I need to increase the partition using the empty space located before the partition starts without data loss. As far as I know to resize the partition and to leave data intact one should start the new partition from the same disk sector as before. Is it possible to find a solution in this case using fdisk? Moreover the partition has a filesystem. Will the resizing with fdisk damage filesystem and data?
Do you need to make the partition larger or smaller?
Maybe this helps: https://geekpeek.net/resize-filesystem-fdisk-resize2fs/
Any method would suggest that you back up the data anyway. Thus, backing up the data, changing the size, and restoring is a likely course of action.
There are toolsets like PartedMagic that contain tools like clonezilla and other formatting, partitioning, sizing, and such.