cp -p : Use if you do not want to change mod times and permissions

linux kernel memory leak

Changing xterm title

cscope

find . -name "*.[chsS]" -follow -print > cscope.files
cscope -bq
cscope -d

-b: build
-q: cross references

Ctrl-b will browse through history of cscope searches that u performed earlier.

Touchpad tapping in Suse 9.1

TRY
//Putting it at the end of the append
boot=/dev/hda
default="linux"
prompt
nowarn
timeout=100
message=/boot/message
menu-scheme=wb:bw:wb:bw
image=/boot/vmlinuz
label="linux"
root=/dev/hda5
initrd=/boot/initrd.img
append="devfs=mount acpi=ht resume=/dev/hda6 splash=silent psmouse.proto=imps"
vga=788
read-only

wireless lan setup in SuSE 9.1

Suse 9.1 recognizes the wireless cards: Orinoco and Belkin
and loads the drivers automatically. But the following have to be done in order to successfully configure them:

1. LOG IN AS ROOT
2. set essid
3. set key
4. set default gateway if u know its IP address
5. set it as pcmcia
6. set default route: destination=default, mask=0.0.0.0, gateway=192.168.2.1, interface=eth1
7. set it to be configured at boot time.

after spending 3 and 1/2 hours on this stupid thing, lesson learnt:

LOG IN AS ROOT AND DO EVERYTHING!!!

dunno why it cannot configure these cards properly when we su from another user's login.

kernel syncronization

You can use the macros DECLARE_MUTEX and DECLARE_MUTEX_LOCKED

to declare semaphores with initial values of 1 or 0. You can

then use the up and down functions on theese variables.



static DECLARE_MUTEX(mymutex);

void myfunc()

{

   down(mymutex);

   ...

   up(mymutex);

}

ATI Radeon IGP 340M driver for linux installation

 

linux page cache

VFS in linux kernel 2.4

Disk cloning using dd

This is a step by step solution for the people who want to get straight to the point.
You can print only this page and use it as a quick reference.

Local Step 1:
root@from# dd if=/dev/hda of=/safe/place/hda.mbr.dd bs=1 count=512
root@from# sfdisk –d /dev/hda > /safe/place/hda.pt.sfdisk
root@from# dd if=/dev/hda1 of=/safe/place/hda1.dd bs=512
root@from# dd if=/dev/hda2 of=/safe/place/hda2.dd bs=512
root@from# dd if=/dev/hda3 of=/safe/place/hda3.dd bs=512
root@from# dd if=/dev/hda5 of=/safe/place/hda5.dd bs=512
root@from# dd if=/dev/hda6 of=/safe/place/hda6.dd bs=512

Local Step 2:
root@to# dd if=/safe/place/hda.mbr.dd of=/dev/hdc bs=1
root@to# sfdisk –R /dev/hdc
root@to# sfdisk –n /dev/hdc < /safe/place/hda.pt.sfdisk
root@to# sfdisk /dev/hdc < /safe/place/hda.pt.sfdisk
root@to# dd if=/safe/place/hda1 of=/dev/hdc1 bs=512
root@to# dd if=/safe/place/hda2 of=/dev/hdc2 bs=512
root@to# dd if=/safe/place/hda3 of=/dev/hdc3 bs=512
root@to# dd if=/safe/place/hda5 of=/dev/hdc5 bs=512
root@to# dd if=/safe/place/hda6 of=/dev/hdc6 bs=512

Remote Step 1 (clone the mbr)
root@to# nc –v –l –p 2000 | gzip –cd > /dev/hda
root@from# dd if=/dev/hda bs=512 count=1 | gzip –c9 | nc –q 2 2000
root@to# nc –v –l –p 2000 | gzip –cd > hda.sfdisk
root@from# sfdisk –d /dev/hda | gzip –c9 | nc –q 2 2000
root@to# sfdisk –n /dev/hda < hda.sfdisk
Test OK…
root@to# sfdisk /dev/hda < hda.sfdisk
root@to# sfdisk –R /dev/hda

5.4 Remote Step 2 (clone the partitions):
root@to# nc –v –l –p 2000 | gzip –cd | dd of=/dev/hdaX
root@from# dd if=/dev/hdaX | gzip –c9 | nc –q 2 2000
Repeat this step for the number of partitions that you have. All that will vary is the
partition X eg. hda2, hda3, hda4 etc.