(odyssey:20:50:EST)% dd if=/dev/urandom of=foo1.bin bs=1M count=10240
10240+0 records in
10240+0 records out
10737418240 bytes transferred in 10.204343 secs (1052240035 bytes/sec)
(odyssey:20:50:EST)% ls -lh foo1.bin 
-rw-r--r-- 1 prox staff 10G Dec 28 20:50 foo1.bin
(odyssey:20:50:EST)% df -h .
Filesystem     Size   Used  Avail Capacity iused      ifree %iused  Mounted on
/dev/disk3s5  228Gi   48Gi  166Gi    23% 1025114 1741771200    0%   /System/Volumes/Data
(odyssey:20:50:EST)% cp -c foo1.bin foo2.bin
(odyssey:20:50:EST)% du -h foo?.bin
 10G	foo1.bin
 10G	foo2.bin
(odyssey:20:50:EST)% cp -c foo1.bin foo3.bin                         
(odyssey:20:50:EST)% cp -c foo1.bin foo4.bin
(odyssey:20:50:EST)% cp -c foo1.bin foo5.bin
(odyssey:20:50:EST)% df -h .
Filesystem     Size   Used  Avail Capacity iused      ifree %iused  Mounted on
/dev/disk3s5  228Gi   48Gi  166Gi    23% 1025118 1741843000    0%   /System/Volumes/Data
(odyssey:20:51:EST)% du -h foo*
 10G	foo1.bin
 10G	foo2.bin
 10G	foo3.bin
 10G	foo4.bin
 10G	foo5.bin
(odyssey:20:51:EST)% dd if=/dev/zero bs=1 count=1 > foo5.bin
1+0 records in
1+0 records out
1 bytes transferred in 0.000180 secs (5556 bytes/sec)
(odyssey:20:52:EST)% df -h .
Filesystem     Size   Used  Avail Capacity iused      ifree %iused  Mounted on
/dev/disk3s5  228Gi   48Gi  166Gi    23% 1025119 1741842120    0%   /System/Volumes/Data
(odyssey:20:52:EST)%