Quoting Kevin O'Gorman (kogor...@gmail.com): > I'm working with new 4TB drives, and one of them just had a bad spot in a > fairly awkward place. > The very first block of an ext4 partition was unreadable, and caused problems > in booting, as well as anything else that wanted to scan partitions. > > I overwrote the first 4K with zeroes, deleted the partition (with gdisk) and > created a new unformatted partition to cover the area. Now that partition > passes a read test, and I'm checking the other partitions. > > The damaged partition has been inactive for a while, so I'm quite sure I have > adequate backups. But now seems to be a time for me to learn -- lots of > things > have been going wrong, and I've been learning how to cope. > > So I wonder if there's a way to get that partition back, at least in part, > without using my backups.
Having had a similar problem where the first few blocks of a partition wouldn't read, I used dd to ascertain what I could and couldn't read, and then: Create a blank start of a file: dd bs=512 if=/dev/zero of=/ylarge/image-of-hdd4-skipping-16 count=16 Add the undamaged part of the partition: dd bs=512 if=/dev/hdd4 of=/ylarge/image-of-hdd4-skipping-16 skip=16 seek=16 See if it can be mended: e2fsck -n -f /ylarge/image-of-hdd4-skipping-16 If so, mend it: e2fsck -f /ylarge/image-of-hdd4-skipping-16 Mount it: mount -t ext3 -o ro,loop=/dev/loop0 /ylarge/image-of-hdd4-skipping-16 /mnt Copy off all the files. hdd4 was the failed partition. /ylarge was a filesystem big enough to hold an image of hdd4. Note however that hdd4 was ext3, not ext4. I don't know whether that affects things. Good luck. Cheers, David. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: https://lists.debian.org/20150122045521.ga17...@alum.home