For make all, a build creates 8 copies of libjvm.so. This seems excessive. Disk space may be cheap but it's not free and not unlimited as it is a physical thing.

new hotspot build system:

philli% find . -name libjvm.so
./linux-x86_64-normal-server-fastdebug/support/modules_libs/java.base/amd64/server/libjvm.so
./linux-x86_64-normal-server-fastdebug/support/modules_libs-stripped/java.base/amd64/server/libjvm.so
du -s .
./linux-x86_64-normal-server-fastdebug/images/jre/lib/amd64/server/libjvm.so
./linux-x86_64-normal-server-fastdebug/images/jdk-server/lib/amd64/server/libjvm.so
./linux-x86_64-normal-server-fastdebug/images/jdk/lib/amd64/server/libjvm.so
./linux-x86_64-normal-server-fastdebug/hotspot/dist/lib/amd64/server/libjvm.so
./linux-x86_64-normal-server-fastdebug/hotspot/variant-server/libjvm/libjvm.so
./linux-x86_64-normal-server-fastdebug/jdk/lib/amd64/server/libjvm.so
philli% du -s .
4320344 .

old:
philli% cd build
philli% ls
linux-x86_64-normal-server-fastdebug/
philli% du -s .
3987780 .
(also has 8 copies of libjvm.so)