參考資訊：
https://forum.xda-developers.com/t/tutorial-create-internal-storage-backup-in-twrp.3389172/
步驟如下：
Step 1. reboot in recovery Step 2. mount all partitions Step 3. now open file manager Step 4. go to path /data/media Step 5. now rename media folder name to xyz (now path name is /data/xyz) Step 6. now go to backup window Step 7. now refresh memory.... u notice that data partition memory is increase (data+internal storage) Step 8. connect pendrive through otg cable... mount otg Step 9. now go agaitin backup window....n start backup...... now your all photo,video all are safe in pendrive...njoy Note 1. plz rename xyz to media after backup 2. don't reboot phone before rename 3. plz don't try to wipe data while name of folder is xyz 4. ^^^^^ if u want to restore that backup than wipe all data,cache,internal and try restore n after restore complete.....rename xyz to media n reboot....