Chapter 8. Keeping your Debian system up to date

47

Then run

apt get update

followed by

apt get dist upgrade

Answer any questions that might come up, and your system will be upgraded.

To use APT with

dselect

, choose the APT access method in dselect's method selection screen

(option 0) and then specify the sources that should be use. The configuration file is

/etc/apt

/sources.list

, and its format is described in the

sources.list(5)

manual page.

If you want to use CDs to install packages, you can use

apt cdrom

. For details, please see the

Release Notes, section  Setting up for an upgrade from a local mirror .

Please note that when you get and install the packages, you'll still have them kept in your /var

directory hierarchy. To keep your partition from overflowing, remember to delete extra files

using

apt get clean

and

apt get autoclean

, or to move them someplace else (hint:

use

apt move

).

8.2.2 dpkg ftp

This is an older access method for

dselect

. It can be invoked from within

dselect

, thereby

allowing a user the ability to download files and install them directly in one step. To do this,

select the

ftp

access method in

dselect

(option 0) and specify the remote host name and

directory.

dpkg ftp

will then automatically download the files that are selected (either in this

session of

dselect

or earlier ones).

Note that, unlike the

mirror

program,

dpkg ftp

does not grab everything at a mirror

site. Rather, it downloads only those files which you have selected (when first starting up

dpkg ftp

), and which need to be updated.

dpkg ftp

is somewhat obsolete. You should use the APT access method with ftp:// URLs in

sources.list

instead.

8.2.3 mirror

This Perl script, and its (optional) manager program called

mirror master

, can be used to

fetch user specified parts of a directory tree from a specified host via anonymous FTP.

mirror

is particularly useful for downloading large volumes of software. After the first time

files have been downloaded from a site, a file called

.mirrorinfo

is stored on the local host.

Changes to the remote file system are tracked automatically by

mirror

, which compares this

file to a similar file on the remote system and downloads only changed files.