Re: Distributed storage. Move away from char device ioctls.

J. Bruce Fields
2007-09-14T22:42:32Z

On Fri, Sep 14, 2007 at 06:32:11PM -0400, Jeff Garzik wrote:
> J. Bruce Fields wrote:
>> On Fri, Sep 14, 2007 at 05:14:53PM -0400, Jeff Garzik wrote:
>>> J. Bruce Fields wrote:
>>>> On Fri, Sep 14, 2007 at 03:07:46PM -0400, Jeff Garzik wrote:
>>>>> I've been waiting for years for a smart person to come along and write
>>>>> a POSIX-only distributed filesystem.
>>>> What exactly do you mean by "POSIX-only"?
>>> Don't bother supporting attributes, file modes, and other details not
>>> supported by POSIX. The prime example being NFSv4, which is larded down
>>> with Windows features.
>> I am sympathetic.... Cutting those out may still leave you with
>> something pretty complicated, though.
>
> Far less complicated than NFSv4.1 though (which is easy :))

One would hope so.

>>> NFSv4.1 adds to the fun, by throwing interoperability completely out the
>>> window.
>> What parts are you worried about in particular?
>
> I'm not worried; I'm stating facts as they exist today (draft 13):
>
> NFS v4.1 does something completely without precedent in the history of NFS:
> the specification is defined such that interoperability is -impossible- to
> guarantee.
>
> pNFS permits private and unspecified layout types. This means it is
> impossible to guarantee that one NFSv4.1 implementation will be able to
> talk another NFSv4.1 implementation.

No, servers are required to support ordinary nfs operations to the
metadata server.

At least, that's the way it was last I heard, which was a while ago. I
agree that it'd stink (for any number of reasons) if you ever *had* to
get a layout to access some file.

Was that your main concern?

--b.