In order, the answers are: yes, yes, and yes.
I have, in the past, had a number of ext2 and ext3 filesystems that I have attempted to mount with a ext4-only kernel. So far as I can remember, in every case it worked just fine. I also have used
mkfs.ext3 to create ext2/3 filesystems on that same ext4-only kernel, mounted them on that system, copied files onto the filesystem, then mounted them on older systems that did not have ext4 support at all. Basically, everything worked perfectly transparently, without my having to change much of anything (I even left the "
ext2" or "
ext3" bit in
/etc/fstab, and the kernel used the ext4 driver to mount the filesystems because I set
Copyright © 2017, Eklektix, Inc.
Comments and public postings are copyrighted by their creators.
Linux is a registered trademark of Linus Torvalds