105
All apps (root or not) have a default data directory, which is /data/data/<package_name>. By default, the apps databases, settings, and all other data go here. If an app expects huge amounts of data to be stored, or for other reasons wants to "be nice to internal storage", there's a corresponding directory on the SDCard (Android/data/<package_name&...
38
First, you need to be aware of two facts:
Android uses more than one file system (think of "multiple drives/partitions" when comparing with your computer
while sharing a common base, directory structures might differ between manufacturers
So as starting points, I further recommend the file-system tag-wiki and the partition tag-wiki (you might ...
30
I usually use a combination of the following 4 commands and correlate them, since each of these commands gives a piece of the information that might be needed.
Summarily:
Using df lists the filesystem path alias and size info as seen below (total size, used, free and block size)
Example output:
root@ks01lte:/sdcard # df
df
Filesystem ...
30
There is no singularly defined "Android" filesystem, so this can vary between devices. Any FS that the kernel can load drivers for is basically fair game.
By and large, you'll almost certainly find that ext4 is the most common filesystem on modern devices. Older devices may use older ext* versions as well, or other filesystems entirely. Since everything is ...
25
/data/user was added in Jelly Bean as part of multi-user support. Each user on the device gets a directory in there named after their user ID, and that directory contains each app's data directory for that user. /data/user/0 is a symlink to /data/data.
24
That has to do with the Multi-User feature enabled with JellyBean 4.2 (not 4.1). In order to handle separate accounts, parts of the directory structure had to be changed. /sdcard/legacy e.g. always points to the currently logged-in user's sd card directory.
I currently cannot find the document where I read the details, so I cannot link any source. But with ...
20
Some major changes occurred to storage in Android 4.4 (see Android's Storage Journey). So the following is generally true for Android 4.4+ and particularly 6+.
This is from my detailed answer to How disk space is used on Android device?. Apps' files are saved (by system and app itself) to internal and external storage under different categories.
DIRECTORY ...
20
This is a known issue. Go to app manager and find 'external storage' and 'media storage' and clear data and cache for them, then reboot, and wait up to 10 minutes and then connect to PC via USB.
Sometimes media scan apps from play store help if you don't want to reboot.
18
You can fix this with the help of root and a terminal emulator (e.g. Android Terminal Emulator (or, alternatively, using adb shell). The binary to do the job is called fsck, and usually located in either /system/xbin or /system/bin. Sometimes you need a special variant of it, which might e.g. be called fsck.exfat or the like. So first let's make sure we find ...
18
The answer to your question is built into your phone's OS.
1. Put the SD card in your phone
2. Reformat the SD card with your phone(Settings --> Storage/Storage & USB)
3. The file system on the freshly formatted SD card is the type that will give you the best performance with your phone.
4. Outside the context of your phone the optimum file system is ...
15
The solution was to reboot the phone. The com.fsck.k9 directory is now visible on the top level of the phones file system.
14
The syntax of mount command usually requires you specify the target:
mount -o remount,rw /system /system
This output could be useful for us to better understand your problem:
cat /proc/mounts
As a last resort, as you have root you can try saving raw image of system, mount it on your box and push the app there, then flash it back on your device. To save ...
13
The sequence of commands that worked for me was
adb root
adb disable-verity
adb reboot
adb root
adb remount
If I don't reboot, remount does not succeed.
11
The Android system does not have the conventional /etc/passwd storage for users and groups. In android, user and groups are used to isolate processes and grant permissions. The Android system creates a user per application when an application gets installed. Hence application data files are stored in /data/data/<app-name>/, and are read-writable only ...
10
Here's a helpful piece of info also.
This is the absolute path to SMS and MMS DB on most android devices:
/data/data/com.android.providers/telephony/databases/mmssms.db
9
Looks like it moved to data/User_DE/0/com.android.providers.telephony/databases with Nougat.
At least, this is where it can be found on my Nexus 6. Hope this helps.
9
Note that, as of Kitkat (Android 4.4, released Sept 2013), the default path changed from:
/data/data/com.android.providers/telephony/databases/mmssms.db
to
/data/data/com.android.providers.telephony/databases/mmssms.db
Update: As mentioned in the comments, the latter path already exists in JB.
9
After a lot of trial and error, I discovered that the Android/obb folder is automatically shared among users.
It's not ideal, but it's better than a cloud storage option for large files.
9
The answer to your question you are asking is too big. I can, however, give you a basic answer which covers the basics.
There are two kinds of apps:
Root and non-root.
Root apps can basically store/modify files wherever they want.
Non-root apps can only store/modify files here: /sdcard/ and every folder what comes after.Mostly, the installed apps store ...
9
Even it does not fully answer the question, here's a guide to decrypt the external storage formatted as internal. You do need to be root on your phone, however.
The gist is that we search for strings including the keyword expand and ending with .key within vold using:
$ strings vold|grep -i expand
--change-name=0:android_expand
%s/expand_%s.key
/mnt/expand/...
9
I'm going to give a general overview of how dm-verity and related things work on Android according to my limited knowledge. Situation might differ on different devices and ROMs.
HOW IS DM-VERITY ENFORCED?
dm-verity (Verified Boot and AVB) as well as dm-crypt (FDE) are targets of device-mapper feature of Linux kernel. dm-verity verifies the integrity of ...
8
The fstab file is in /.
It's called /fstab.$systemname.rc where $systemname is based on the handset's fingerprint property, either identified as category of chipset or handset itself.
8
Sockets and pipes represent Unix' way of inter process communication, and a communication channel has no point in having a size. Sockets are thus not seekable as in go to position x in the file.
Linux (which Android makes use of) has 7 file types:
Regular Files
Directories
Character Device Files
Block Device Files
Local Domain Sockets
Named Pipes
Symbolic ...
8
LOST.DIR is just a storage space (directory) for files that were recovered upon boot. You can safetly remove it with no problems. The sysytem keeps it just in case you want to get your recovered currupted files back.
A quick google search yielded:
LOST.DIR - what is it?
As for preventing it from being created, just prevent the SD card from becoming ...
8
The filesystem support is device-specific, and in fact many devices using Android 2.3 support ext3 in the kernel (or ext4, which can also mount ext3 and ext2 filesystems).
Usually the difference in filesystem support is due to different hardware. Older devices often used raw NAND flash chips and MTD drivers in Linux, which did not support conventional ...
8
I installed the Disk Info app and in the options, I enabled Expert mode and Unmounted partitions. It doesn't say "swap", but it shows clearly that it's the only other partition on the SD card and it's the right size, so /dev/block/mmcblk1p2 must be the one:
Swapper 2 is configured to use /dev/block/mmcblk0p3 by default, so I'm glad I didn't go with the ...
8
fdisk -l works if you pass the whole disk device name explicitly (e.g., fdisk -l /dev/block/mmcblk1); what does not work is automatic discovery of block devices (apparently because Android places block device files under the /dev/block directory, but fdisk expects to see those files directly in /dev). Therefore one option is to collect the list of whole disk ...
8
DiskInfo displays this information (among other things) when you select a partition to view its details. Works with the internal partitions on my Nexus 5, but should also support external SD cards and the like:
8
In the settings of Google Play Music, if you have it set to cache on the external SD card, your cache location will be /external_sd/Android/data/com.google.android.music/files/music/.
If you have it use the internal storage, the path will be /sdcard/Android/data/com.google.android.music/files/music.
Note that these files are named [some-id].mp3, like 124....
7
There's a big chapter on that in Andrew Hoog's Android Forensics book on that (see this Amazon list for available copies). Unfortunately, that book doesn't come for free (but from Elsevier; so prices range from ~USD 20 for the Kindle edition to ~USD 50 for the print, with some crazy offers for ~USD 170+ as well), but it explains a lot of background not only ...
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