Study Notes

Modify the kernel to make Linux run faster:

# cd /usr/src/linux-2.4 
# make mrproper 
# make menuconfig

This step will display a dialog,and I exclude some items which will never be used, for example, Fiber channel,isdr,and pcmcia,(Type “N”),and then save the new configuration,issue the following command:

# make dep (it will take about 5 minutes) 
# make clean (5 seconds) 
# make bzImage (10 minutes) 
# make modules (it's long and will take about 30 minutes) 
# make modules_install

Note: it is “modules_install” which have no backspace between “modules” and “_install”. and if issue the “make modules -install”, the process will failed with error. The final step is issueing the “reboot”. I’ve tried all the above steps, and my Linux runs faster after rebooting.

nroff: emulate nroff command with groff.

# nroff -man man/libnet.3 | less

Issue the commands as other user account:

# su - username -c "ls"

For example, let root issues “ls” :

# su - root -c "ls"

Uncompress the “.bz” file:

# tar -jvxf xxx.bz

If the file “/etc/inittab” was modified, issue the following command to make the configuration activity.

# init q

Q or q, tell init to re-examine the /etc/inittab fill.
S or s, tell init to switch to single user mode.

Issue some continuous commands, and it will break as soon as error happens.

# command1 && command2 && command3 

Uncompress the file included in rpm:

# cat xxx.rpm | rpm2cpio | pax -r

How to mount harddisk and directory owned by local Windows system or Remote windows system?

# mount -t smbfs -o username=x, password=x, //share_path /mnt/c 

Ethereal — capture packets.

Create and use .iso file:

# mkisofs -J -r -o xxx.iso /test 
# mount -o loop xxx.iso /mnt/cdrom 

Uncompress xxx.bz file:

# tar -I xxx.bz or # bunzip2 xxx.bz

Check the file’s rpm name:

# rpm -qf /usr/bin/ls

List description information:

# rpm - qpi

List file information:

# rpm - qpl

Configure the Memory limitation in Grub:

grub> kernel /boot/vmlinuz-2.4.19 20 boot=/dev/hda2 mem=120MB 

Type Chinese output:

# ls --show-control-chars

Make a Linux boot disk:

# mkbootdisk --device /dev/fd0 2.4.20 

Where 2.4.20 is directory in /lib/modules

Modify the ethernet device’s MAC address:

# ifconfig eth0 down 
# ifconfig eth0 hw ether 00:AA:BB:CC:DD 
# ifconfig eth0 up 

A very important command which is used to check ethernet card’s statue:

# mii-tool -v 

mii-tool -view, manipulate media-independent interface status.This utility checks or sets the status of a network interface Media Independent Interface(MII) .
-w watch monitor for link status changes

# du ./ --max-depth=1 
# du -sm /directory

List the existed users account in the Linux:

# cat -fl -d: /etc/passwd 

Find the MAC address of local ethernet card:

# arp 
# /sbin/arp