# mkfs -t ext4 /dev/sdd1 mke2fs 1.42.8 (20-Jun-2013) /dev/sdd1 is apparently in use by the system; will not make a filesystem here!
This is a new disk to the new server. It is not mounted.
What’s wrong here? How to fix it?
This is possibly caused by a RAID signature on the disk showing that the disk belongs to a RAID.
If you are sure that the disk will never be used in a RAID system anymore, you may follow this tutorials to clean the RAID signature: How to Clean RAID Signatures on Linux
This issue can also be caused by multipath, if it is installed and in use. The device will need to included in multipath’s blacklist. (tip from Marcus White)