I, too, have "lost" my other Ubuntu partition. I installed 12.04 on sda1 using Btrfs; it booted fine. Then I installed another 12.04 on sda2 (/boot) and sda3 (swap) and sda4 (/), and it boots fine, but now I can't boot from sda1. Mounting and then unmounting sda1 as suggested in comment #2 does not help.
$ sudo fdisk -l /dev/sda Disk /dev/sda: 128.0 GB, 128035676160 bytes 255 heads, 63 sectors/track, 15566 cylinders, total 250069680 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00076ab2 Device Boot Start End Blocks Id System /dev/sda1 * 2048 13672447 6835200 83 Linux /dev/sda2 * 13672448 14258175 292864 83 Linux /dev/sda3 14258176 24023039 4882432 82 Linux swap / Solaris /dev/sda4 24023040 250068991 113022976 83 Linux $ sudo os-prober $ -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/674841 Title: os-prober 1.40 doesn't detect another ubuntu installation anymore To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/os-prober/+bug/674841/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
