What Is Android's File System? [closed] - Stack Overflow

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Learn more about Labs What is Android's file system? [closed] Ask Question Asked 14 years, 9 months ago Modified 2 years, 2 months ago Viewed 169k times Part of Mobile Development Collective 58 Closed. This question needs to be more focused. It is not currently accepting answers.

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What is Android's file system?

• android
• filesystems

Share Improve this question Follow edited Sep 9, 2018 at 17:07 Matthias Braun 34.1k2727 gold badges152152 silver badges176176 bronze badges asked Mar 11, 2010 at 0:53 GuimoGuimo 61311 gold badge55 silver badges33 bronze badges Add a comment |

9 Answers 9

Sorted by: Reset to default Highest score (default) Trending (recent votes count more) Date modified (newest first) Date created (oldest first) 39

It depends on what filesystem, for example /system and /data are yaffs2 while /sdcard is vfat.

This is the output of mount:

rootfs / rootfs ro 0 0 tmpfs /dev tmpfs rw,mode=755 0 0 devpts /dev/pts devpts rw,mode=600 0 0 proc /proc proc rw 0 0 sysfs /sys sysfs rw 0 0 tmpfs /sqlite_stmt_journals tmpfs rw,size=4096k 0 0 none /dev/cpuctl cgroup rw,cpu 0 0 /dev/block/mtdblock0 /system yaffs2 ro 0 0 /dev/block/mtdblock1 /data yaffs2 rw,nosuid,nodev 0 0 /dev/block/mtdblock2 /cache yaffs2 rw,nosuid,nodev 0 0 /dev/block//vold/179:0 /sdcard vfat rw,dirsync,nosuid,nodev,noexec,uid=1000,gid=1015,fmask=0702,dmask=0702,allow_utime=0020,codepage=cp437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro 0 0

And with respect to other filesystems supported, this is the list:

nodev sysfs nodev rootfs nodev bdev nodev proc nodev cgroup nodev binfmt_misc nodev sockfs nodev pipefs nodev anon_inodefs nodev tmpfs nodev inotifyfs nodev devpts nodev ramfs vfat msdos nodev nfsd nodev smbfs yaffs yaffs2 nodev rpc_pipefs Share Improve this answer Follow edited Oct 10, 2022 at 16:10 Matthias Braun 34.1k2727 gold badges152152 silver badges176176 bronze badges answered Mar 12, 2010 at 0:22 Diego Torres MilanoDiego Torres Milano 69.1k99 gold badges115115 silver badges143143 bronze badges Add a comment | 15

By default, it uses YAFFS - Yet Another Flash File System.

Share Improve this answer Follow answered Mar 11, 2010 at 0:58 FooleFoole 4,85011 gold badge2727 silver badges2525 bronze badges 6

• Hmm Is there any other file Systems Android supports ? – Guimo Commented Mar 11, 2010 at 1:05
• 4 Android 2.3 will use ext4. – Paul Lammertsma Commented Mar 7, 2011 at 9:43
• @PaulLammertsma Is it true that manufacturers are required to follow this? – Pacerier Commented Mar 5, 2012 at 16:42
• 1 @Pacerier I don't know the policies around what manufacturers are or aren't required to do, but a quick check on a few pre- and post-Gingerbread devices (adb shell mount) confirms that from Gingerbread the filesystem is ext4, and Froyo and older are YAFFS. – Paul Lammertsma Commented Mar 5, 2012 at 17:18
• @PaulLammertsma btw do you happen to know how to get the name of the filesystem using code? – Pacerier Commented Mar 5, 2012 at 17:39

| Show 1 more comment 13

Most answers here are pretty old.

In the past when un managed nand was the most popular storage technology, yaffs2 was the most common file system. This days there are few devices using un-managed nand, and those still in use are slowly migrating to ubifs.

Today most common storage is emmc (managed nand), for such devices ext4 is far more popular, but, this file system is slowly clears its way for f2fs (flash friendly fs).

Edit: f2fs will probably won't make it as the common fs for flash devices (including android)

Share Improve this answer Follow edited Sep 28, 2015 at 13:38 answered Mar 19, 2014 at 17:58 dolbidolbi 2,23011 gold badge2020 silver badges2525 bronze badges Add a comment | 8

Johan is close - it depends on the hardware manufacturer. For example, Samsung Galaxy S phones uses Samsung RFS (proprietary). However, the Nexus S (also made by Samsung) with Android 2.3 uses Ext4 (presumably because Google told them to - the Nexus S is the current Google experience phone). Many community developers have also started moving to Ext4 because of this shift.

Share Improve this answer Follow edited Mar 10, 2013 at 19:57 slybloty 6,49666 gold badges5252 silver badges7272 bronze badges answered Mar 2, 2011 at 17:36 BrianBrian 8111 silver badge11 bronze badge 1

• Your link is broken and I couldn't find an alternative. – slybloty Commented Mar 10, 2013 at 19:39

Add a comment | 5

since most of the devices use eMMC,the file system android uses is ext4,except for the firmware.refer-http://android-developers.blogspot.com/2010/12/saving-data-safely.html

Here is the filesystem on galaxy s4:

• /system ext4

• /data ext4

• /cache ext4

• /firmware vfat

• /data/media /mnt/shell/emulated sdcardfs

The detailed output is as follows:

/dev/block/platform/msm_sdcc.1/by-name/system /system ext4 ro,seclabel,relatime, data=ordered 0 0

/dev/block/platform/msm_sdcc.1/by-name/userdata /data ext4 rw,seclabel,nosuid,no dev,noatime,discard,journal_checksum,journal_async_commit,noauto_da_alloc,data=o rdered 0 0

/dev/block/platform/msm_sdcc.1/by-name/cache /cache ext4 rw,seclabel,nosuid,node v,noatime,discard,journal_checksum,journal_async_commit,noauto_da_alloc,data=ord ered 0 0

/dev/block/platform/msm_sdcc.1/by-name/efs /efs ext4 rw,seclabel,nosuid,nodev,no atime,discard,journal_checksum,journal_async_commit,noauto_da_alloc,errors=panic ,data=ordered 0 0

/dev/block/platform/msm_sdcc.1/by-name/persdata /persdata/absolute ext4 rw,secla bel,nosuid,nodev,relatime,data=ordered 0 0

/dev/block/platform/msm_sdcc.1/by-name/apnhlos /firmware vfat ro,context=u:objec t_r:firmware:s0,relatime,uid=1000,gid=1000,fmask=0337,dmask=0227,codepage=cp437, iocharset=iso8859-1,shortname=lower,errors=remount-ro 0 0

/dev/block/platform/msm_sdcc.1/by-name/mdm /firmware-mdm vfat ro,context=u:objec t_r:firmware:s0,relatime,uid=1000,gid=1000,fmask=0337,dmask=0227,codepage=cp437, iocharset=iso8859-1,shortname=lower,errors=remount-ro 0 0

/data/media /mnt/shell/emulated sdcardfs rw,nosuid,nodev,relatime,uid=1023,gid=1 023 0 0

Share Improve this answer Follow edited Sep 9, 2014 at 20:17 answered Sep 8, 2014 at 0:59 rupesh jainrupesh jain 3,43011 gold badge1515 silver badges2222 bronze badges 1

• I have just had a corrupted file system on both cache and system partitions. Shall I just reformat them as f2f? – Elysium Commented Jan 12, 2016 at 14:46

Add a comment | 4

Depends on what hardware/platform you use.

Since Android uses the Linux-kernel at this level, it is more or less possible to use whatever filesystem the Linux-kernel supports.

But since most phones use some kind of nand flash, it is safe to assume that they use YAFFS.

But please note that if some vendor wants to sell a Android netbook (with a harddrive), they could use ext3 or something like that.

Share Improve this answer Follow answered Mar 11, 2010 at 13:40 JohanJohan 20.7k2828 gold badges9595 silver badges110110 bronze badges 1

• 1 not ext3. its not good embedded devices – Droidme Commented Oct 29, 2012 at 6:46

Add a comment | 2

When analysing a Galaxy Ace 2.2 in a hex editor. The hex seemed to point to the device using FAT16 as its file system. I thought this unusual. However Fat 16 is compatible with the Linux kernel.

Share Improve this answer Follow answered Nov 9, 2012 at 10:16 MichaelMichael 2111 bronze badge Add a comment | 0

Similar to Linux:

• /boot

• /system

• /recovery

• /data

• /cache

• /misc

Share Improve this answer Follow edited Jun 25, 2019 at 4:26 Bulat 71677 silver badges1515 bronze badges answered Jul 7, 2018 at 10:55 Mario PierreMario Pierre 922 bronze badges Add a comment | -2

Android supports all filesystems supported by the Linux kernel, except for a few ported ones like NTFS.

The SD card is formatted as ext3, for example.

Share Improve this answer Follow edited Oct 11, 2020 at 13:31 CommunityBot 111 silver badge answered Mar 11, 2010 at 17:30 Peter vdLPeter vdL 4,9931010 gold badges4242 silver badges6161 bronze badges 3

• 15 No, the sd card is using a fat-based filesystem, else it wouldn't be mountable by Windows. Most sd cards are formatted as fat32, although you might stumble upon small sd cards (<1GB) that can get away with using fat16. – Robert Commented Feb 26, 2011 at 8:42
• 1 You're right Robert - sorry for the goof. – Peter vdL Commented Feb 26, 2011 at 23:40
• You also didn't answer the question that was asked: "What is Android's file system?" The original poster wasn't asking what filesystems Android supports but what filesystem(s) it is installed on. – FlexMcMurphy Commented Dec 27, 2021 at 21:01

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