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Package Management Tools

Upgrading with dselect

Once you have installed a system and have all the necessary packages installed,

maintaining such a system with dselect is relatively easy. dselect (actually

dpkg) keeps a database detailing the state of the system. What packages are

installed, their versions, and additional necessary information are contained

in the directory /var/lib/dpkg/info while the status of installed packages are

kept in /var/lib/dpkg/status. The file /var/lib/dpkg/available is updated by

dselect whenever a new archive is to be installed. This is not automatic, but

happens when the [U]pdate item is chosen from the main dselect menu.

From the information in these areas, dselect can do an upgrade with little

interaction. There are several preparatory tasks that should be done first,

to insure dselect's success. There were several incremental upgrades to dpkg

during the life of the 1.2 distribution. At one point upgrading may have

 broken  the available file. The transition to actually using a new feature did

not go as smoothly as expected. To get past this problem it will be necessary

that the available file get removed. This is done by the command:

dpkg   clear avail

After executing this command it will be possible to install the following pack 

ages using dpkg:

  The new version of ld.so

  The new version of libc5

  The new version of dpkg

These are critical packages and, although dselect can often  do the right thing 

when upgrading an installed system, it is advisable to install these by hand.

In any case it is often necessary to upgrade dpkg by hand. This package has