I need a little help from a GRUB expert.
I just cloned a 1 TB Seagate drive onto a brand new 2 TB Hitachi, and before swapping them out, I decided to boot-test it. It's tied to my computer through a SATA 2 to USB adapter. The 25-hour cloning operation seems to have worked fine; I used dd piped through pv.
However, when I boot, I now get a message from GRUB2 saying that the partition is not found; then get dumped to the grub rescue prompt.
ls gives me a one-partition drive on hd0 (not sure what this is, possibly a thumb drive), a sequence of partitions on hd1, and a single-partition on hd2 (again, no idea what this is). (hd1,msdos10) seems to be a non-bootable partition that I keep around; most of the others (those on an ext file system) are recognized. I find my Ubuntu Trusty Tahr root on (hd1,msdos5). However, even after "set root=(hd1,msdos5)", all attempts at insmod ("insmod normal") and ("insmod linux") return "Partition not found".
I'm guessing that the MBR of my new drive is not relevant to the partitions cloned onto it. What I'm not sure of is how to fix that. Again, the target drive is mounted externally (even though it's ultimately an internal drive); and I can boot to a LiveUSB or hda, but not it. It has a Windows 7 partition, Ubuntu 14.04, and a sequence of additional partitions inclusive of Windows Recovery/Repair/Whatever-They're-Calling-It, my extra partition at the end, my home partition, swap, and probably one or two other guys like temp.
In the worst case, I suppose I could reinstall all of Ubuntu 14.04, but that would require a lot of further time prying through the repos to get all my old stuff back. I'm sure this is simple, but the MBR is not the kind of thing I screw around with unless absolutely necessary, especially when I don't know what I'm doing and it's a potential 25-hour fix!
Quoted terminal output from GRUB:
ls > (hd0) (hd0,msdos3) (hd0,msdos2) (hd0,msdos1) (hd1) (hd1,msdos11) (hd1,msdos10) (hd1,msdos9) (hd1,msdos8) (hd1,msdos7) (hd1,msdos6) (hd1,msdos5) (hd1,msdos3) (hd1,msdos2) (hd1,msdos1) (hd2) (hd2,msdos1) ls (hd0,1) > Filesystem is unknown ls (hd0,msdos1) > Filesystem is unknown set root=(hd1,msdos5) insmod normal > Partition not found ...