I have the stable current release of openSUSE (12.2) on one of my desktops, I want to upgrade it to development release without downloading the DVD and doing a media upgrade.
Is it possible? How do I do that?
This is possible, and is supported on a best-effort basis.
The method to update from 12.2 to 12.3 RC1 (or RC2 or final when they are released) should be identical to the procedure described in the openSUSE wiki for upgrading from 12.1 to 12.2, just replace the numbers in the descriptions and repository URLs from 12.2->12.3 and 12.1->12.2.
If you do this then a simple zypper dup should upgrade the install to the final release on 13. march 2013 as well, as the repository URLs should not change.
If you are looking for tumbleweed then do as follows:
The only supported method of repo use for Tumbleweed is to have only the main repos (Oss, Non-oss, and Update) and the Tumbleweed repo active. For that situation a simple
will update your packages, and if any packages are ever reverted from Tumbleweed zypper dup will also handle that.
Despite it being unsupported, if you do choose to have other repos enabled, this command is safer: