Canonical please read Theodore Tso's Comment #4 above, and consider for Ubuntu 18.04 LTS!
This "64bit,metadata_csum" creates compatibility-issues even with 16.04 LTS, and does not seem to provide a huge benefit [>16TB fs support, slightly stronger metadata checksumming]. This creates all sorts of problems for compatibility/portability of filesystems, e.g.:- * dual-booting 18.04, even previous LTS version cannot fsck the filesystem. * "ext4 portable disks" created by 18.04 similarly same problem. * Also consider how wide is the 64bit,metadata_csum support anyway, users may want disks to work with many distros/drivers? Canonical's commercial-supporters may have views herein?. -- the linked bugreport also mentions another issue with hwe-edge and LVM. Also note, turning off the 64bit,metadata_csum when required is a total PAIN, needing filesystem offline, fsck and tune2fs in careful concert..... In my view, the 16.04 LTS mke2fs.conf [ ext4{} stanza with "auto_64-bit_support = 1" and NO "64bit,metadata_csum" in "features" ] should be seriously-considered for 18.04 "LTS" (even if 18.10 onwards follow Debian). As tytso says, this 'change' has been "Decision-by-Default" due to importing a Debian upstream package, I would like Canonical to make an 'informed and considered decision' about this please!. Hope that helps! -- 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 sets metadata_csum option on ext4 partition which is incompatible with other LTS Ubuntu versions 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 : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp