ZFS

[Sam]

On Thu, 16 Sep 2004, Gary Corcoran wrote:

> Sam wrote:
>
>> On Thu, 16 Sep 2004, Jan Grant wrote:
>> 
>>> On Thu, 16 Sep 2004, Sam wrote:
>>> 
>>>> Let's suppose you generate an exabyte of storage per year.  Filling a 
>>>> 64-bit
>>>> filesystem would take you approximately 8 million years.
>>> 
>>> 
>>> Hang on, I'm not sure I know where these numbers are coming from.
>>> 
>>> 1PB is - what? 2^50 bytes? That looks closer to 2^64 than your
>>> figures indicate. I'd imagine an exabyte a year ought to be topping out
>>> after 16 years. I'm missing about half-a-dozen orders of magnitude
>>> somewhere it seems.
>> 
>> 
>> 1PB is indeed 2^50 bytes, but filesystems don't address on the byte,
>> but on the block (1K, 4K, 8k, ...).  The numbers I'm using assume
>> the filesystem addresses on the sector, which is unrealistically
>> small.  Jack it up to a 16K blocksize and you jump a few hundred
>> ZB in size.
>
> You have to be able to *seek* on a byte boundary.  Hence doesn't a
> "64-bit" filesystem indeed mean "only" 2^64 bytes?

Only for the file you're seeking on.

Sam