128TB filesystem limit?

[Dave Chinner]

On Thu, Mar 25, 2010 at 04:15:42PM -0700, david at lang.hm wrote:
> 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

What is in /proc/partitions?

> is this just rounding error combined with the 1000=1k vs 1024=1k
> marketing stuff,

Probably.

> or is there some limit I am bumping into here.

Unlikely to be an XFS limit - I was doing some "what happens if"
testing on multi-PB sized XFS filesystems hosted on sparse files
a couple of days ago....

Cheers,

Dave.
-- 
Dave Chinner
david at fromorbit.com