Kynn Jones a écrit : > > It turns out that I backed up the hard disk (HD) to the external drive > (XD) twice. The first backup went well, as far as I can tell. I > spot-checked individual files, etc. Everything looked normal. > > This first backup would have sufficed, but after I had done it I came > across the recommendation that a disk of that size (2TB) should be > formatted for ext4, whereas I had originally formatted it for ext2. I
Ext2 can handle 2 TB just fine. > reformatted the disk for ext4 (fdisk + mkfs.ext4), and then repeated > the backup. This backup procedure was in the form of a shell script, > that I had tested repeatedly. I just re-ran it. My memory is fuzzy > on the subsequent details. Since everything had gone so well up to > that point, I probably did not check everything as obsessively as I > had up to that point, but something must have gone very wrong. Before reading your next post, I also thought that the backup disk was not properly mounted after being reformatted. There should be some form of size limit or quota on /media to warn against this kind of common mistake. > At any rate, at the moment, my only hopes are that > > 1. something may be recoverable from the first backup in XD; > 2. something may be recoverable from HD. > > The second of these is (I think) less likely, because I changed the > partition scheme for HD, going from a single partition, to separate > partitions for /, /var, /tmp, and swap. In contrast, XD has always > consisted of a single partition. Yes, but not for this reason. Creating partitions does very little modification to a disk. IMO there are two better reasons : - There were much fewer overwrites to the XD (only filesystem metadata) than the HD (complete system installation). - Files on the XD were written in sequence and not modified, meaning that they are less fragmented and easier to recover. > Now I'm looking for some data recovery tool (preferably from Debian) > that either is part of some bootable media, or that I can use from a > USB stick after first booting from a Debian Live CD. I would have suggested photorec but you already found out.
