I have the same problem with Precise Pangolin 12.04 Alpha 1 and a btrfs partition : immediately after the BIOS screen, I see a message "error: sparse file not allowed". After a few seconds, the Linux boots starts successfully.
I have the same problem with Precise Pangolin 12.04 Alpha 1 and a btrfs partition : immediately after the BIOS screen, I see a message "error: sparse file not allowed". After a few seconds, the Linux boots starts successfully.