From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jeff Garzik <jeff@garzik.org>
Subject: Re: [Ext2-devel] [RFC 0/13] extents and 48bit ext3
Date: Tue, 20 Jun 2006 04:30:40 -0400
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Cc: Qi Yong <qiyong@fc-cn.com>, Linus Torvalds <torvalds@osdl.org>,
	Andrew Morton <akpm@osdl.org>,
	"Stephen C. Tweedie" <sct@redhat.com>,
	"ext2-devel@lists.sourceforge.net" <ext2-devel@lists.sourceforge.net>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	Mingming Cao <cmm@us.ibm.com>, linux-fsdevel@vger.kernel.org,
	alex@clusterfs.com, Andreas Dilger <adilger@clusterfs.com>
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To: Laurent Vivier <Laurent.Vivier@bull.net>
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Laurent Vivier wrote:
> Qi Yong wrote:
>> Linus Torvalds wrote:
>>
>>> On Fri, 9 Jun 2006, Stephen C. Tweedie wrote:
>>>  
>>>
>>>> When is the Linux syscall interface enough?  When should we just bump it
>>>> and cut out all the compatibility interfaces?
>>>>
>>>> No, we don't; we let people configure certain obsolete bits out (a.out
>>>> support etc), but we keep it in the tree despite the indirection cost to
>>>> maintain multiple interfaces etc.
>>>>    
>>>>
>>> Right. WE ADD NEW SYSTEM CALLS. WE DO NOT EXTEND THE OLD ONES IN WAYS THAT 
>>> MIGHT BREAK OLD USERS.
>>>
>>> Your point was exactly what?
>>>
>>> Btw, where did that 2TB limit number come from? Afaik, it should be 16TB 
>>> for a 4kB filesystem, no?
>>>  
>>>
>> Partition tables describe partitions in units of one sector.
>> 2^(32+9) = 2T
>>
>> To prevent integer overflow, we should use only 31 bits of a 32-bit integer.
>> 2^(31+12) = 8T
>>
>> There's _terrible_ hacks to really get to 16T.
>>
>> -- qiyong
>>
> 
> IMHO, a simple solution is to use "Logical Volume Manager" instead of partition
> manager: we create 64bit filesystem in a Logical Volume, not in a partition.

That doesn't solve anything, if you are not using a 64bit filesystem.


> "partitioning is obsolete" ;-)

LVM is nothing but a partition manager...

	Jeff