JFS is a full 64-bit file system. All of the appropriate file system structure fields are 64-bits in size. This allows JFS to support both large files and partitions.

File system size
The minimum file system size supported by JFS is 16 Mbytes. The maximum file system size is a function of the file system block size and the maximum number of blocks supported by the file system meta-data structures. JFS will support a maximum file size of 512 terabytes (with block size 512 bytes) to 4 petabytes (with block size 4 Kbytes).

File size
The maximum file size is the largest file size that virtual file system framework supports. For example, if the frame work only supports 32-bits, then this limits the file size.