(Post edited to add more info.)
My Android phone contains, in the lowest user-accessible directories of both phone storage and SD card, several small files named xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx where x is a hex digit.
There are three of them in the phone storage
/sdcard (all zero size), owned by
root:sdcard_rw and mode 664. And there are six in the external SD card
/mnt/extSdCard (some zero size, some 36 bytes long), owned by
system:media_rw and mode 775. Dates range from 2013 to one week ago.
All files are readable, and those who aren't empty contain only a string which is identical to the filename.
I was curious to know what is the purpose of these files and if they can be deleted safely.
Is it a coincidence that they have the same format as an UUID?