System Architecture Flashcards
modprobe
Automatically loads any dependent modules and is usually the preferred way of loading kernel modules
lsusb
- A utility for displaying the information about USB buses and associated connected devices in the system
- Reads /dev/bus/usb
/proc/interrupts
Shows the IRQs in use on the system
/proc/dma
Displays DMA addresses in use on the system
DMA address
An alternate method of communicating with I/O ports
lsmod
Lists modules currently loaded
insmod
Older method used to insert modules into the running Linux kernel
rmmod
Older method used to remove modules from the running Linux kernel
dmesg
Extracts information about the boot process
kernel
The main part of the Linux OS, responsible for the entire OS. threads, devices, filesystems and video
BIOS
Responsible for preparing the system to boot, finding the CPU, memory and disk in order to begin the boot process
/var/log/messages
Contains detailed post boot messages for your system as well as messages from applications that communicate with your kernel.
/etc/inittab
Holds run level configurations
shutdown
Used to power off the machine
shutdown -k
Send warning of impending shutdown but do not shut down
shutdown -r
Reboot after shutdown
shutdown -h
Halt or power off the system
shutdown -P
Half action to turn off power
shutdown -f
Skip fsck on next boot
shutdown -F
Force fsck on next boot
shutdown -c
Cancel a waiting shutdown
shutdown -t
Can specify the amount of time before shutting down
init
- Can be used to change run level and shutdown machine
- Last process in the boot process
Run Level 0
Used to power off the system
Run Level 1
- Single user mode
- Used for low-level system maintenance
Run Level 2
On Debian, a full multi-user mode with X running and a graphical login (undefined on all other distributions)
Run Level 3
On most distributions, a full multi-user mode with non-graphical login
Run Level 4
Usually undefined and available for customization
Run Level 5
Graphical login for most distributions
Run Level 6
Used to reboot the system
init 1
Changes to run level 1
id:2:initdefault
Says the default run level is 2
