Re: [LSF/MM TOPIC][ATTEND] linux servers as a storage server - what's missing?

[Chuck Lever <chuck.lever@oracle.com>]

On Jan 17, 2012, at 4:16 PM, J. Bruce Fields wrote:

> On Tue, Jan 03, 2012 at 02:32:40PM -0500, Chuck Lever wrote:
>> 
>> On Jan 3, 2012, at 2:26 PM, Jeff Layton wrote:
>> 
>>> On Wed, 21 Dec 2011 10:59:43 -0500
>>> Ric Wheeler <rwheeler@redhat.com> wrote:
>>> 
>>>> 
>>>> One common thing that I see a lot of these days is an increasing number of 
>>>> platforms that are built on our stack as storage servers. Ranging from the 
>>>> common linux based storage/NAS devices up to various distributed systems.  
>>>> Almost all of them use our common stack - software RAID, LVM, XFS/ext4 and samba.
>>>> 
>>>> At last year's SNIA developers conference, it was clear that Microsoft is 
>>>> putting a lot of effort into enhancing windows 8 server as a storage server with 
>>>> both support for a pNFS server and of course SMB. I think that linux (+samba) is 
>>>> ahead of the windows based storage appliances today, but they are putting 
>>>> together a very aggressive list of features.
>>>> 
>>>> I think that it would be useful and interesting to take a slot at this year's 
>>>> LSF to see how we are doing in this space. How large do we need to scale for an 
>>>> appliance?  What kind of work is needed (support for the copy offload system 
>>>> call? better support for out of band notifications like those used in "thinly 
>>>> provisioned" SCSI devices? management API's? Ease of use CLI work? SMB2.2 support?).
>>>> 
>>>> The goal would be to see what technical gaps we have that need more active 
>>>> development in, not just a wish list :)
>>>> 
>>>> Ric
>>> 
>>> Unfortunately, w/o a wishlist of sorts, it's hard to know what needs
>>> more active development ;).
>>> 
>>> While HCH will probably disagree, being able to support more
>>> NFSv4/Windows API features at the VFS layer would make it a lot easier
>>> to do a more unified serving appliance. Right now, both knfsd and samba
>>> track too much info internally, and that makes it very difficult to
>>> serve the same data via multiple protocols.
>>> 
>>> Off the top of my head, my "wishlist" for better NFSv4 serving would be:
>>> 
>>> - RichACLs
>>> - Share/Deny mode support on open
>>> - mandatory locking that doesn't rely on weirdo file modes
>> 
>> To add a few more NFSv4 related items:
>> 
>> - Simplified ID mapping
> 
> What are you thinking of here?
> 
> --b.
> 
>>   and security configuration

Trond has already made things easier for NFSv3 to NFSv4 transition by having the client send numeric UIDs and GIDs in idmap strings when servers can deal with that.

It would be even better if we had some kind of GUI like the "Users and Groups" tool that could combine the configuration of ID mapping and security configuration, and maybe provide some nice preset configurations (all local IDs, Kerberos only, LDAP, and so on).

This also needs to integrate well with network services like FreeIPA.  And it would probably need to work on both both NFS clients and servers, but what if we had some way of automatically configuring clients, on first contact with a server or realm, with a Kerberos keytab and the correct ID mapping and security set up?

>> - Support for NFSv4 migration and replication
>> - Better server observability (for operational and performance debugging in the field)
>> - FedFS and NFS basic junctions (already under way)
>> 
>>> It's always going to be hard for us to compete with dedicated
>>> appliances. Where Linux can shine though is in allowing for more
>>> innovative combinations.
>>> 
>>> Being able to do active/active NFS serving from clustered filesystems,
>>> for instance is something that we can eventually attain but that would
>>> be harder to do in an appliance. This sort of discussion might also
>>> dovetail with Benny's proposal about pNFS serving.
>>> 
>>> -- 
>>> Jeff Layton <jlayton@redhat.com>
>>> --
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>> 
>> -- 
>> Chuck Lever
>> chuck[dot]lever[at]oracle[dot]com
>> 
>> 
>> 
>> 
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-- 
Chuck Lever
chuck[dot]lever[at]oracle[dot]com