Yifei Kong

May 29, 2017

安卓的文件系统

let's assume /system is the rom folder

Partition Explanation
/boot kernel & Co.
/cache app cache
/data user data partition¹
/data/data app data¹
/dev devices, virtual fs
/mnt/asec encrypted apps (App2SD)
/mnt/emmc internal sdcard³
/mnt/sdcard external sdcard³
/proc process information²
/recovery used in recovery mode
/system system ROM (read-only)

/data and /data/data

These are in most cases two separate partitions, but there might be cases where this is handled otherwise. One thing they have in common (add /cache here as well): they get wiped on a factory-reset, while the other partitions are usually left untouched by that.

Directory Explanation
/data/anr traces from app crashes (App Not Responding)
/data/app .apk files of apps installed by the user
/data/backup Googles Cloud-Backup stuff
/data/dalvik-cache optimized versions of installed apps¹
/data/data app data²
/data/local temporary files from e.g. Google Play³
/data/misc system configuration (WiFi, VPN, etc.)
/data/system more system related stuff (certs, battstat)
/data/tombstones more crash stuff ("core dumps")
/data/user multi-user support, /data/user/0 is a symlink to /data/data

Reference

[1] http://android.stackexchange.com/questions/46926/android-folder-hierarchy [2] http://android.stackexchange.com/questions/48393/what-kind-of-data-is-stored-in-data-user-directory