"T", Tera-, is the standard SI prefix for 1012. There is no disc size limit at the 2,000,000,000,000 byte mark.
The only disc size limits anywhere near the 2TB mark are the two 2TiB disc size limits on MBR style partition tables and on bootable disc volumes formatted as FAT, NTFS, HPFS or any other filesystem type that has a BIOS parameter block. But those limits are at 2 terabinarybytes, which is 199,023,255,552 bytes — just over 185 gigabinarybytes — above the 2 terabyte mark. Calling those limits "2TB" limits is to make an error that is larger than the entireties of some current hard discs.
2 terabytes isn't even an integer multiple of 512 bytes, and so doesn't represent a whole number of disc sectors. It's impossible for a disc size limit to even exist at the 2TB mark.