Re: DirectoryStorage on NFS?

J C Lawrence <[email protected]>
Newsgroups gmane.comp.web.zope.zodb.dirstorage
Message-ID <[email protected]>
On Sat, 6 Nov 2004 00:27:41 +0000
Toby Dickenson <[email protected]> wrote:
> On Friday 05 Nov 2004 20:57, J C Lawrence wrote:
>> On Thu, 4 Nov 2004 08:29:21 +0000 Toby Dickenson <[email protected]>

> There are few guaranteed atomic operations between independent NFS
> clients, or between NFS clients and local (non-NFS) access to the same
> files.

Quite.  I did some work on this way back when in order to determine a
safe locking schema which would work correctly in all the standard cases
encluding NFS clusters.  In the end, after checking all the versions and
most of the platforms the only thing we found that we could actually
rely on was creat(2) being atomic.  Nothing else is reliable across the
various platforms and NFS versions.

Well, until recently.  NFS v4 changes a few things as it is no longer
stateless.

> Im sure that means you dont want to allow concurrent access to your
> storage data from seperate NFS clients.

Yup, and we're not going to.

>> It works!

> Hurrah. A configuration option for this will be in 1.1.13

Excellent.  Thanks for your help.

--
J C Lawrence
---------(*)                Satan, oscillate my metallic sonatas.
[email protected]               He lived as a devil, eh?
http://www.kanga.nu/~claw/  Evil is a name of a foeman, as I live.


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