The default satellites.xml is in the image, and is under version control. So it will be overwritten everytime you do an update.
This is the standard situation:
-rw-r--r-- 1 root root 531573 Jun 6 02:01 /etc/tuxbox/satellites.xml
lrwxrwxrwx 1 root root 26 Jun 9 19:28 /etc/satellites.xml -> /etc/tuxbox/satellites.xml
lrwxrwxrwx 1 root root 26 Jun 9 19:28 /usr/share/satellites.xml -> /etc/tuxbox/satellites.xml
lrwxrwxrwx 1 root root 26 Jun 9 19:28 /usr/share/tuxbox/satellites.xml -> /etc/tuxbox/satellites.xml
You see that /etc/tuxbox is the file that is provided by the image and is versioned, the others are not present by default, and are symlinked to the versioned file.
If you have a custom file, you should place it in /etc/enigma2, and it will take precendence over the system file in /etc/tuxbox. If you don't, and overwrite the system file, it will be removed and overwritten with a new system the next time you run an update.
Currently in use: VU+ Duo 4K (2xFBC S2), VU+ Solo 4K (1xFBC S2), uClan Usytm 4K Ultimate (S2+T2), Octagon SF8008 (S2+T2), Zgemma H9.2H (S2+T2)
Due to my bad health, I will not be very active at times and may be slow to respond. I will not read the forum or PM on a regular basis.
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