Gentoo Archives: gentoo-user

From: Robert Persson <ireneshusband@×××××.com>
To: gentoo-user@l.g.o
Subject: [gentoo-user] another mistakenly deleted partition to recover :(
Date: Thu, 28 Sep 2006 05:15:00
Message-Id: 1159420117.6029.52.camel@localhost
1 In the aftermath of my recent disaster in which I accidentally
2 reformatted my root partition I have been trying to install a new
3 system. Unfortunately this has led to some more partitions being
4 accidentally deleted and one of them had important data on it I need to
5 recover.
7 Unlike last time, this time the error was not mine. It was a fault
8 either in the Gentoo Linux Installer or in whichever utility it uses to
9 deal with partitions.
11 This is what happened.
13 I booted the live CD with evms enabled.
15 At the start there were two primary partitions on the disk in question,
16 followed by one extended one. The extended one in turn had four logical
17 partitions.
19 When I started the installer I went through all the screens and told it
20 what I wanted. When it came to partitioning I told it to delete the
21 first primary partition and replace it with one the same size, and to
22 delete the first logical partition and replace it with one the same size
23 also. This one was to be formatted reiserfs. I then saved my settings
24 before setting the installer to work.
26 It appeared from the messages that the installer had reformatted deleted
27 and replaced the first logical partition (although I don't know whether
28 it formatted it or not), but it borked when it came to the first primary
29 partition, saying that it was in use by the system. It wasn't mounted so
30 I suspected this might have had something to do with evms, but that
31 didn't make sense to me because both of the partitions in question had
32 entries in /dev/evms, but only one could be deleted and not the other. I
33 decided not to use evmsn to edit them and instead to try again with the
34 gentoo installer.
36 I started up the installer a second time (well, a fifth time actually)
37 and reloaded my settings from before. I was a bit puzzled when it came
38 to the partitioning screen because there was no easy way to tell whether
39 the partition diagram it displayed was how things actually were, or was
40 how things were supposed to be after various operations were carried
41 out. However I didn't want to spend all night choosing my use flags over
42 and over again each time the installer failed so I went ahead with the
43 settings from previously.
45 This time the installer complained that it couldn't have two partitions
46 in the same place, or something like that. I don't remember exactly. So
47 I started the installer again, reloaded my settings and found that the
48 three partitions after the logical partition I wanted replaced had now
49 all been deleted.
51 When I looked at the partition layout in parted I was surprised to find
52 that the logical partition I had wanted replaced was now larger than it
53 had been. It had been around 98GB or 99GB, but now it was 105GB. This
54 would be large enough to extend into the space occupied by the second
55 and third logical partition, but not the fourth, which was nonetheless
56 deleted too. parted listed no file system type for the remaining logical
57 partition, so I don't know whether it has been formatted (with reiserfs)
58 or not. I suppose I should have tried to mount it -ro to check, I can go
59 back and do that if it would be useful.
61 Anyway, the partition I now need to recover would be the third logical
62 partition (the one that the remaining logical partition just overlaps).
63 Am I right in thinking that if the remaining logical partition has in
64 fact been formatted, that the only changes that will have been made to
65 the disk will have been at the beginning of that partition, and that
66 therefore the data from the third partition ought to be intact?
68 Presumably then I simply need to find out where the beginning of that
69 partition would have been and to create another one of a sufficient size
70 starting in the same place (having deleted the first logical partition
71 of course). Is that right?
73 If so, how can I determine where the beginning would have been of that
74 deleted partition? It was, in its former life, an ext3 partition.
76 Many thanks
77 Robert
79 --
80 gentoo-user@g.o mailing list


Subject Author
Re: [gentoo-user] another mistakenly deleted partition to recover :( Wolfgang Illmeyer <wolfgang.illmeyer@×××.net>