I was having ubuntu 10.04 on my system, and 2 partitions one with 80 GB and the Other with 70 Gb. I took a backup from 80 GB partition and saved it in 70 GB, I installed Ubuntu 11.04 on my system, when i loged in I found there is only one partition of 160GB size, I guess I have formated both the partitions and they are merged now, tried to look the size and found only 18 MBs Of Data. I was having very important data in it, Please help me out how can i recover it. Is there any way i can do that?
Your data is most likely not recoverable. You could try to boot from another drive and try to use a utility like TestDisk on it but it is far more likely that you won't be able to get anything back without Backups