  While the retag would be the route I would look into, I am not sure if the other drives changed the structure of the VD yet. If you are certain that the data is copied and protected, we can try with the original drives to see if we can recover it to then retry the expansion. Again this is going to risk the data, so I wanted to let you know.Retagging is the process of deleting the Virtual Disk, and then recreating it exactly as it was (raid level, stripe size, etc), but without initializing the virtual disk, as initializing would format the drives deleting the data.  So essentially you would delete it, recreate it with the original drives without initializing the VD, boot to OS and verify data, then retry the expansion with the other drives. Now you may likely need to format the new expansion drives, to clear the VD flags from it before trying to expand.   
Dear Dell Community, I'm currently facing an issue with my RAID 5 array on an R7515 server with a PERC H730P Mini RAID controller. I'd like to share the details of my problem and seek assistance from the community. Initially, I had a RAID 5 array consisting of three 14TB disks. To expand the storage, I inserted two new disks of the same type, and the RAID controller started the reconstruction process. During the reconstruction, which reached around 23% progress after 2 days, a power outage occurred. I gracefully shut down the machine before the UPS ran out of power. Unfortunately, the hydro repair took longer than expected, and the server eventually lost power completely. Upon restarting the server, the RAID controller recognized all five disks as having a foreign RAID configuration. When trying to import this configuration, it displayed an error stating that "the configuration is not complete." The disks themselves are relatively new and working normally. I've tried various troubleshooting steps, including using the perccli tool to analyze the RAID configurations. Interestingly, the perccli tool shows that the two newly inserted disks have a RAID 5 mark and the original 25.465TB size, but the initial three disks are recognized as standalone disks without any RAID mark. Perccli also reported that there are no dirty data in the cache. All disks have remained in their original position and have not been moved or touched ever since. I'm wondering if there's any way to recover the RAID array and the valuable data stored on it. I'd appreciate any suggestions, guidance, or insights on this issue from the community. Thank you in advance for your assistance.
RAID 5 array shown as foreign during expansion rebuild