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.
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.
