91d437f0fb56cfb5b64de81b60bd6738

• rm -fr ~/.local/share/recently-used.xbel
• touch ~/.local/share/recently-used.xbel
• chmod ugo-wr ~/.local/share/recently-used.xbel
• sudo chattr +i ~/.local/share/recently-used.xbel

Option 2

• rm -fr ~/.local/share/recently-used.xbel
• mkdir ~/.local/share/recently-used.xbel

I use China Unicom 3G on my Android phone in China. To get rid of #GFW in China, with Richard guidance, I set up L2TP/IPSec VPN on Ubuntu, hosted @ http://Linode.com. Simply document the steps.

IPSec

sudo apt-get install openswan

Use Pre- Shared Key. Change /etc/ipsec.conf

version 2.0
 config setup
     nat_traversal=yes
     virtual_private=%v4:10.0.0.0/8,%v4:192.168.0.0/16,%v4:172.16.0.0/12
     oe=off
     protostack=netkey

conn L2TP-PSK-NAT
     rightsubnet=vhost:%priv
     also=L2TP-PSK-noNAT

conn L2TP-PSK-noNAT
     authby=secret
     pfs=no
     auto=add
     keyingtries=3
     rekey=no
     ikelifetime=8h
     keylife=1h
     type=transport
     left=YOUR.SERVER.IP.ADDRESS
     leftprotoport=17/1701
     right=%any
     rightprotoport=17/%any

and change /etc/ipsec.secrets to

YOUR.SERVER.IP.ADDRESS %any: PSK "YourSharedSecret"

Apply the following change

for each in /proc/sys/net/ipv4/conf/*
 do
     echo 0 > $each/accept_redirects
     echo 0 > $each/send_redirects
 done

Verify IPSec configuration, then restart the daemon

sudo ipsec verify

sudo /etc/init.d/ipsec restart

L2TP

Install xl2tpd

sudo apt-get install xl2tpd

Change /etc/xl2tpd/xl2tpd.conf

[global]
 ipsec saref = yes

[lns default]
 ip range = 10.1.2.2-10.1.2.255
 local ip = 10.1.2.1
 refuse chap = yes
 refuse pap = yes
 require authentication = yes
 ppp debug = yes
 pppoptfile = /etc/ppp/options.xl2tpd
 length bit = yes

PPP

sudo apt-get install ppp

Change /etc/ppp/options.xl2tpd

require-mschap-v2
 ms-dns 8.8.8.8
 ms-dns 8.8.4.4
 asyncmap 0
 auth
 crtscts
 lock
 hide-password
 modem
 debug
 name l2tpd
 proxyarp
 lcp-echo-interval 30
 lcp-echo-failure 4

Add a test user in /etc/ppp/chap-secrets

# user      server      password            ip
 test        l2tpd       testpassword        *

Restart xl2tpd

sudo /etc/init.d/xl2tpd restart

Apply iptables firewall rules

iptables --table nat --append POSTROUTING --jump MASQUERADE

echo 1 > /proc/sys/net/ipv4/ip_forward

Automate ipsec and xl2tpd daemons when system boots

chkconfig ipsec on

chkconfig xl2tpd on

And add the following into /etc/rc.local

iptables --table nat --append POSTROUTING --jump MASQUERADE
for each in /proc/sys/net/ipv4/conf/*
do
echo 0 > $each/accept_redirects
echo 0 > $each/send_redirects
done
/etc/init.d/ipsec restart

1. sudo add-apt-repository ppa:gnome3-team/gnome3
2. sudo apt-get update
3. sudo apt-get dist-upgrade
4. sudo apt-get install gnome-shell

Uninstall repository

1. sudo apt-get install ppa-purge
2. sudo ppa-purge ppa:gnome3-team/gnome3

Struggled unstable Gnome3 on Ubuntu Natty for a while, then decided to try Fedora 15 which has default Gnome3. Now I need to create a Fedora 15 bootable USB on Ubuntu Natty. Here are steps:

1. Download Fedora 15 ISO certainly
2. Double click the ISO file, then copy the file LiveOS/livecd-iso-to-disk from the ISO to wherever you want
3. sudo apt-get install syslinux (if you don’t have it)
4. Format the USB, eg /dev/sdc1
5. sudo ./livecd-iso-to-disk –overlay-size-mb 512 /path/Fedora-15-i686-Live-Desktop.iso /dev/sdc1

WCDMA 3G Wireless: Huawei e1750

Service Provider: China Unicom

• Install USB driver then reboot
  sudo apt-get install usb-modeswitch
• Go to nm-conntion-editor > Mobile Broadband > Add … >

• Configure
  APN: uninet
  PIN: 1234

One of my colleagues was impressed by the 3D desktop, driven by CompizConfig on my Ubuntu 10.04.

He then asked me how to install one on his ThinkPad T43 machine. Giving the steps:

1. Find a 2G USB key. Click Download @ http://www.ubuntu.com/desktop
2. You’d be given an ISO file. Then follow the step 2 & select “Create a USB stick” @ http://www.ubuntu.com/desktop/get-ubuntu/download
   
3. Restart your Windows then boot from USB key
4. From the same page you can either run Ubuntu from USB to start the installation