NFS ACL compatibility [was: Re: [2.6] The List, pass #2]

NFS ACL compatibility [was: Re: [2.6] The List, pass #2]

[Mikael Pettersson]

On Thu, 1 Aug 2002 10:34:23 +1000 (EST), Neil Brown wrote: 
>Well, given that the protocol specification isn't 100% finalised, it's
>not clear that pushing for inclusion now is entirely sensible.  We
>don't want people to be using an NFSv4 on Linux that is incompatible
>in some subtle way with other vendors.
>
>Also, I suspect that NFSv4 will be fairly localised in the changes it
>makes and could well go in to 2.6.10 of whatever (afterall, reiserfs
>went in at 2.4.2).
>
>There are some changes that NFSv4 would like to make that affect
>common code, such as making open(,O_EXCL) work for a networked
>filesystem, but we can live without that (as we do with NFSv3), but
>hopefully that functionality will get in before halloween anyway. 

Speaking of NFS compatibility: can Linux' NFS server implement ACLs
in a way that's compatible with Solaris NFS clients?

A sysadmin over here says this isn't the case, because Sun apparently
stepped outside of the NFSv3 protocol and handles ACLs with a
separate RPC program.

The significance of this is that unless Linux' NFS server can be made
fully compatible with Solaris NFS clients, we can't use Linux for the
new high-performance NFS servers we need to install this fall, forcing
us to go with Solaris and fairly expensive Sun HW.

/Mikael

Re: NFS ACL compatibility [was: Re: [2.6] The List, pass #2]

[Neil Brown]

On Thursday August 1, mikpe@csd.uu.se wrote:
> 
> Speaking of NFS compatibility: can Linux' NFS server implement ACLs
> in a way that's compatible with Solaris NFS clients?

Can?  well, anything is possible.  It's just an SMP - a simple matter
      of programming.
Does? no.  Linux doesn't even support ACLs (without patches)  I know
      of no work to interface any of the ACL patches with NFS, except
      for the NFSv4 work, which doesn't really help you.

> 
> A sysadmin over here says this isn't the case, because Sun apparently
> stepped outside of the NFSv3 protocol and handles ACLs with a
> separate RPC program.

Yep.  NFSv3 doesn't know about ACLs. SUN invented an NFS_ACL protocol
which is sufficiently well documented (I have a .x file) that it would
be fairly trivial to implement ... if you had a filesystem that could
store compatible acls.

> 
> The significance of this is that unless Linux' NFS server can be made
> fully compatible with Solaris NFS clients, we can't use Linux for the
> new high-performance NFS servers we need to install this fall, forcing
> us to go with Solaris and fairly expensive Sun HW.

So the question becomes,  does the price difference mean enough money
that it is worth contracting someone to make it work.... and can you
afford the risks.

NeilBrown