Karena Debian memiliki beberapa waktu untuk evolusi antara rilis stable, Anda harus membaca catatan rilis sebelum melakukan upgrade.

In this section, we will focus on upgrading a Buster system to Bullseye. This is a major operation on a system; as such, it is never 100% risk-free, and should not be attempted before all important data has been backed up.

Another good habit which makes the upgrade easier (and shorter) is to tidy your installed packages and keep only the ones that are really needed. Helpful tools to do that include aptitude, deborphan, debfoster, and apt-show-versions (see Bagian 6.2.7, “Pelacakan Otomatis Paket Terinstall”). For example, you can use the following command, and then use aptitude's interactive mode to double check and fine-tune the scheduled removals:

# deborphan | xargs aptitude --schedule-only remove

Now for the upgrading itself. First, you need to change the /etc/apt/sources.list file to tell APT to get its packages from Bullseye instead of Buster. If the file only contains references to Stable rather than explicit codenames, the change isn't even required, since Stable always refers to the latest released version of Debian. In both cases, the database of available packages must be refreshed with the apt update command or the refresh button in synaptic (Bagian 6.2.1, “Inisialisasi”).

Once these new package sources are registered, you should first do a minimal upgrade with apt upgrade et al. as described in Bagian 6.2.3, “Pembaharuan Sistem”. By doing the upgrade in two steps, we ease the job of the package management tools and often ensure that we have the latest versions of those, which might have accumulated bugfixes and improvements required to complete the full distribution upgrade.

Once this first upgrade is done, it is time to handle the upgrade itself, either with apt full-upgrade, aptitude, or synaptic (Bagian 6.7, “Upgrade dari Satu Distribusi Stable ke Berikutnya”). You should carefully check the suggested actions before applying them: you might want to add suggested packages or deselect packages which are only recommended and known not to be useful. In any case, the frontend should come up with a scenario ending in a coherent and up-to-date Bullseye system. Then, all you need is to do is wait while the required packages are downloaded, answer the debconf questions and possibly those about locally modified configuration files, and sit back while APT does its magic.

Dalam kegemasan usaha terbaik maintainer Debian, upgrade sistem utama tidak selalu selancar yang Anda inginkan. Versi terbaru perangkat lunak mungkin tidak cocok dengan versi sebelumnya (misalnya, perilaku bawaannya atau format data mereka mungkin berubah). Juga, beberapa kutu mungkin terselip oleh crack walaupun fase testing yang selalu mendahului rilis Debian.

Untuk mengantisipasi beberapa masalah ini, Anda dapat menginstall paket apt-listchanges, yang menampilkan informasi tentang kemungkinan masalah di permulaan upgrade paket. Informasi ini dikompilasi oleh maintainer paket Debian dan dimasukkan dalam berkas /usr/share/doc/paket/NEWS.Debian untuk memberi manfaat bagi pengguna. Membaca berkas perubahan ini (melalui apt-listchanges) akan membantu Anda menghindari kejutan buruk.

You might sometimes find that the new version of a software doesn't work at all. This generally happens if the application isn't particularly popular and hasn't been tested enough; a last-minute update can also introduce regressions which are only found after the stable release. In both cases, the first thing to do is to have a look at the bug tracking system at https://bugs.debian.org/package, and check whether the problem has already been reported. If this is case, it will be also listed before the upgrade begins if you have apt-listbugs installed. If it hasn't, you should report it yourself with reportbug. If it is already known, the bug report and the associated messages are usually an excellent source of information related to the bug:

Tergantung pada keparahan kutu, versi terbaru paket mungkin telah dipersiapkan secara spesifik untuk revisi baru rilis stable. Ketika hal ini terjadi, paket perbaikan tersedia di bagian proposed-updates dari mirror Debian (lihat Bagian 6.1.2.3, “Pengajuan Pembaharuan”). Entri yang sesuai dapat ditambahkan sementara ke berkas sources.list, dan paket yang diperbaharui dapat diinstall dengan apt atau aptitude.

Terkadang paket yang diperbaiki belum tersedia di bagian ini karena tertunda validasi oleh Manajer Rilis Stable. Anda dapat memverifikasi apakah itu yang terjadi pada laman web mereka. Daftar paket belum tersedia, namun setidaknya Anda tahu bahwa proses publikasi sedang berjalan.

APT biasanya memastikan peningkatan yang bersih, menarik dependensi baru dan yang diperbarui, atau menghapus paket yang bertentangan. Tetapi bahkan alat yang hebat, itu tidak dapat mencakup semua tugas yang akan dihadapi pengguna dan administrator setelah peningkatan, karena mereka memerlukan keputusan manusia.

$ apt-show-versions | grep "No available version"

$ dpkg -l | grep ^ii | grep -i -E "(transition|dummy)"