On Thu, Jul 22, 2010 at 12:58:50PM -0400, Trond Myklebust wrote:
>
> That would make it impossible to export the filesystem with NFSv2 and
> v3. They do rely on ctime checking for certain operations (e.g. deciding
> when to invalidate access and acl caches). NFSv4 needs this too if the
> filesystem has no dedicated change attribute.
>
> Still, I suppose the market for exporting the same filesystem with both
> NFS and Samba is limited...
Ask NetApp about that :-). They have built a rather large
business on just that fact :-).
Jeremy.
On Thu, Jul 22, 2010 at 11:02:04AM -0700, Jeremy Allison wrote:
> On Thu, Jul 22, 2010 at 12:58:50PM -0400, Trond Myklebust wrote:
> >
> > That would make it impossible to export the filesystem with NFSv2 and
> > v3. They do rely on ctime checking for certain operations (e.g. deciding
> > when to invalidate access and acl caches). NFSv4 needs this too if the
> > filesystem has no dedicated change attribute.
> >
> > Still, I suppose the market for exporting the same filesystem with both
> > NFS and Samba is limited...
>
> Ask NetApp about that :-). They have built a rather large
> business on just that fact :-).
Jeremy, how many hours have you spent getting "posix
locking" to the point where it is now? :-)
Volker
P.S: For those not aware, "posix locking = yes" is
cross-protocol byte range locking done by smbd to co-operate
with local processes and NFS.
On Thursday 2010-07-22 20:02, Jeremy Allison wrote:
>On Thu, Jul 22, 2010 at 12:58:50PM -0400, Trond Myklebust wrote:
>>
>> That would make it impossible to export the filesystem with NFSv2 and
>> v3. They do rely on ctime checking for certain operations (e.g. deciding
>> when to invalidate access and acl caches). NFSv4 needs this too if the
>> filesystem has no dedicated change attribute.
>>
>> Still, I suppose the market for exporting the same filesystem with both
>> NFS and Samba is limited...
>
>Ask NetApp about that :-). They have built a rather large
>business on just that fact :-).
What would ZFS do? :p
On Thu, 2010-07-22 at 20:04 +0200, Volker Lendecke wrote:
> On Thu, Jul 22, 2010 at 11:02:04AM -0700, Jeremy Allison wrote:
> > On Thu, Jul 22, 2010 at 12:58:50PM -0400, Trond Myklebust wrote:
> > >
> > > That would make it impossible to export the filesystem with NFSv2 and
> > > v3. They do rely on ctime checking for certain operations (e.g. deciding
> > > when to invalidate access and acl caches). NFSv4 needs this too if the
> > > filesystem has no dedicated change attribute.
> > >
> > > Still, I suppose the market for exporting the same filesystem with both
> > > NFS and Samba is limited...
> >
> > Ask NetApp about that :-). They have built a rather large
> > business on just that fact :-).
>
> Jeremy, how many hours have you spent getting "posix
> locking" to the point where it is now? :-)
>
> Volker
>
> P.S: For those not aware, "posix locking = yes" is
> cross-protocol byte range locking done by smbd to co-operate
> with local processes and NFS.
I said "limited", not "non-existent".
The fact remains that most of us would be hard pressed to name an
application that requires you to share the same dataset to both
Windows/CIFS and posix NFS clients. Everything from ACL models through
caseless vs case-aware filesystems and Windows vs posix locking
semantics tends to discourage mixing the two environments.
Trond
>>>>> "Jeremy" == Jeremy Allison <[email protected]> writes:
Jeremy> On Thu, Jul 22, 2010 at 12:58:50PM -0400, Trond Myklebust wrote:
>>
>> That would make it impossible to export the filesystem with NFSv2 and
>> v3. They do rely on ctime checking for certain operations (e.g. deciding
>> when to invalidate access and acl caches). NFSv4 needs this too if the
>> filesystem has no dedicated change attribute.
>>
>> Still, I suppose the market for exporting the same filesystem with both
>> NFS and Samba is limited...
Jeremy> Ask NetApp about that :-). They have built a rather large
Jeremy> business on just that fact :-).
And it does work, as long as you also go with either unix or windows
semantics for the security and permissions bits. If you try to use
the mixed-mode, you're in for a world of hurt.
Oh yeah, Netapp still uses dump/restore for it's backups. :] Though
whether it's still dependent on the optimization of ctime being used
to know whether to just dump the inode only or not, I can't say.
John
On 7/22/10 2:59 PM, Trond Myklebust wrote:
> The fact remains that most of us would be hard pressed to name an
> application
Microsoft Office?
> that requires you to share the same dataset to both
> Windows/CIFS and posix NFS clients.
NFS client: Mac OS X (NFSv3, since v4 on it is still alpha *cough*).
> tends to discourage mixing the two environments.
Or is "discourage" not strong enough term to describe that we shouldn't
be doing this?
-Phil