According to the btrfs document[1], adding another disk to the existing btrfs file system is equivalent to create a raid with Raid 1 on Meta, Raid 0 on Data group (mkfs.btrfs -m raid1 -d raid0).
So when wiping one of the disks out, it will corrupt the data but the meta should be OK: # btrfs fi show Label: none uuid: 3e7e0fb5-5fec-4938-bc20-0e5dfdf466ff Total devices 2 FS bytes used 128.00KiB devid 1 size 512.00MiB used 88.00MiB path /dev/loop0 *** Some devices missing This behaviour in this test case has been changed in the kernel with commit 4330e183c9537df20952d4a9ee142c536fb8ae54, we should be able to mount the drive with 'rw' in degraded mode, unless the data chunk was destroyed. [1] https://btrfs.wiki.kernel.org/index.php/Using_Btrfs_with_Multiple_Devices ** Changed in: ubuntu-kernel-tests Assignee: (unassigned) => Po-Hsu Lin (cypressyew) ** Changed in: ubuntu-kernel-tests Status: New => In Progress -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1809870 Title: 2365dd3ca02bbb6d3412404482e1d85752549953 in ubuntu_btrfs_kernel_fixes failed on B To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-kernel-tests/+bug/1809870/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs