This disk is currently in use - it is not advisable to recreate partitions. Unmount all file systems and undo all the sharing partitions on this disk. use the --no-reread indicator to eliminate this check.
Is there much risks by commiting in live session??, I already did it, but i'd like to know for the next one.

sudo sfdisk /dev/sda < sda.ptbl --no-reread
failure to read the partition table again .: device or resource occupied the kernel still uses the old table. the new table will be used at the next restart or after you execute partprobe (8) or kpartx (8).
I executed partprobe to load the new table, and everything seems ok.