Chapter 2. Monitoring and benchmark tools 61
Draft Document for Review May 4, 2007 11:35 am 4285ch02.fm
Figure 2-5 A sample /proc file system
Looking at the proc file system, we can distinguish several subdirectories that serve various
purposes, but because most of the information in the proc directory is not easily readable to
the human eye, you are encouraged to use tools such as vmstat to display the various
statistics in a more readable manner. Keep in mind that the layout and information contained
within the proc file system varies across different system architectures.
Files in the /proc directory
The various files in the root directory of proc refer to several pertinent system statics. Here
you can find information taken by Linux tools such as vmstat and cpuinfo as the source of
their output.
Numbers 1 to X
The various subdirectories represented by numbers refer to the running processes or their
respective process ID (PID). The directory structure always starts with PID 1, which refers
to the init process, and goes up to the number of PIDs running on the respective system.
Each numbered subdirectory stores statistics related to the process. One example of such
data is the virtual memory mapped by the process.
acpi
ACPI refers to the advanced configuration and power interface supported by most modern
desktop and laptop systems. Because ACPI is mainly a PC technology, it is often disabled
on server systems. For more information about ACPI refer to:
http://www.apci.info
/
proc/
1/
2546/
bus/
pci/
usb/
driver/
fs/
nfs/
ide/
irq/
net/
scsi/
self/
sys/
abi/
debug/
dev/
fs/
binvmt_misc/
mfs/
quota/
kernel/
random/
net/
802/
core/
ethernet/
