FWIW, As was discussed, I checked into Grub2 and os-prober in older supported ubuntu (which may have similar incompatibility to e2fsprogs, thereby creating a multibooting issue with 18.04). After experimenting carefully with a 14.04+16.04+18.04 (GA kernels, no HWE specifically) BIOS-style triple boot, can confirm the grub ext4 support is all cross-compatible (14.04 can autodetect and boot 64bit,metadata_csum 18.04 from its' own grub2).
However, e2fsprogs is DEFINITELY an issue as above, definitely worth sorting-out whatever-happens to the 18.04 default filesystem options, in my view. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to e2fsprogs in Ubuntu. https://bugs.launchpad.net/bugs/1365874 Title: Ubuntu 12.04 LTS, 14.04 LTS, 16.04 LTS do not support ext4 metadata checksumming Status in e2fsprogs package in Ubuntu: Triaged Bug description: In the Trusty release notes "Metadata checksumming" is listed as one of the tech highlights of kernel 3.13. https://wiki.ubuntu.com/TrustyTahr/ReleaseNotes#New_features_in_14.04_LTS However, the userland tools do not support this kernel feature. To the best of my knowledge this will be supported in 1.43, and won't be backported to 1.42. IMHO this is very misleading. It's like a car salesperson sold you a sports car with an V8 engine. After you drove it home, you opened the hood and realized only 6 cylinders are working because 2 of the spark plugs were not included, and you have to buy aftermarket ones. <rant>BTW, I've been following the development of e2fsprogs for over a year. 1.43 release has been in limbo for God knows how long :( </rant> To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/e2fsprogs/+bug/1365874/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp