Since on that machine i have all the Slackware repository for 12.2 up until 14.0 (and even -Current), it's so easy to do so. I just changed the default configuration of slackpkg to use DOWNLOAD_ALL=on just to make sure everything is downloaded before attempting to upgrade the packages. Next is updating the mirror location to the local files and change it to Slackware 13.0 and ran
- slackpkg update gpg
- slackpkg update
- slackpkg install-new
- slackpkg upgrade-all
- slackpkg clean-system
I continued with Slackware 13.1, 13.37, and finally 14.0. These upgrade steps must be done one by one. You can't jump from 12.2 to 14.0 directly or else you might skip some important packages between those two versions.
There are some packages that will not work until you reboot your system and your kernel is updated with a new one. One of them is apr-* packages which is a dependency of httpd (apache web server).
Right now, the server is running on Slackware 14.0 and i'm planning to upgrade to Slackware 14.1 once it's released (it should be released soon).
Big thanks to slackpkg to make my upgrade process went so smooth :)