NFS clients' use of fs_locations?

NFS clients' use of fs_locations?

[Jeff Garzik]

According to the NFSv4 spec (section 6.1), regarding fs_locations,

	On first access of the filesystem, the client should obtain the
	value of the fs_locations attribute. If, in the future, the
	client finds the server unresponsive, the client may attempt to
	use another server specified by fs_locations.

Does any known client actually fail over to another fs_location, as 
described here?

I am implementing the server side of this...  AFAICT Linux barely uses 
fs_locations, and Solaris just crashes.

	Jeff



_______________________________________________
NFSv4 mailing list
NFSv4@linux-nfs.org
http://linux-nfs.org/cgi-bin/mailman/listinfo/nfsv4

Re: NFS clients' use of fs_locations?

[J. Bruce Fields]

On Wed, Feb 11, 2009 at 03:00:50PM -0500, Jeff Garzik wrote:
> According to the NFSv4 spec (section 6.1), regarding fs_locations,
> 
> 	On first access of the filesystem, the client should obtain the
> 	value of the fs_locations attribute. If, in the future, the
> 	client finds the server unresponsive, the client may attempt to
> 	use another server specified by fs_locations.
> 
> Does any known client actually fail over to another fs_location, as 
> described here?
> 
> I am implementing the server side of this...  AFAICT Linux barely uses 
> fs_locations, and Solaris just crashes.

Yeah, Linux only uses fs_locations when it crosses a mountpoint to a new
filesystem and finds that filesystem is only available elsewhere.

Maybe AIX?

--b.
_______________________________________________
NFSv4 mailing list
NFSv4@linux-nfs.org
http://linux-nfs.org/cgi-bin/mailman/listinfo/nfsv4

Re: NFS clients' use of fs_locations?

[Trond Myklebust]

On Wed, 2009-02-11 at 15:00 -0500, Jeff Garzik wrote:
> According to the NFSv4 spec (section 6.1), regarding fs_locations,
> 
> 	On first access of the filesystem, the client should obtain the
> 	value of the fs_locations attribute. If, in the future, the
> 	client finds the server unresponsive, the client may attempt to
> 	use another server specified by fs_locations.
> 
> Does any known client actually fail over to another fs_location, as 
> described here?
> 
> I am implementing the server side of this...  AFAICT Linux barely uses 
> fs_locations, and Solaris just crashes.

Hi Jeff,

I'm working on finishing the migration code, and expect to have it ready
soon.
Until that, though, Bruce's suggestion of AIX is probably your best bet.
AFAIK, they've had migration support in their client for several years.

Cheers
  Trond

_______________________________________________
NFSv4 mailing list
NFSv4@linux-nfs.org
http://linux-nfs.org/cgi-bin/mailman/listinfo/nfsv4

Re: NFS clients' use of fs_locations?

[Jeff Garzik]

Trond Myklebust wrote:
> On Wed, 2009-02-11 at 15:00 -0500, Jeff Garzik wrote:
>> According to the NFSv4 spec (section 6.1), regarding fs_locations,
>>
>> 	On first access of the filesystem, the client should obtain the
>> 	value of the fs_locations attribute. If, in the future, the
>> 	client finds the server unresponsive, the client may attempt to
>> 	use another server specified by fs_locations.
>>
>> Does any known client actually fail over to another fs_location, as 
>> described here?
>>
>> I am implementing the server side of this...  AFAICT Linux barely uses 
>> fs_locations, and Solaris just crashes.
> 
> Hi Jeff,
> 
> I'm working on finishing the migration code, and expect to have it ready
> soon.

Neat!  Will that include the simple fail-over actions described above?


> Until that, though, Bruce's suggestion of AIX is probably your best bet.
> AFAIK, they've had migration support in their client for several years.

Thanks!  Any idea at all if AIX client supports fail-over, or simply 
migration based on NFS4ERR_MOVED?

Time to figure out how to access AIX NFS client......  :)

	Jeff

Re: NFS clients' use of fs_locations?

[Trond Myklebust]

On Wed, 2009-02-11 at 16:30 -0500, Jeff Garzik wrote:
> Trond Myklebust wrote:
> > On Wed, 2009-02-11 at 15:00 -0500, Jeff Garzik wrote:
> >> According to the NFSv4 spec (section 6.1), regarding fs_locations,
> >>
> >> 	On first access of the filesystem, the client should obtain the
> >> 	value of the fs_locations attribute. If, in the future, the
> >> 	client finds the server unresponsive, the client may attempt to
> >> 	use another server specified by fs_locations.
> >>
> >> Does any known client actually fail over to another fs_location, as 
> >> described here?
> >>
> >> I am implementing the server side of this...  AFAICT Linux barely uses 
> >> fs_locations, and Solaris just crashes.
> > 
> > Hi Jeff,
> > 
> > I'm working on finishing the migration code, and expect to have it ready
> > soon.
> 
> Neat!  Will that include the simple fail-over actions described above?

Yes. As well as full state recovery etc on migration...

> > Until that, though, Bruce's suggestion of AIX is probably your best bet.
> > AFAIK, they've had migration support in their client for several years.
> 
> Thanks!  Any idea at all if AIX client supports fail-over, or simply 
> migration based on NFS4ERR_MOVED?
> 
> Time to figure out how to access AIX NFS client......  :)

Maybe Steve French (sfrench@samba.org) can help you out? I think he's
still working for IBM, and I believe his office used to be in the same
complex as the AIX nfs developers in Austin...

Cheers
    Trond