unfortunately the boot partition of my SD card got corrupted some days ago. I had to set up my YunoHost server again from the start. I could use a backup so I only lost one week of data.
Now I am missing one week of interesting GPS tracks from my holiday trips.
Before resetting my server I could extract almost every file of the files partition. So I guess I have all the GPS data that was recorded by the app ulogger.
I am using the app phpmyadmin and so I can see that the data of ulogger is stored in a database.
Does anybody know where this database is stored and if there is a way to extract the data from the files I have extracted from my corrupted SD card?
What an unfortunate story, glad you got most files back/backed up.
On my Yunohosts (with default settings), the data files are at /var/lib/mysql
In that directory there are subdirectories per database, and in there are the tablespaces and data. Those are the files you have recovered, but they are no drop-in replacement for your new installation of ulogger.
I had the same problem once, and was successful at restoring Wordpress from bare datafiles using a post found at Stack Exchange. The process was unfortunately sufficiently complex that I have not yet worked out my notes into a readable format.
Back then I had the benefit of low usage of the server, so that I could reinstall (and backup) the app multiple times without bothering too many people.
The trick is to make MySQL believe that it actually is the MySQL running the old installation. Then you can make a proper backup of your data, and finally import it again in the new installation.
In my case I restored all I had from backup, and then made a backup of that again so that I had a throw-away installation of the database (actually, the whole Yunohost to be safe).
You will need the recovered files of the mysql-directory as well as those of your ulogger-directory.
Alternatively you could open the files with a text editor and find your GPS-data in one or more of the ibd-files.
Sorry to have nothing near a copy/paste howto; I’ll try to be of help if I can (I might not be online that much the next couple of days though).
Thank you very much for your help. You’re right - these are the correct files. Unfortunately I don’t have them. All folders in /var/lib/mysql are empty in my backup. Seems like there was a problem with the user rights and they weren’t copied from my SD card. I had problems on several folders and tried to fix them one by one. But I must have missed that folder.
Have you put your SD card to another use by now? Software such as photorec can recover a lot from corrupted cards. Depending on how attached you are to the GPS tracks, it might be worth a try.
You will end up with a huge amount of partial files as well though, so you’d have to search in the result files for some known good strings related to GPS tracks.
The SD card is used in my Raspberry again with a new installation of YunoHost installed on June 12th. I don’t believe there will be something left to use…
I remember searching very hard for a file or folder with the name mysql. It some weeks ago and the fragments of my SD card are stored in a messy way on a notebook. Chances are very small, but maybe some day I could find it.
But I think it’s best to accept that they’re lost.
