vim /etc/apt/sources.list


Debian for v6(Squeeze) to v7(Wheezy)

deb http://ftp.debian.org/debian/ wheezy main
deb-src http://ftp.debian.org/debian/ wheezy main

deb http://security.debian.org/ wheezy/updates main
deb-src http://security.debian.org/ wheezy/updates main

# wheezy-updates, previously known as 'volatile'
deb http://ftp.debian.org/debian/ wheezy-updates main
deb-src http://ftp.debian.org/debian/ wheezy-updates main

*https://www.cyberciti.biz/faq/howto-debian-linux-upgrade-6-squeeze-to-7-wheezy/
.
Debian for v7(Wheezy) to v8(Jessie)

deb http://ftp.debian.org/debian/ jessie main
deb-src http://ftp.debian.org/debian/ jessie main

deb http://security.debian.org/ jessie/updates main contrib
deb-src http://security.debian.org/ jessie/updates main contrib

# wheezy-updates, previously known as 'volatile'
deb http://ftp.debian.org/debian/ jessie-updates main contrib
deb-src http://ftp.debian.org/debian/ jessie-updates main contrib

*http://www.muktware.io/upgrade-from-debian-7-to-debian-8/
.
upgrade debian

apt-get update
apt-get upgrade -y
apt-get dist-upgrade -y

#if error “There is no public key available for the following key IDs”
#fix by http://taxze.com/?p=19

reboot

.

#after reboot
cat /etc/debian_release
lsb_release -a
uname -a

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