[CentOS] 32-bit kernel+XFS+16.xTB filesystem = potential disaster (was:Re: ZFS @ centOS)

[Warren Young]

On 4/5/2011 11:21 AM, Lamar Owen wrote:
>> Dropping to 16.37 TB on the RAID configuration by switching to
>> RAID-6 let us put almost the entire array under a single 16 TB XFS
>> filesystem.
>
> You really, really, really don't want to do this.

Actually, it seems that you can't do it any more.  I tried, just to see 
what would happen.  (I already knew about all you're talking about.) 
You are still able to convince gparted to create a > 16 TB partition on 
32-bit CentOS 5, but when you go to format it, it gives some bogus error 
that doesn't tell you what actually went wrong.  Repartition to get 
under 16 TB, and the mkfs step succeeds.

I expect they added some checks for this since you last tried XFS on 32-bit.

Perhaps it wasn't clear from what I wrote, but the big partition on this 
system is actually 15.9mumble TB, just to be sure we don't even get 1 
byte over the limit.  The remaining 1/3 TB is currently unused.