Today my startup disk was getting full and after searching found out Docker Beta is the culprit and was taking up more than 66GB. See output below.
You are able to reclaim diskspace resetting to factory defaults. Hopefully this can help someone with the same issues.
mark:~ mark$ ls -lh /Users/mark/.docker/machine/machines/default/disk.vmdk -rw------- 1 mark staff 9.7G May 19 10:08 /Users/mark/.docker/machine/machines/default/disk.vmdk mark:~ mark$ ls -lh /Users/mark/Library/Containers/com.docker.docker/Data/com.docker.driver.amd64-linux/ total 38534304 -rw-r--r-- 1 mark staff 18G May 26 22:16 Docker.qcow2 -rw-r--r-- 1 mark staff 64K May 26 22:17 console-ring -rw-r--r-- 1 mark staff 0B May 18 21:26 lock drwxr-xr-x 10 mark staff 340B May 26 21:08 log -rw-r--r-- 1 mark staff 17B May 25 22:18 mac.0 -rw-r--r-- 1 mark staff 36B May 18 21:26 nic1.uuid -rw-r--r-- 1 mark staff 5B May 25 22:18 pid lrwxr-xr-x 1 mark staff 12B May 25 22:18 tty -> /dev/ttys000 mark:~ mark$ ls -lh /Users/mark/Library/Containers/com.docker.docker/Data/com.docker.driver.amd64-linux/log/ total 90098344 -rw-r--r-- 1 mark staff 20M May 26 21:43 acpid.log -rw-r--r-- 1 mark staff 9.0G May 26 21:48 dmesg -rw------- 1 mark staff 26G May 26 22:03 docker.log -rw-r--r-- 1 mark staff 2.7K May 26 22:16 messages -rw-r--r-- 1 mark staff 400K May 26 21:26 messages.0 -rw-r--r-- 1 mark staff 2.8M May 26 21:26 proxy-vsockd.log -rw-r--r-- 1 mark staff 8.3G May 26 21:29 vsudd.log -rw-r--r-- 1 mark staff 0B May 18 21:26 wtmp