On 2011-06-22, at 10:11 PM, Charles Taylor wrote: > Normally I would not be coming here for help, but I made a big mistake > and frankly don't think any other group has sufficient kernel/ext4 > knowledge to help me. > > My partition table used to look like this: > > /dev/sda1 start:6144 end:10743 > /dev/sda2 start:10743 end:10946 > > I deleted /dev/sda1 on a live system and recreated it like so: > > /dev/sda1 start:1 end:10742 > > And rebooted. > > Please don't ask why I did that, or how it happened. It is a long > story and was an accident. > > Needless to say, it really messed things up. I booted a rescue disk > and changed the table back to this: > > /dev/sda1 start:6144 end:10742 > /dev/sda2 start:10743 end:10946 > > Rebooted. No luck. > > fsck.ext4 can't find a valid superblock and I haven't had any luck > finding a backup. Some things that may help: On another system, download the e2fsprogs code and compile the "findsuper" tool in the misc/ directory. If you run this against the /dev/sda device it will print out all of the ext[23] superblocks that it finds on disk (checking every 512-byte sector offset) and prints out what it thinks are the offset+size of the partitions that those filesystems lived on. > * MBR partition table. > * All changes made with fdisk. > * I found what looks like it may be a superblock at cylinder 6144, > head 4, sector 16, with an offline disk editor but don't know how to > tell fsck to use it. Note that newer fdisk might create different layouts than older versions, depending on what options/geometry are used. It might make more sense to just use sector addresses instead of CHS, since this would be far easier to align to the output of findsuper anyway. > * Block size is 512 bytes. > * Disk is a 90GB SSD. > > So, anyone know how I can return this file system to working order? If it is an SSD, it's possible that repartitioning it wiped the data. Some SSDs do strange things like this in order to keep their garbage collection under control. Cheers, Andreas -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
