Linux client access to NFSv4 Alternate Data Streams (O_XATTR)?

Linux client access to NFSv4 Alternate Data Streams (O_XATTR)?

[Joshuah Hurst]

We need to access NFSv4 Alternate Data Streams (what Solaris,
NexentaOS, Omnios and SmartOS can openat() with the O_XATTR flag) from
a (Suse) Linux client.

OS is Suse Linux 12.3, x86-64, 64bit

Does anyone know how to archive this?

Josh

Re: Linux client access to NFSv4 Alternate Data Streams (O_XATTR)?

[Trond Myklebust]

On Dec 2, 2013, at 7:13, Joshuah Hurst <joshhurst@gmail.com> wrote:

> We need to access NFSv4 Alternate Data Streams (what Solaris,
> NexentaOS, Omnios and SmartOS can openat() with the O_XATTR flag) from
> a (Suse) Linux client.
> 
> OS is Suse Linux 12.3, x86-64, 64bit
> 
> Does anyone know how to archive this?

Why can’t you access Solaris-specific extensions from a Solaris client?

Trond

Re: Linux client access to NFSv4 Alternate Data Streams (O_XATTR)?

[Sebastian Feld]

On Mon, Dec 2, 2013 at 2:29 PM, Trond Myklebust
<trond.myklebust@primarydata.com> wrote:
>
> On Dec 2, 2013, at 7:13, Joshuah Hurst <joshhurst@gmail.com> wrote:
>
>> We need to access NFSv4 Alternate Data Streams (what Solaris,
>> NexentaOS, Omnios and SmartOS can openat() with the O_XATTR flag) from
>> a (Suse) Linux client.
>>
>> OS is Suse Linux 12.3, x86-64, 64bit
>>
>> Does anyone know how to archive this?
>
> Why can’t you access Solaris-specific extensions from a Solaris client?

This isn't a Solaris-specific extension, its part of the original Sun
NFSv4 spec. Unfortunately the ARC/ARchitecture Cases from
Opensolaris.org are no longer available, otherwise the background,
e.g. feature parity with CIFS/NTFS, and the overall usefulness of such
a feature, would be clearer.

There are many many applications coming from either the Windows world
or the HPC camp (like nih.org or GE Healthcare) who mandatory rely on
the existence of this feature (well, at least enough so that AT&T
cloud services and the related toolchain (e.g. AST, including ksh93)
now have extensive support for O_XATTR).

Sebastian

Re: Linux client access to NFSv4 Alternate Data Streams (O_XATTR)?

[Christoph Hellwig]

On Mon, Dec 02, 2013 at 03:27:20PM +0100, Sebastian Feld wrote:
> This isn't a Solaris-specific extension, its part of the original Sun
> NFSv4 spec. Unfortunately the ARC/ARchitecture Cases from
> Opensolaris.org are no longer available, otherwise the background,
> e.g. feature parity with CIFS/NTFS, and the overall usefulness of such
> a feature, would be clearer.

It's a dumb part of the spec, and Linux has no intent support pretty
braindead file/directory mixups.  Just store all your separate streams
in separate files, that's how it's implemented underneath anyway.

Re: Linux client access to NFSv4 Alternate Data Streams (O_XATTR)?

[Cedric Blancher]

On 2 December 2013 16:21, Christoph Hellwig <hch@infradead.org> wrote:
> On Mon, Dec 02, 2013 at 03:27:20PM +0100, Sebastian Feld wrote:
>> This isn't a Solaris-specific extension, its part of the original Sun
>> NFSv4 spec. Unfortunately the ARC/ARchitecture Cases from
>> Opensolaris.org are no longer available, otherwise the background,
>> e.g. feature parity with CIFS/NTFS, and the overall usefulness of such
>> a feature, would be clearer.
>
> It's a dumb part of the spec, and Linux has no intent support pretty
> braindead file/directory mixups.  Just store all your separate streams
> in separate files, that's how it's implemented underneath anyway.

Please. Please do me the favour and not rule something out that way.
Please hear the arguments and have a discussion.

Ced
-- 
Cedric Blancher <cedric.blancher@gmail.com>
Institute Pasteur

Re: Linux client access to NFSv4 Alternate Data Streams (O_XATTR)?

[Christoph Hellwig]

On Mon, Dec 02, 2013 at 08:27:22PM +0100, Cedric Blancher wrote:
> Please. Please do me the favour and not rule something out that way.
> Please hear the arguments and have a discussion.

If you can come up with good argument go ahead.  But your incoherent
rehearsing of old fairy tails in the other part of the thread doesn't
seem to get us anywhere.

Re: Linux client access to NFSv4 Alternate Data Streams (O_XATTR)?

[Trond Myklebust]

On Dec 2, 2013, at 9:27, Sebastian Feld <sebastian.n.feld@gmail.com> wrote:

> On Mon, Dec 2, 2013 at 2:29 PM, Trond Myklebust
> <trond.myklebust@primarydata.com> wrote:
>> 
>> On Dec 2, 2013, at 7:13, Joshuah Hurst <joshhurst@gmail.com> wrote:
>> 
>>> We need to access NFSv4 Alternate Data Streams (what Solaris,
>>> NexentaOS, Omnios and SmartOS can openat() with the O_XATTR flag) from
>>> a (Suse) Linux client.
>>> 
>>> OS is Suse Linux 12.3, x86-64, 64bit
>>> 
>>> Does anyone know how to archive this?
>> 
>> Why can’t you access Solaris-specific extensions from a Solaris client?
> 
> This isn't a Solaris-specific extension, its part of the original Sun
> NFSv4 spec. Unfortunately the ARC/ARchitecture Cases from
> Opensolaris.org are no longer available, otherwise the background,
> e.g. feature parity with CIFS/NTFS, and the overall usefulness of such
> a feature, would be clearer.

The open(O_XATTR) _is_ a Solaris specific extension. It isn’t something that we have been planning to support on Linux.

> There are many many applications coming from either the Windows world
> or the HPC camp (like nih.org or GE Healthcare) who mandatory rely on
> the existence of this feature (well, at least enough so that AT&T
> cloud services and the related toolchain (e.g. AST, including ksh93)
> now have extensive support for O_XATTR).

What do they use it for? Last I heard, Microsoft was deprecating the use of streams. I’m assuming that means they plan to get rid of it.

Cheers
  Trond

Re: Linux client access to NFSv4 Alternate Data Streams (O_XATTR)?

[Cedric Blancher]

On 2 December 2013 17:07, Trond Myklebust
<trond.myklebust@primarydata.com> wrote:
>
> On Dec 2, 2013, at 9:27, Sebastian Feld <sebastian.n.feld@gmail.com> wrote:
>
>> On Mon, Dec 2, 2013 at 2:29 PM, Trond Myklebust
>> <trond.myklebust@primarydata.com> wrote:
>>>
>>> On Dec 2, 2013, at 7:13, Joshuah Hurst <joshhurst@gmail.com> wrote:
>>>
>>>> We need to access NFSv4 Alternate Data Streams (what Solaris,
>>>> NexentaOS, Omnios and SmartOS can openat() with the O_XATTR flag) from
>>>> a (Suse) Linux client.
>>>>
>>>> OS is Suse Linux 12.3, x86-64, 64bit
>>>>
>>>> Does anyone know how to archive this?
>>>
>>> Why can’t you access Solaris-specific extensions from a Solaris client?
>>
>> This isn't a Solaris-specific extension, its part of the original Sun
>> NFSv4 spec. Unfortunately the ARC/ARchitecture Cases from
>> Opensolaris.org are no longer available, otherwise the background,
>> e.g. feature parity with CIFS/NTFS, and the overall usefulness of such
>> a feature, would be clearer.
>
> The open(O_XATTR) _is_ a Solaris specific extension. It isn’t something that we have been planning to support on Linux.

When NFS version 4 was conceived by SUN long ago it was already
decided that Alternate Data Streams should be a mandatory core
feature. Alternate Data Streams were officially supported in Solaris 9
(with most kernel parts already added with Solaris 8 updates, minus
implementations in the various file systems; a custom filesystem
however can use ADS on S8 using the S9 includes) and NFSv4 development
ran in parallel, together with the spec which would've introduced that
feature as part of the next Single Unix Standard.
The SUS spec itself was more or less "grounded" when SUN's POSIX team
was laid off (the sad day of Fri, Jan 23, 2009) as a desperate measure
to save money, but that didn't invalidate the valid concept or idea of
Alternate Data Streams.

What's *sad* is that there is a lot of FUD spread related to Alternate
Data Streams, usually from the camp which wishes to promote Extended
Attributes - which are not even closely related nor a competition -
both serve different purposes and should be able to exist happily
alongside each other.

>
>> There are many many applications coming from either the Windows world
>> or the HPC camp (like nih.org or GE Healthcare) who mandatory rely on
>> the existence of this feature (well, at least enough so that AT&T
>> cloud services and the related toolchain (e.g. AST, including ksh93)
>> now have extensive support for O_XATTR).
>
> What do they use it for?

Usually to provide per-file context data, stuff like cookies (like
Internet Explorer does), tags or per application index files. That
doesn't mean they are small - as you can read in
http://permalink.gmane.org/gmane.os.freebsd.devel.hackers/51891 such
files can be in the TB range (OK, that's CERN for you, but the usage
in the nih.gov toolchain can easily hit a few dozens GB as well if the
parent germ database file is a few hundred GB).

> Last I heard, Microsoft was deprecating the use of streams. I’m assuming that means they plan to get rid of it.

Could you please give me an URL for this? The comments we (Institute
Pasteur) got from Microsoft and what's behind their support paywall
indicate that they intend to extend that feature with more support in
tools and applications. This matches the recent flurry of new
developments from AT&T Research, CERN and others in that direction. I
think Microsoft would be clubbed to death by their own customers if
they try to EOF that feature...

Ced
-- 
Cedric Blancher <cedric.blancher@gmail.com>
Institute Pasteur

Re: Linux client access to NFSv4 Alternate Data Streams (O_XATTR)?

[Trond Myklebust]

On Dec 2, 2013, at 14:24, Cedric Blancher <cedric.blancher@gmail.com> wrote:

> On 2 December 2013 17:07, Trond Myklebust
> <trond.myklebust@primarydata.com> wrote:
>> 
>> On Dec 2, 2013, at 9:27, Sebastian Feld <sebastian.n.feld@gmail.com> wrote:
>> 
>>> On Mon, Dec 2, 2013 at 2:29 PM, Trond Myklebust
>>> <trond.myklebust@primarydata.com> wrote:
>>>> 
>>>> On Dec 2, 2013, at 7:13, Joshuah Hurst <joshhurst@gmail.com> wrote:
>>>> 
>>>>> We need to access NFSv4 Alternate Data Streams (what Solaris,
>>>>> NexentaOS, Omnios and SmartOS can openat() with the O_XATTR flag) from
>>>>> a (Suse) Linux client.
>>>>> 
>>>>> OS is Suse Linux 12.3, x86-64, 64bit
>>>>> 
>>>>> Does anyone know how to archive this?
>>>> 
>>>> Why can’t you access Solaris-specific extensions from a Solaris client?
>>> 
>>> This isn't a Solaris-specific extension, its part of the original Sun
>>> NFSv4 spec. Unfortunately the ARC/ARchitecture Cases from
>>> Opensolaris.org are no longer available, otherwise the background,
>>> e.g. feature parity with CIFS/NTFS, and the overall usefulness of such
>>> a feature, would be clearer.
>> 
>> The open(O_XATTR) _is_ a Solaris specific extension. It isn’t something that we have been planning to support on Linux.
> 
> When NFS version 4 was conceived by SUN long ago it was already
> decided that Alternate Data Streams should be a mandatory core
> feature. Alternate Data Streams were officially supported in Solaris 9
> (with most kernel parts already added with Solaris 8 updates, minus
> implementations in the various file systems; a custom filesystem
> however can use ADS on S8 using the S9 includes) and NFSv4 development
> ran in parallel, together with the spec which would've introduced that
> feature as part of the next Single Unix Standard.
> The SUS spec itself was more or less "grounded" when SUN's POSIX team
> was laid off (the sad day of Fri, Jan 23, 2009) as a desperate measure
> to save money, but that didn't invalidate the valid concept or idea of
> Alternate Data Streams.
> 
> What's *sad* is that there is a lot of FUD spread related to Alternate
> Data Streams, usually from the camp which wishes to promote Extended
> Attributes - which are not even closely related nor a competition -
> both serve different purposes and should be able to exist happily
> alongside each other.
> 

Speaking of FUD. I really don’t care how you read the NFSv4 spec, and yes, I’ve read it cover to cover _many_ times; nothing there says that named attributes are mandatory to implement.

>>> There are many many applications coming from either the Windows world
>>> or the HPC camp (like nih.org or GE Healthcare) who mandatory rely on
>>> the existence of this feature (well, at least enough so that AT&T
>>> cloud services and the related toolchain (e.g. AST, including ksh93)
>>> now have extensive support for O_XATTR).
>> 
>> What do they use it for?
> 
> Usually to provide per-file context data, stuff like cookies (like
> Internet Explorer does), tags or per application index files. That
> doesn't mean they are small - as you can read in
> http://permalink.gmane.org/gmane.os.freebsd.devel.hackers/51891 such
> files can be in the TB range (OK, that's CERN for you, but the usage
> in the nih.gov toolchain can easily hit a few dozens GB as well if the
> parent germ database file is a few hundred GB).

Why can you not just package the whole thing in a directory? You are treating that file as if it were a directory. The only difference is that you use open(XATTR) in order to access the directory rather than using a real pathname.

>> Last I heard, Microsoft was deprecating the use of streams. I’m assuming that means they plan to get rid of it.
> 
> Could you please give me an URL for this? The comments we (Institute
> Pasteur) got from Microsoft and what's behind their support paywall
> indicate that they intend to extend that feature with more support in
> tools and applications. This matches the recent flurry of new
> developments from AT&T Research, CERN and others in that direction. I
> think Microsoft would be clubbed to death by their own customers if
> they try to EOF that feature...

They already threw it out of their server grade ReFS filesystem: http://en.wikipedia.org/wiki/ReFS

Trond