GPT/Protective MBR problem...

ETC Boot Loaders
1

Hi,

short thing: I've done something I didn't know what happens; bad thing: I did it with my partition table. :smiley:

My OS is Ubuntu 10.10. I've used GPT and now want to convert it to MBR with gdisk.
I started gdisk, chose 'r' for "transformation options" and chose 'g' to "convert GPT into MBR and exit".
Then I rebooted. Now all my programs tell me something other:

fdisk says the following (language is german):

   Ger�t  boot.     Anfang        Ende     Bl�cke   Id  System
/dev/sda1               1      121602   976762583+  ee  GPT

gdisk says it to be a protective MBR, but '-l' switch doesn't print any partition:

GPT fdisk (gdisk) version 0.5.1

Partition table scan:
  MBR: protective
  BSD: not present
  APM: not present
  GPT: present

Found valid GPT with protective MBR; using GPT.

The kernel doesn't seem to detect anything, only sda* thing is /dev/sda.

partitionmanager says that there is no valid partition table.

Now, what should I do? Stupid thing is that I missed to make a backup of my first sectors before. :frowning:
Remember, the only thing I want is to be able to read my partitions on sda again and to have an MBR on it in the end.

Blackbird

2

Humm, the conversion from GPT to MBR by gdisk is a best-faith attempt only according to the man page. No guarantees, especially if there were no free blocks between the partitions.

You could try the -c option to load the backup partition table but I suspect that it will contain nothing.

3

Oh dear. :frowning: Lucky me that a made a backup of my data before.

I think I will just create a new MBR and restore my backups...

4

Yes, that is the best plan. Glad you had a backup. It is my opinion that utilities such as gdisk should not attempt to automatically convert from MBR to GPT and visa versa. Too many edge cases where things can go wrong.