Java on Linux x86-64 supports 48-bit pointers and 256 TB of virtual address space, of which 128 terabytes is reserved for the Kernel , and 128 terabytes for User space.    Maximum Heap in  t heory on WAS Linux x86-64 would be -Xmx128t  with the caveat or requirement of having   -Xnocompressedrefs in place also, which essentially means Disabling Compressed References . Maximum Heap in practice on WAS Linux x86-64 would be approximately -Xmx76t for Java heap because the rest, or 52 TB, is used by Native heap .  *There is no Java heap size... [More]

Tags:  ibm-blog 64 largest linux bit xcompressedrefs xnocompressedrefs xmx 32 heap java maximum