Useful Linux Command - mkdir -p

-p (parents) option for mkdir gives you the ability to create a multiple levels deep directory with all the intermediate directories created as well.

Example: When you want to create a directory tree like this /a/b/c/d, where a,b,c,d are all not exist before, you need to create each directory independently like

mkdir /a
mkdir /a/b
mkdir /a/b/c
mkdir /a/b/c/d

if you do mkdir /a/b/c/d, you will encounter "no such file or directory" error.

With -p option, you can create /a/b/c/d with just one single line of command as shown below:

mkdir -p /a/b/c/d

Load Brocade CNA driver for Openfiler

1. Download the rpm package from Brocade website. Choose the "Linux - Other Distributions".
2. Perform the following steps to extract the bna files (Ethernet package) out from the rpm package

rpm2cpio bna_driver_linux-3.0.3.0-0.noarch.rpm > temp-file.cpio
cpio -idumv < temp-file.cpio

3. You should be able to see a usr folder in your working path. Copy all the files inside ./usr/src/bna folder to the /usr/src/.

cp ./usr/src/bna /usr/src/ -R

4. Go to /usr/src/bna and execute make.
5. After that, you should be able to locate a file call bna.ko in the /usr/src/bna directory.
6. Run insmod bna.ko to install the module and then you have your Ethernet driver loaded successfully.

Ubuntu: Running Dynamo Executable: No such file or directory

Symptom:

root@testMachine:~/iometer-2006_07_27.linux.i386-bin/src# ls
dynamo  iomtr_kstat  scripts
root@testMachine:~/iometer-2006_07_27.linux.i386-bin/src# ./dynamo
-bash: ./dynamo: No such file or directory

For this case, you need to make sure you have ia32-libs installed. To check whether the package is installed, run:

root@testMachine:/# dpkg -l ia32-libs
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name           Version        Description
+++-==============-==============-============================================
ii  ia32-libs      20090808ubuntu ia32 shared libraries for use on amd64 and i

if it shows "un", meaning ia32-libs is not installed. If is installed, it will show "ii".

Install ia32-libs by

apt-get install ia32-libs

* Please note that, for simplicity, i using root account to run the above command, you might need to add sudo in front of the above commands if you are not using root account.

dpkg : status database area is locked by another process while trying to install

This will happen if you accidentally kill the apt-get process and dpkg become orphan process. To solve this problem you can either

Reboot your server or do the following:

sudo rm /var/lib/dpkg/lock

sudo dpkg --configure -a

How to change boot order for Ubuntu (>9.10)

1. cat /boot/grub/grub.cfg
see the order of the wanted kernel. Starts from 0.

Example:

...
### BEGIN /etc/grub.d/10_linux ###
menuentry 'Ubuntu, with Linux 2.6.35-30-server' --class ubuntu --class gnu-linux
# this is 0
--class gnu --class os {
recordfail
insmod part_msdos
insmod ext2
set root='(hd0,msdos1)'
search --no-floppy --fs-uuid --set 71119ab7-e93f-49a9-80f1-efc11398c954
linux /boot/vmlinuz-2.6.35-30-server root=UUID=71119ab7-e93f-49a9-80f1
-efc11398c954 ro quiet
initrd /boot/initrd.img-2.6.35-30-server
}

# this is 1
menuentry 'Ubuntu, with Linux 2.6.35-30-server (recovery mode)' --class ubuntu -
-class gnu-linux --class gnu --class os {
recordfail
insmod part_msdos
insmod ext2
set root='(hd0,msdos1)'
search --no-floppy --fs-uuid --set 71119ab7-e93f-49a9-80f1-efc11398c954
echo 'Loading Linux 2.6.35-30-server ...'
linux /boot/vmlinuz-2.6.35-30-server root=UUID=71119ab7-e93f-49a9-80f1
-efc11398c954 ro single
echo 'Loading initial ramdisk ...'
initrd /boot/initrd.img-2.6.35-30-server
}

# this is 2
menuentry 'Ubuntu, with Linux 2.6.32-28-server' --class ubuntu --class gnu-linux
--class gnu --class os {
recordfail
insmod part_msdos
insmod ext2
set root='(hd0,msdos1)'
search --no-floppy --fs-uuid --set 71119ab7-e93f-49a9-80f1-efc11398c954
linux /boot/vmlinuz-2.6.32-28-server root=UUID=71119ab7-e93f-49a9-80f1
-efc11398c954 ro quiet
initrd /boot/initrd.img-2.6.32-28-server
}

# this is 3
menuentry 'Ubuntu, with Linux 2.6.32-28-server (recovery mode)' --class ubuntu -
-class gnu-linux --class gnu --class os {
recordfail
insmod part_msdos
insmod ext2
set root='(hd0,msdos1)'
search --no-floppy --fs-uuid --set 71119ab7-e93f-49a9-80f1-efc11398c954
echo 'Loading Linux 2.6.32-28-server ...'
linux /boot/vmlinuz-2.6.32-28-server root=UUID=71119ab7-e93f-49a9-80f1
-efc11398c954 ro single
echo 'Loading initial ramdisk ...'
initrd /boot/initrd.img-2.6.32-28-server
}
### END /etc/grub.d/10_linux ###
...

2. vi /etc/default/grub
change GRUB_DEFAULT=0 value to wanted kernel

Example:

If we want to boot to 'Ubuntu, with Linux 2.6.32-28-server' we should set 2

3. run update-grub to update

4. reboot and check with uname -r to see if correct kernel selected.

Iphone data and charging cable

Daiso is selling it for SGD 2 and it works! :)

Bluetooth disappear after reformat Dell Inspiron 1525

If you are not able to turn on your bluetooth after reformat and reinstall your inspiron 1525 laptop. You might want to try the following patch from Dell

Dell Bluetooth Patch

Or do a google search on the following keywords

BTW Radio ON, A00