On my "8GB" device (which I believe doesn't have an extra physical sdcard installed (I have to unscrew it to see that)) I have the following df output:
Filesystem Size Used Free Blksize /dev 402M 32K 401M 4096 /mnt/secure 402M 0K 402M 4096 /mnt/asec 402M 0K 402M 4096 /mnt/obb 402M 0K 402M 4096 /mnt/shm 1024K 0K 1024K 4096 /system 503M 297M 206M 4096 /data 6G 344M 5G 4096 /cache 495M 186M 309M 1024 /device 7M 1M 6M 1024 /storage/sdcard0 6G 344M 5G 4096
I am confused though, because /data and /storage/sdcard0 are exactly the same (suspiciously the same!), but as I understand it though: /storage/sdcard0 should refer to an external physical sd-card, and not refer to the same place as /data. What is going on?