sadly I have a server and its backup but I cannot retrieve restic password. Do I have a chance to retrieve data?
I wouldn’t expect to be able to recover it easily or at all.
If you know what type of password you used you can of course try to brute force it even though it will take a lot of time and resources. This is only relevant/useful if you know that you e.g. started it with a capital character, ended it with a digit and that it’s just small chars in between and a few of them, etc. If you don’t know much about the password, consider it lost.
Filippo Valsorda once made an analysis of the encryption in restic that you can find here. Besides that there’s the design document in case that’s of any use. I’m mentioning these in case they can help give you some idea of how feasible or futile various attempts at guessing your password can be.
Do you not have the data available elsewhere?
Thank you for answer I reinstalled the machine without backup. I synced my data from PC. I lost only a little part of data.
Okay, that’s great news considering the situation!