What is Android's file system? [closed]

Question

What is Android's file system?

Answer 1

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

Answer 2

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

Answer 3

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.

Answer 4

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

Answer 5

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.

Answer 6

Similar to Linux

/boot

/system

/recovery

/data

/cache

/misc