@fermulator, that's on purpose, we don't have write support on /dev/md (diskfilter) devices. You might want to use /dev/sda1 instead (as per mdstat), the changes will get synced on the other drive.
I'm applying the changes for Ubuntu now, changes for Debian are in Debian git. ** Changed in: grub2 (Ubuntu) Status: Confirmed => 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/1274320 Title: Error: diskfilter writes are not supported To manage notifications about this bug go to: https://bugs.launchpad.net/grub/+bug/1274320/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs