Re: [Ext2-devel] [RFC 0/13] extents and 48bit ext3

Jeff Garzik
2006-06-20T08:30:51Z

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 "partitioning is obsolete" ;-)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