Backup of the \/home directories.<\/span><\/p>\n tar -pczf home.tar.gz \/home<\/span><\/p>\n For ISPConfig 3 users: Backup of your email server files.<\/p>\n tar -pczf vmail.tar.gz \/var\/vmail<\/span><\/p>\n Backup MySQL databases.<\/p>\n mysqldump –defaults-file=\/etc\/mysql\/debian.cnf -cCeQ –hex-blob –quote-names –routines –events –triggers –all-databases -r all_databases.sql<\/p>\n Then move the tar.gz and .sql\u00a0files for safe storage on a backup drive.<\/p>\n We will install all available\u00a0Jessie updates first before we upgrade to Jessie. On some systems, the package source is defined as “stable” in the sources.list file instead of “jessie” or “stretch”. To avoid an accidental early upgrade to Stretch, please check the sources.list now and ensure that it contains “jessie” and not “stable” as source:<\/p>\n Use a command line editor like nano or vi to open\u00a0\/etc\/apt\/sources.list,<\/span>\u00a0the lines should be similar to the ones below:<\/p>\n nano\u00a0\/etc\/apt\/sources.list<\/p>\n The following commands will install all pending\u00a0Jessie updates. This ensures that your system is in a good shape for the update to Stretch.<\/p>\n apt-get update<\/p>\n Ready for the first upgrade:<\/p>\n apt-get upgrade<\/p>\n Follow this with:<\/p>\n apt-get dist-upgrade<\/p>\n This test\u00a0is important, we will check the package state to ensure that no packages are on hold or in half installed state. Your system and apt database must be in a good shape before we proceed with the dist upgrade. If there are any broken or “on hold” packages, then fix these issues before the\u00a0upgrade.<\/p>\n Check that no packages are on hold by querying the package database with the dpkg command:<\/p>\n dpkg –audit When both commands did not return any packages, then proceed with the upgrade.<\/p>\n Edit\u00a0the \/etc\/apt\/sources.list<\/span>\u00a0file again:<\/p>\n nano\u00a0\/etc\/apt\/sources.list<\/p>\n and replace its content with the following lines:<\/p>\n Save the file and run the following command to update the sources database:<\/p>\n apt-get update<\/p>\n We can test with apt command if the installed packages are upgradable. Run this command to perform the test:<\/p>\n \u00a0apt list –upgradable<\/p>\n It is recommended to do the upgrade in two steps, first run “apt-get upgrade” to install the base packages and then run “apt-get dist-upgrade” to do the actual distribution upgrade,<\/p>\n Start with the update by running this command:<\/p>\n apt-get upgrade<\/p>\n Next, we will do the distribution upgrade by running:<\/p>\n apt-get dist-upgrade<\/p>\n A reboot is required to finish the upgrade and load the new kernel:<\/p>\n reboot<\/p>\n To check which Debian version is currently installed on the system, take a look at the file \/etc\/os-release.<\/p>\n cat \/etc\/os-release<\/p>\n The result on a\u00a0Debian\u00a0Stretch system is:<\/p>\nCheck the\u00a0apt sources.list file<\/h2>\n
deb http:\/\/httpredir.debian.org\/debian jessie main contrib non-free
Update the packages for Debian 8<\/h2>\n
Check the package state to ensure that no packages are on hold or in half installed state<\/h2>\n
dpkg –get-selections | grep hold<\/p>\nUpdate the sources.list for Debian 9<\/h2>\n
deb http:\/\/httpredir.debian.org\/debian stretch main contrib non-free
Check if packages are upgradable<\/h2>\n
Debian 8 to 9 Update in two steps<\/h2>\n
Check the update<\/h2>\n
![\"Debian](\"https:\/\/www.howtoforge.com\/images\/wheezy_to_jessie_update\/big\/debian-8-to-9-upgrade.png\" "\\"\\"")
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