In the aftermath of my recent disaster in which I accidentally reformatted my root partition I have been trying to install a new system. Unfortunately this has led to some more partitions being accidentally deleted and one of them had important data on it I need to recover.
Unlike last time, this time the error was not mine. It was a fault either in the Gentoo Linux Installer or in whichever utility it uses to deal with partitions. This is what happened. I booted the live CD with evms enabled. At the start there were two primary partitions on the disk in question, followed by one extended one. The extended one in turn had four logical partitions. When I started the installer I went through all the screens and told it what I wanted. When it came to partitioning I told it to delete the first primary partition and replace it with one the same size, and to delete the first logical partition and replace it with one the same size also. This one was to be formatted reiserfs. I then saved my settings before setting the installer to work. It appeared from the messages that the installer had reformatted deleted and replaced the first logical partition (although I don't know whether it formatted it or not), but it borked when it came to the first primary partition, saying that it was in use by the system. It wasn't mounted so I suspected this might have had something to do with evms, but that didn't make sense to me because both of the partitions in question had entries in /dev/evms, but only one could be deleted and not the other. I decided not to use evmsn to edit them and instead to try again with the gentoo installer. I started up the installer a second time (well, a fifth time actually) and reloaded my settings from before. I was a bit puzzled when it came to the partitioning screen because there was no easy way to tell whether the partition diagram it displayed was how things actually were, or was how things were supposed to be after various operations were carried out. However I didn't want to spend all night choosing my use flags over and over again each time the installer failed so I went ahead with the settings from previously. This time the installer complained that it couldn't have two partitions in the same place, or something like that. I don't remember exactly. So I started the installer again, reloaded my settings and found that the three partitions after the logical partition I wanted replaced had now all been deleted. When I looked at the partition layout in parted I was surprised to find that the logical partition I had wanted replaced was now larger than it had been. It had been around 98GB or 99GB, but now it was 105GB. This would be large enough to extend into the space occupied by the second and third logical partition, but not the fourth, which was nonetheless deleted too. parted listed no file system type for the remaining logical partition, so I don't know whether it has been formatted (with reiserfs) or not. I suppose I should have tried to mount it -ro to check, I can go back and do that if it would be useful. Anyway, the partition I now need to recover would be the third logical partition (the one that the remaining logical partition just overlaps). Am I right in thinking that if the remaining logical partition has in fact been formatted, that the only changes that will have been made to the disk will have been at the beginning of that partition, and that therefore the data from the third partition ought to be intact? Presumably then I simply need to find out where the beginning of that partition would have been and to create another one of a sufficient size starting in the same place (having deleted the first logical partition of course). Is that right? If so, how can I determine where the beginning would have been of that deleted partition? It was, in its former life, an ext3 partition. Many thanks Robert -- gentoo-user@gentoo.org mailing list
