The Wizards note that you did not check the OpenVMS Frequently Asked Questions
list for your question. The following is an excerpt from the FAQ:
FILE5. What is the largest disk volume size OpenVMS can access?
One Terabyte (2**31 blocks of 2**9 bytes). Prior to the release of V6.0, the
OpenVMS file system was limited to disk volumes of 8.5 GB (2**24 blocks) or
On some systems, there are restrictions in the console program that limit the
size of the OpenVMS system disk. Note that data disks are not affected by
console program limits. For example, all members of the VAXstation 3100
series are limited to a system disk to 1.073 GB or less due to the console,
though larger data disks are possible.