Appendix A. Managing your jessie system before the upgrade

Basically this is no different from any other upgrade of jessie you've been doing. The only difference is that you first need to make sure your package list still contains references to jessie as explained in Section A.2, “Checking your sources list”.

If you upgrade your system using a Debian mirror, it will automatically be upgraded to the latest jessie point release.

If any of the lines in your /etc/apt/sources.list refer to “stable”, it effectively points to stretch already. This might not be what you want if you are not ready yet for the upgrade. If you have already run apt-get update, you can still get back without problems by following the procedure below.

If you have also already installed packages from stretch, there probably is not much point in installing packages from jessie anymore. In that case you will have to decide for yourself whether you want to continue or not. It is possible to downgrade packages, but that is not covered here.

Open the file /etc/apt/sources.list with your favorite editor (as root) and check all lines beginning with deb http:, deb https:, deb tor+http:, deb tor+https: or deb ftp:^[6] for a reference to “stable”. If you find any, change stable to jessie.

	Note
	Lines in sources.list starting with “deb ftp:” and pointing to debian.org addresses should be changed into “deb http:” lines. See Section 5.1.2, “FTP access to Debian hosted mirrors will be removed”.

If you have any lines starting with deb file:, you will have to check for yourself if the location they refer to contains an jessie or a stretch archive.

	Important
	Do not change any lines that begin with deb cdrom:. Doing so would invalidate the line and you would have to run apt-cdrom again. Do not be alarmed if a cdrom: source line refers to “unstable”. Although confusing, this is normal.

If you've made any changes, save the file and execute

# apt-get update

to refresh the package list.

Before upgrading your system to stretch, it is recommended to remove old configuration files (such as *.dpkg-{new,old} files under /etc) from the system.

Using a legacy non-UTF-8 locale has been unsupported by desktops and other mainstream software projects for a long time. Such locales should be upgraded by running dpkg-reconfigure locales and selecting a UTF-8 default. You should also ensure that users are not overriding the default to use a legacy locale in their environment.