(LPI-1 101) System Architecture
101.1 Configure hardware settings
Sysfs and /sys
Sysfs is a virtual filesystem that the Linux kernel uses to export information about kernel objectsto processes running in user space
# mount -t sysfs sysfs /sys
Exemple :
/sys/block => block devices
Procfs and /proc
The procfs filesystem provides insight into many of the kernel data structures and even allows afew to be changed on the fly.
Sysctl
net.ipv4.conf.all.forwarding => /proc/sys/net/ipv4/conf/all/forwarding
If you have error messages or a device that does not work and you suspect interrupt conflicts,looking at /proc/interrupts
# cat /proc/interrupts
# cat /proc/dma
# cat /proc/ioports
# lsdev
# procinfo
udev and /dev
udev is responsible for the dynamic device management needed for hot plugging devices.
Files :
- /usr/lib/udev/rules.d
- /etc/udev/rules.d
# udevadm
# lspci
# cat /usr/share/hwdata/pci.ids
# lsusb
# lsusb -t
Kernel modules
# lsmod
# modinfo
# modinfo -F filename iptable_filter
/lib/modules/2.6.32-504.23.4.el6.x86_64/kernel/net/ipv4/netfilter/iptable_filter.ko
# uname -r
2.6.32-504.23.4.el6.x86_64
# ls -l /lib/modules/`uname -r`
total 3608
lrwxrwxrwx. 1 root root 51 Jun 17 2015 build -> ../../../usr/src/kernels/2.6.32-504.23.4.el6.x86_64
drwxr-xr-x. 2 root root 4096 Jun 9 2015 extra
drwxr-xr-x. 11 root root 4096 Jun 17 2015 kernel
# modprobe