Para garantir que o sistema tenha as versões de software e correcções de segurança mais recentes, as actualizações devem ser feitas com regularidade. A actualização do software é feita em duas partes: a actualização lista de software disponível nos repositórios e a instalação das eventuais evoluções. Ambas as operações são feitas utilizando o comando aptitude, com diferentes opções.

A actualização da lista de software disponível nos repositórios é muito simples:

root@server:~# aptitude update
Get:1 http://ftp.pt.debian.org squeeze Release.gpg [835 B]
Ign http://ftp.pt.debian.org/debian/ squeeze/main Translation-en
Ign http://ftp.pt.debian.org/debian/ squeeze/main Translation-en_US
Get:2 http://ftp.pt.debian.org squeeze Release [89.9 kB]
Get:3 http://security.debian.org squeeze/updates Release.gpg [835 B]
Get:4 http://ftp.pt.debian.org squeeze/main amd64 Packages/DiffIndex [2,038 B]
Ign http://security.debian.org/ squeeze/updates/main Translation-en
Ign http://security.debian.org/ squeeze/updates/main Translation-en_US
Get:5 http://security.debian.org squeeze/updates Release [44.6 kB]
Get:6 http://ftp.pt.debian.org squeeze/main amd64 2010-10-22-0256.49.pdiff [10.1 kB]
Get:7 http://ftp.pt.debian.org squeeze/main amd64 2010-10-22-0256.49.pdiff [10.1 kB]
Get:8 http://ftp.pt.debian.org squeeze/main amd64 2010-10-22-0256.49.pdiff [10.1 kB]
Get:9 http://security.debian.org squeeze/updates/main amd64 Packages [56.3 kB]
Get:10 http://ftp.pt.debian.org squeeze/main amd64 2010-10-22-1524.42.pdiff [8,117 B]
Get:11 http://ftp.pt.debian.org squeeze/main amd64 2010-10-22-1524.42.pdiff [8,117 B]
Get:12 http://ftp.pt.debian.org squeeze/main amd64 2010-10-22-1524.42.pdiff [8,117 B]
Fetched 215 kB in 3s (71.0 kB/s)

Current status: 5 updates [+5].

Existem actualmente 5 actualizações disponíveis para o software instalado.

A instalação das actualizações é igualmente simples:

root@server:~# aptitude safe-upgrade
The following packages will be upgraded:
  libc-bin libc6 locales tasksel tasksel-data
5 packages upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 9,776 kB of archives. After unpacking 176 kB will be freed.
Do you want to continue? [Y/n/?] y
Get:1 http://ftp.pt.debian.org/debian/ squeeze/main tasksel-data all 2.84 [105 kB]
Get:2 http://ftp.pt.debian.org/debian/ squeeze/main tasksel all 2.84 [87.2 kB]
Get:3 http://security.debian.org/ squeeze/updates/main libc-bin amd64 2.11.2-6+squeeze1 [745 kB]
Get:4 http://security.debian.org/ squeeze/updates/main libc6 amd64 2.11.2-6+squeeze1 [4,143 kB]
Get:5 http://security.debian.org/ squeeze/updates/main locales all 2.11.2-6+squeeze1 [4,697 kB]
Fetched 9,776 kB in 20s (480 kB/s)
Preconfiguring packages ...
(Reading database ... 16181 files and directories currently installed.)
Preparing to replace libc-bin 2.11.2-6 (using .../libc-bin_2.11.2-6+squeeze1_amd64.deb) ...
Unpacking replacement libc-bin ...
Processing triggers for man-db ...
Setting up libc-bin (2.11.2-6+squeeze1) ...
(Reading database ... 16181 files and directories currently installed.)
Preparing to replace libc6 2.11.2-6 (using .../libc6_2.11.2-6+squeeze1_amd64.deb) ...
Unpacking replacement libc6 ...
Setting up libc6 (2.11.2-6+squeeze1) ...
(Reading database ... 16181 files and directories currently installed.)
Preparing to replace tasksel-data 2.82 (using .../tasksel-data_2.84_all.deb) ...
Unpacking replacement tasksel-data ...
Preparing to replace tasksel 2.82 (using .../archives/tasksel_2.84_all.deb) ...
Unpacking replacement tasksel ...
Preparing to replace locales 2.11.2-6 (using .../locales_2.11.2-6+squeeze1_all.deb) ...
Unpacking replacement locales ...
Processing triggers for man-db ...
Setting up locales (2.11.2-6+squeeze1) ...
Generating locales (this might take a while)...
  en_US.UTF-8... done
Generation complete.
Setting up tasksel-data (2.84) ...
Setting up tasksel (2.84) ...

Current status: 0 updates [-5].

Foram aplicadas 5 actualizações, estando agora o sistema actualizado.

• Referência Debian, 2.2. Operações básicas de gestão de pacotes (http://www.debian.org/doc/manuals/reference/ch02.pt.html#_basic_package_management_operations)