Erased partitions, how to get back?

[nigratruo]

Hi,

I screwed up big time: I tried to install Windows 7 on another HD and got confused which disk I was dealing with. So instead of erasing partitions on the target disk for Windows 7, I destroyed the 2 (or 3) partitions of my Debian 9 install.
Now the two partitions got erased, but the data should still be there and intact. I used the standard Debian 9 install method, so that should be msdos partition type on a 1 TB disk and 2 or 3 partitions: LVM and encrypted and SWAP partition.
Now I have not touched the system yet, as I'm not sure how to proceed here. One idea I had was to "reinstall" Debian 9, but just do the partitioning and do not format anything, as it should partition it exactly the same as I did when I set up the system originally. Luckily, this was not so long ago, so no upgrade or anything happened, it was a fresh install.

Now messing around with the partition tables (creating new ones) should not erase any data on the partitions itself, right?
But the encryption (full system encryption) should make it a little more difficult. I currently don't have enough space to pull a full image with dd_rescue or such and will have to operate on the real disk. But I'm normally a very careful person that thinks first and then acts, so that makes the initial mistake (first one like this in many many years) much the dumber

Thanks,

Markus

[dilberts_left_nut]

Testdisk should be able to restore your partitions without much problem.
Your encrypted LVM might be more trouble though - I don’t know much about how that works so definitely do your own research before making any changes to your only cooy of the data - it could all become absolutely unrecoverable very easily.
You could, at a minimum, probably use dd to take a backup of the relevant partition header sectors etc. but again, verify what is the important bits of your encrypted partition.

[nigratruo]

Thanks for the tip, yeah, I myself am not that familiar how the different layers, LVM, LUCKS Filesystem affect restoring a partition table.