Can we pay-attention, to this thread (now) being about considering the feature-flags 'used by default' in mke2fs.conf, in consideration to 18.04 -- [linked bug for e2fsprogs].
We know massive 'compatibility'/portability benefit of formatting the same as previous-LTS by default, as the required e2fsprogs was only introduced 16.10, and the needed kernel was only in 16.04 (and 14.04 -HWE-kernel-update.). NB: Looks like there is a similar issue with GRUB2 which affects dual-booters, grub2 2.02beta3 may be needed to support 64bit FS. If so, again Xenial isn't compatible to detect an 18.04 in multi-boot-menu. I'd like tytso to comment on the downsides of formatting without 64bit,metadata_csum, more specifically. From what I can (see) this only loses a little extra checksumming-integrity (against bad disks, which we've never needed before??), and the 64bit feature appears only to be needed to strengthen these checksums or support >16TB disks (bearing in mind auto_64bit_support can still be used). NB: Is this correct, -OR- is there likely going to be future annoyances with 'other' ext4 features-to-come which will ALSO expect 64bit formatting?. My suggestion is, this hasn't been sorted-out enough in the ubuntu- world, and 64bit,metadata_csum should be disabled-by-default for 18.04 and backporting grub/e2fsprogs/etc where relevant should happen as well [see other thread, possibly another may be created for grub2]. -- 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/1601997 Title: Ubuntu 16.10+ installer uses ext4 feature 'metadata_csum' which is incompatible with older (LTS) e2fsprogs Status in e2fsprogs package in Ubuntu: Triaged Bug description: Ubuntu 16.10 installer sets metadata_csum option on ext4 partition which is incompatible with other LTS Ubuntu versions (12.04 LTS, 14.04 LTS, 16.04 LTS). Steps to reproduce: 1. Download Ubuntu 16.10 installation media. 2. Install Ubuntu. 3. Try to do fsck -fy /dev/sdX1 from other supported Ubuntu distro. Expected results: User can check and fix errors on ext4 filesystem, created on Ubuntu 16.10. Actual results: User can not check and fix errors on ext4 filesystem because of lack of 'metadata_csum' option in previous LTS Ubuntu versions. The only one working solution was to scan from 16.10 live install media. Note: it is known, that Dan Watkins disabled metadata_csum when creating ext4 filesystems ( see http://bazaar.launchpad.net/~daniel-thewatkins/maas-images/fix-yakkety-builds/revision/305 ). It is good solution. ProblemType: Bug DistroRelease: Ubuntu 16.10 Package: e2fsprogs 1.43.1-1 ProcVersionSignature: Ubuntu 4.4.0-30.49-generic 4.4.13 Uname: Linux 4.4.0-30-generic i686 ApportVersion: 2.20.2-0ubuntu1 Architecture: i386 CurrentDesktop: Unity Date: Mon Jul 11 23:42:49 2016 SourcePackage: e2fsprogs UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/e2fsprogs/+bug/1601997/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
