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lscpu
 lsblk = show our system block information
-t = show tree
-f = show the filesystem,uuid,type ,where is it mount
-i = show in ASCII character

lspci = list all pci ID and information
show port and slot
-v = verbose
-m = space limited,can be parsed
-vmm = show verbose and can be parse(easy to read)
-t = listing in tree can be combined with -v

lsscsi = show scsi information
-d
-g =
-s = show size
-v = verbose
-l = level of running


lsusb =how usb information

-v = verbose
-s =show specific bus and dev number
-d = use device number to specific 
-t = show in tree format

lsraid = show raid information

lsdev = show infromation of all devices connected to our system




ALL OF THE INFORMATIONO ARE TAKEN FROM /DEV AND /PROC THAT ARE TIED TOGETHER


What is sysvinit
=package that contain group of processes that control basic system function of the system

=include 'init' app ,which boot very first in after kernet started

=control startup.runnin and shutdown of other program.

init always PID 1

Boot Process
-->Turn on --> BIOS/EFI-->scan and pass to primary boot sector(can be choosed) -->MBR(first 512 bytes) can be ,anything-->boot loader executed, GRUB,GRUB2,LILO-->boot loader boot kernel --> kernel boot initrd /module -->root fs is mounted --> init load (/sbin/init) -->/etc/inittab is read and script is run --> module inside init is loaded -->check root fs -->network dev started --> remote fs mounted -->init rescans /etc/inittab and set the sytem to default runlevel and complete the execution in numeric order--> tty is loaded -->then system login prompt displaayed.


init will set runlevel

RUNLEVEL
0 - halt (SHUTDOWN)
1 - single user 
2 - multi-user(no remote /fs)
3 Full Multi-User (remote fs)
4 - Unused
5 -X11 with GDE
6 - Reboot

Boot the system(sysV and RC scripts - sysvinit)

telinit
init