Even if two RAID disks go down, you have nothing to worry about. If you do not have any backup, be sure to use RAID Recovery software to recover data from a damaged RAID disk. Because after rebuilding a RAID 5 array, the data will be overwritten; i.e., it will disappear forever.

Can you rebuild RAID without losing data?

RAID comprises hard drives that are vulnerable to failure. ... And when this happens, rebuilding the RAID array is a viable solution to restore the data in failed drives. However, RAID rebuild is also not a fail-proof solution. The process of rebuilding an array is quite complex and needs expertise to avoid data loss.

Will creating a RAID array erase data?

The drive will need to be formatted in order to create a RAID array. So simple answer is yes, it will wipe the drive. Back up all your data that you need to a separate disc, create the RAID array, and put your data back.