Although the 64-bit offset format allows the creation of much larger netCDF files than was possible with the classic format, there are still some restrictions on the size of variables.
It's important to note that without Large File Support (LFS) in the operating system, it's impossible to create any file larger than 2 GiBytes. Assuming an operating system with LFS, the following restrictions apply to the netCDF 64-bit offset format.
No fixed-size variable can require more than 2^32 - 4 bytes (i.e. 4GiB
A 64-bit offset format netCDF file can have up to 2^32 - 1 fixed sized variables, each under 4GiB in size. If there are no record variables in the file the last fixed variable can be any size.
No record variable can require more than 2^32 - 4 bytes of storage for each record's worth of data, unless it is the last record variable. A 64-bit offset format netCDF file can have up to 2^32 - 1 records, of up to 2^32 - 1 variables, as long as the size of one record's data for each record variable except the last is less than 4 GiB - 4.
Note also that all netCDF variables and records are padded to 4 byte boundaries.