how to know if some data already exist on device - disk
The simple way to check if disk include filesystem is to do:
mount /grid/sdb /mnt
and if sdb or other /dev/sdx have file-system then mount will be succeeded, if not ... probably file system exists!
but this is ugly way to check that..
what the other elegant alternative to check file-system on disk?
my target is to check if file-system already configured on disk's as /dev/sdb - /dev/sdx
blkid
/lsblk -f