On 25/10/16 12:33, Matt Price via talk wrote:
OK, so I did this
dd if=some.iso of=/dev/sdb
oops -- that's not the USB key! that's my internal m.2 drive!
The partition table is gone, but it used to contain 2 partitions, both of them in an LVM, one of them part of an extended logical volume that added space to /home on my overburdened main drive. I haven't lost much data (just the first 700mb were overwritten), and amazingly my laptop continues to run just fine -- even though lvscan reports a missing drive, apparently the data is still findable.
I'd like to restore the partition table but I don't know where the partition boundaries are, and in any case I don't know how to write a partition table (!). What tools should I use? Preferably without turning off my laptop, since I'm afraid it won't boot back up again!
Apart from the data loss, right now you're in a good position to recover things. First, make a copy of /proc/partitions for reference in case you need to restore from it. You have a few options: 1. Restore LVM since you're using that: https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/htm... Those backups have saved me on multiple occasions. 2. testdisk is a great tool for these kinds of problems. Download and run it from /dev/shm. It may not find the deleted partitions or see in memory stuff, but it won't hurt to try. 3. Use your /proc/partitions as a reference, since it has a list of the partitions from before the dd operation. With it you could reconstruct a partition table if the LVM restore steps don't work. http://prefetch.net/blog/index.php/2009/12/20/using-the-linux-parted-utility... for more on that approach. Good luck!