Newfs /
newfs: construct a new file system
After you have used fdisk and disklabel to partition a disk, make sure to run newfs(8) in order to construct a new file system.
Suppose as mentioned in our previous examples, we used fdisk and set up the disklabel partition sd1a. We now use newfs(8):
$ doas newfs sd1a /dev/rsd1a: 524285.3MB in 1073736320 sectors of 512 bytes 644 cylinder groups of 814.44MB, 26062 blocks, 52224 inodes each super-block backups (for fsck -b #) at: ...
Now we can either mount the partition or add it permanently to /etc/fstab.