Which ext4 features will be missing on a filesystem upgraded from ext3 to ext4 using the instructions here?

The text explains:

There are additional ext4 features, such as flex_bg and > 16TB filesystem support that can only be enabled at format time via mke2fs.

The "such as" implies there are other features too. Does anyone know of a list?


extents are one of them too, only new files will be created in extents format. In any case if you can reformat the partition rather than upgrade it, it's better to do so, fragmentation will get back to approximately 0 whatever the amount you have on your ext3 FS now.


There are some things listed on the link you give, like no backward compatibility (and no extents which is the normal reason for not being able to mount as ext3).

Wikipedia lists many things that your link doesn't mention (what this means is anyones guess). I would want to recreate the partition from scratch to have all of the benefits, without the downsides of an upgrade which isn't perfect.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.