
CTRL + C: Interrupt Current Program
Ctrl+d: Keyboard input End
Jobs-lrs Viewing an interrupted program
FG%jobnumber foreground abbreviation that puts the interrupt program in the background back into the foreground to execute
BG%jobnumber Let work in the context of the state operation
Nohup to System Run command instead of current terminal
PS intercepts the current operation of this user process
Ps-l-L lists the PID information in detail
PS aux lists the processes that are currently in memory. The data displayed is not the same as the previous command
Top dynamic observation process changes
Pstree Tree Display process dependencies
Kill-signal%jobnumber Signal 1, 2, 9, (SIGTERM)
KILL-L listing all executable information
Killall
Nice
Renice
Free observation of memory usage
Uname Inquiry System and core information
Uptime Observing System start-up time and workload
Netstat tracking network or slot files
DMESG analysis of core-generated messages at boot time

Vmstat Detection System Resource change
The data displayed:
? process field (procs):
R: Waiting for the number of processes in operation;
B: The number of processes that cannot be awakened.
The more these two projects, the busier the system is (because the system is too busy, so many processes cannot be executed or are waiting to be woken up).
? memory field:
SWPD: The capacity of virtual memory to be used;
Free: Memory capacity that is not being used;
Buff: for buffer memory;
Cache: for cache. This part is the same as free.
? Memory replacement space (Swap):
Si: The amount of the process taken out of the disk;
So: the capacity of the swap to be written to the disk because of insufficient memory.
If the value of the si/so is too large, it means that the data in memory is often transmitted between the disk and the main memory, the system performance will be poor!
? disk read/write (IO):
BI: The number of chunks read into by disk;
Bo: The number of chunks written to disk.
If the value of this part is higher, the I/O on behalf of the system is very busy!
? System:
In: Number of processes interrupted per second;
CS: The number of event switches per second;
The larger the two values, the more frequent the communication between the system and the interface device! These interface devices, of course, include disks, network cards, time clocks, and so on.
? Cpu:
US: CPU usage status of non-core layer;
SY: The CPU state used by the core layer;
ID: idle state;
WA: CPU state required to wait for I/O;
ST: the CPU usage state that was stolen by virtual machine (2.6.11 is supported later).

Fuser a file (or file system) to find the program that is using the file
Lsof lists the file names opened by the process
Pidof to find the PID of an executing process
Fuser a file (or file system) to identify the process that is using the file
Lsof lists the file names that are opened by the process
Pidof find out the PID of an executing program
Getenforce [0|1] view, toggle SELinux mode
Sestatus View SELinux Policy
GETSEBOOL-A Rule Name
Seinfo to list SELinux information
Sesearch
Setsebool to modify the Boolean value of the SELinux rule Setsebool

2018-04-20 "bird Brother's Linux private dishes Basic Study (Fourth Edition)" chapter 16th process Management notes