The basic OT release (tarball) takes up about 100 MB of disk space, but is significantly larger (
200 MB) if Java is included. If the new installer is downloaded the required space is closer to 300 MB.
The default memory allocation for the OT is 4 GB, but this can be changed using the OT Installer. This large amount of memory means that only 64-bit versions of Java can be used with the OT.