How to Share an Opera Profile Across Systems

* Create a folder on a drive that all systems have read and write access to.

* On each system, always launch opera on the command line like this:

"path_to_opera" -pd "path_profile_folder"

You can create a shortcut that launches Opera with that command so you don't have to launch a command prompt and type the command all the time when you start Opera. Just copy an existing Opera shortcut and right-click on it and goto "properties". There you should be able to change the command that's executed when you launch the shortcut to use the -pd switch.

* Then, while Opera is running, make sure the drive the profile folder is on is never disconnected or it might corrupt the profile files, including the mail folder's files. Always make sure the Opera process completely closes before disconnecting the drive. Also, when disconnecting the drive, make sure to properly unmount it ('safely remove hardware' utility for example) so any pending writes are writting to the disk before it's disconnected.

* Also, make sure that you never try to load more than one Opera at time. If one Opera is already using the profile, the other Opera should throw an error when it tries to start. But, you should avoid trying it in the first place just in case there's a conflict between each Opera, which might cause corruption of the profile files, including the mail folder's files.

* As for using different versions of Opera with the same profile folder, you should avoid doing that unless you know both Opera's support the same settings and same version of operaprefs.ini, accounts.ini, index.ini (and all other kinds of files in the mail folder and profile folder). Mismatching Opera versions might just cause Opera to complain about the profile or might cause Opera to corruption the profile files, including the mail folder's files. Try at your own risk.

So, when using more than one Opera with the same profile, it's best to keep updated backups of the profile folder just in case something goes wrong.

* If you start Opera with the -pd switch that points to a profile folder that's on a drive that's not currently connected, Opera should just throw an error that it can't access the profile. This should be harmless and you can just connect the drive and try again.

Then, all your settings (even contacts and mail) will be synced across systems.

Note: The -pd switch doesn't work on Windows and Mac unless you're using Opera 12.00.1076 or newer.

Now, if you have an existing Opera profile that was only used on one system, you can move it to a drive that's accessible by all systems and just use the -pd switch like above.

For Linux, you'd just move the ".opera" folder in your home folder.

For a standalone installation of Opera, you'd just move the "profile" folder.

For a default Windows installation where the profile is split between "%AppData%\Opera\Opera" and "%LocalAppData%\Opera\Opera", you have to merge the files from both into a single folder in the same way a standalone installation puts the profile files all in one folder.

The only trouble you might have when moving an existing profile to work across multiple systems is with operaprefs.ini. If it contains any absolute paths for settings under "[User Prefs]", you should remove those lines so Opera uses the default relative paths inside the profile folder. (See <http://my.opera.com/operawiki/forums/topic.dml?id=1351732> for more info.)

Some threads where users have tried sharing across systems:

<http://my.opera.com/community/forums/topic.dml?id=1320512>
<http://my.opera.com/community/forums/topic.dml?id=1331972>

(There are way more that I had in mind. Just have to find them.)