Is it possible to create a raid1 of 2 disks if one has data without losing it?

Question

linux

there is linux mint
dev/sda 240GB system
dev/sdb 1Tb data
dev/sdc 1Tb empty
is it possible to mirror (raid 1) sdc to sdb without losing data on sdb

Answer 1

The array can be created in a degraded form:
mdadm -C /dev/md0 -l 1 -n 2 missing /dev/sdc
Then copy the data to the array
rsync sdb -> md0
And add the disk to the array
mdadm /dev/md0 -a /dev/ sdb