Andreas Dilger wrote: > It would be useful to know which feature(s) that Fedora 25 enabled that > Ubuntu 16.04 didn't understand. You could use something like: > > dumpe2fs -h /dev/XXX | grep -i feature > > under Ubuntu. Typically, the code shouldn't be enabling any feature on > the filesystem without an explicit request from the admin. I expect that Ubuntu's kernel (4.4.0) supports more features than its e2fsck as I can mount it now. Ubuntu 16.04 comes with e2fsprogs version 1.42.13. The feature that that version says it doesn't support is inline_data. > Also, the "failed to mount" case should print something to the console > logs about an unsupported feature, which would help isolate the problem. Yes, it printed it couldn't mount the filesystem as ext3 originally, but I changed /etc/fstab accordingly. I have always been quite ignorant on filesystem upgrades and features supported by either the kernel or e2fsprogs and upgrades/downgrades of existing filesystems as usually everything just works. I expect that the upgrade from ext3 to ext4 was triggered by Fedora's installer (not e2fsprogs) and that dual boot configurations are less tested in general. Best regards, Julius
