I have a server that I think:
1. RAID stopped working looong time ago
2. I had to restart it but RAID failed and I believe the old hard drive mirrored itself to the one with the fresh data in one of my attempts to get the server running
3. Is there ANY way to retrieve that data?
This one looks quite grim, but still it's worth trying.
You may use R-Studio to do that. This article gives you an overall concept on how to work with RAIDs in R-Studio: RAID Recovery Presentation, this is R-Studio's on-line help, and if the file system of this RAID is NTFS/FAT, this free software will help you in finding RAID parameters ReclaiMe Free RAID Recovery.
R-Studio is a pay program but it allows you to estimate whether you can recover your files before buying it.
Do you think it will be less likely to recover the data since it may have gotten overwritten rather than deleted?