DF-3095 build log (guest, root)
$ cc -O -o tid_craft tid_craft.c -I/usr/src/sys/vfs/hammer
(no diagnostics, exit 0)  BUILD_OK
$ truncate -s 4G /root/base.img
$ vnconfig -c vn0 /root/base.img && newfs_hammer -f -L ua3095 /dev/vn0
newfs_hammer: Cannot create a HAMMER filesystem less than 10GB unless you use -f
Volume 0 DEVICE /dev/vn0        size   4.00GB
WARNING: The minimum UNDO/REDO FIFO is   0.50GB, you really should not
try to format a HAMMER filesystem this small.
WARNING: HAMMER filesystems less than 50GB are not recommended!
BASE_CREATED
$ ls -l tid_craft base.img
-rw-r--r-- 1 root wheel 4294967296 base.img
-rwxr-xr-x 1 root wheel     ... tid_craft