128TB filesystem limit?

[david at lang.hm]

I'm working with a raid 0 (md) array on top of 10 16x1TB raid 6 hardware 
arrays.

fdisk -l shows me 10 drives like

WARNING: GPT (GUID Partition Table) detected on '/dev/sdk'! The util fdisk 
doesn't support GPT. Use GNU Parted.


Disk /dev/sdk: 13999.9 GB, 13999999025152 bytes
255 heads, 63 sectors/track, 1702069 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x00000000

    Device Boot      Start         End      Blocks   Id  System
/dev/sdk1               1      267350  2147483647+  ee  EFI GPT

and then the md0 device as

Disk /dev/md0: 139999.9 GB, 139999989596160 bytes
2 heads, 4 sectors/track, -1 cylinders
Units = cylinders of 8 * 512 = 4096 bytes
Disk identifier: 0x00000000

Disk /dev/md0 doesn't contain a valid partition table


I then did mkfs.xfs /dev/md0

but a df is showing me 128TB

is this just rounding error combined with the 1000=1k vs 1024=1k marketing 
stuff, or is there some limit I am bumping into here.

David Lang