It appears that it's always been a touch racy. Curtin does not create bcaches like the script does (make-bcache --wipe-bcache -C /dev/sdc -B /dev/sdb), rather we make the cache-dev and backing dev separately, and then attach them by echoing the cacheset uuid into the bcache device attach sysfs file. The issue is after install when we first boot the system that has one or more bcache devices, we *sometimes* don't see the /dev/bcache/by-uuid symlinks show up.
Focal _always_ fails; Eoan works sometimes, in our testing, bionic has never failed; though clearly it suffers from the same (or similar) race. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1861941 Title: bcache by-uuid links disappear after mounting bcache0 Status in linux package in Ubuntu: New Status in linux-signed-5.4 package in Ubuntu: New Bug description: 1. root@ubuntu:~# lsb_release -rd Description: Ubuntu Focal Fossa (development branch) Release: 20.04 2. root@ubuntu:~# lsb_release -rd Description: Ubuntu Focal Fossa (development branch) Release: 20.04 root@ubuntu:~# apt-cache policy linux-image-virtual linux-image-virtual: Installed: 5.4.0.12.15 Candidate: 5.4.0.12.15 Version table: *** 5.4.0.12.15 500 500 http://archive.ubuntu.com/ubuntu focal/main amd64 Packages 100 /var/lib/dpkg/status root@ubuntu:~# apt-cache policy linux-image-5.4.0-12-generic linux-image-5.4.0-12-generic: Installed: 5.4.0-12.15 Candidate: 5.4.0-12.15 Version table: *** 5.4.0-12.15 500 500 http://archive.ubuntu.com/ubuntu focal/main amd64 Packages 100 /var/lib/dpkg/status 3. mount /dev/bcache0 && ls -al /dev/bcache/by-uuid/ + ls -al /dev/bcache/by-uuid/ total 0 drwxr-xr-x 2 root root 60 Feb 4 23:31 . drwxr-xr-x 3 root root 60 Feb 4 23:31 .. lrwxrwxrwx 1 root root 13 Feb 4 23:31 abdfd1f6-44ce-4266-91db-24667b9ae51a -> ../../bcache0 4. root@ubuntu:~# ls -al /dev/bcache/by-uuid ls: cannot access '/dev/bcache/by-uuid': No such file or directory ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: linux-image-5.4.0-12-generic 5.4.0-12.15 ProcVersionSignature: Ubuntu 5.4.0-12.15-generic 5.4.8 Uname: Linux 5.4.0-12-generic x86_64 ApportVersion: 2.20.11-0ubuntu16 Architecture: amd64 Date: Tue Feb 4 23:31:52 2020 ProcEnviron: TERM=xterm-256color PATH=(custom, no user) LANG=C.UTF-8 SHELL=/bin/bash SourcePackage: linux-signed-5.4 UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1861941/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp