Is it possible to change the File-System of usb without loosing data and without taking backup?

Question

As the subject says, Can I change the file-system of a usb (or say any drive) from it's current partition like :- ext4 to a different partition like:- ext2/fat/ext3/ntfs file-system without loosing the data in the drive and without taking backup.

Answer 1

From File system Wiki

On Linux, ext2 can be converted to ext3 (and converted back), and ext3 can be converted to ext4 (but not back), and both ext3 and ext4 can be converted to btrfs, and converted back until the undo information is deleted.These conversions are possible due to using the same format for the file data itself, and relocating the metadata into empty space, in some cases using sparse file support.

So it seems it is not Back-Convert-Compatible and Converting from ext4 to NTFS will require Formatting , since they are totally different File-systems , also holds true for ext4 to Fatxx format .That means without data loss

ext2 >> ext3 possible

ext3 >>ext4 possible

ext3 & ext4 >> btrfs possible

ext4 >> ntfs not possible w/o Format

ntfs >> extX not possible w/o format

Please refer this question on superuser also.

Answer 2

The simple answer is that it depends on which filesystem you are "converting" from & to. There needs to be a specific program to convert it for you.

For example, a FAT16 or FAT32 filesystem on Windows can be converted to NTFS via the Windows "convert" command. However, generally you cannot convert filesystems.

1 other option that may work though: Ext4 filesystems can often (but not always) be mounted as ext3 or ext2. Similarly, Ext3 filesystems can often be mounted as ext2. e.g., on windows, I mount Ext3 & Ext4 filesystems using the ext2 driver ext2fsd: