dfs in R2 realtime file access question

No DFS doesn't currently support "Locking Files"
--
Regards
Christoffer Andersson
Microsoft MVP - Directory Services

No email replies please - reply in the newsgroup
------------------------------------------------
http://www.chrisse.se - Active Directory Resources

Post by Gabriel
Right now if one user tries to open a file that someone else has open in
Word the user will be notifed that the file is already open and the second
user can open the file in read only.
Using DFS If two users in two seperate offices open try to open the same
file will they know the file is already open in the other office?

Marcel

2006-03-30 06:40:09 UTC

Post by chriss3 [MVP]
No DFS doesn't currently support "Locking Files"
--
Regards
Christoffer Andersson
Microsoft MVP - Directory Services
No email replies please - reply in the newsgroup
------------------------------------------------
http://www.chrisse.se - Active Directory Resources

Post by Gabriel
Right now if one user tries to open a file that someone else has open in
Word the user will be notifed that the file is already open and the
second user can open the file in read only.
Using DFS If two users in two seperate offices open try to open the same
file will they know the file is already open in the other office?

Indeed, but word doesn't work that way. It places a hidden file in the
folder where the document resides telling others using word that it is in
use and by whom. So if you open a document, the hidden file will also be
replicated.

Marcel

Gabriel

2006-03-30 15:30:39 UTC

Word was just an example. I'm more concerned about CAD drawings. Thanks
for the input!

Gabriel

Post by Marcel

Post by Gabriel
Right now if one user tries to open a file that someone else has open in
Word the user will be notifed that the file is already open and the
second user can open the file in read only.
Using DFS If two users in two seperate offices open try to open the same
file will they know the file is already open in the other office?

DAVID A BERMINGHAM

2006-03-30 17:54:28 UTC

So what happens if two people are working on the same document at the same
time? Does the last person to save the document win and the other document
is overwritten?
--
David Bermingham, MCSE, MCSA:Messaging
Senior Windows System Engineer
SteelEye Technology, HA and DR for Windows and Linux
www.steeleye.com

Didier GAUTIER [MSFT]

2006-03-31 06:17:34 UTC

Hi,

Actually, DFS is not involved here. It happens exactly the same way as when
two clients are connected to the same share of a server and open the same
file. It's up to the application to implement a locking mechanism. Some apps
(like Word for example does). If it doesn't then the last writer wins.
--
Thanks,

Didier GAUTIER
Microsoft European Global Technical Support Center
This posting is provided "AS IS" with no warranties, and confers no rights.

Post by DAVID A BERMINGHAM
So what happens if two people are working on the same document at the same
time? Does the last person to save the document win and the other document
is overwritten?
--
David Bermingham, MCSE, MCSA:Messaging
Senior Windows System Engineer
SteelEye Technology, HA and DR for Windows and Linux
www.steeleye.com

Post by Gabriel
Right now if one user tries to open a file that someone else has open in
Word the user will be notifed that the file is already open and the

second

Post by Gabriel
user can open the file in read only.
Using DFS If two users in two seperate offices open try to open the same
file will they know the file is already open in the other office?

DAVID A BERMINGHAM

2006-03-31 15:19:19 UTC

So a user in London opens up a Word document on a DFS share and it is
retrieved from the local server in London. Then a user is NY goes to the
same namespace and opens the "same" Word document, which is actually a DFS-R
replicated copy that sits on the local NY server.

If I understand you correctly, the NY user should get a message that the
file is already opened by someone else and can only be opened in read-only
mode, is that correct? Is this new functioanlity with R2 or has it always
behaved this way?

Post by Didier GAUTIER [MSFT]
Hi,
Actually, DFS is not involved here. It happens exactly the same way as when
two clients are connected to the same share of a server and open the same
file. It's up to the application to implement a locking mechanism. Some apps
(like Word for example does). If it doesn't then the last writer wins.
--
Thanks,
Didier GAUTIER
Microsoft European Global Technical Support Center
This posting is provided "AS IS" with no warranties, and confers no rights.

Post by Gabriel
Right now if one user tries to open a file that someone else has open in
Word the user will be notifed that the file is already open and the

second

Post by Gabriel
user can open the file in read only.
Using DFS If two users in two seperate offices open try to open the same
file will they know the file is already open in the other office?

Didier GAUTIER [MSFT]

2006-03-31 16:14:45 UTC

Sorry, I didn't make myself clear enough. The lock mechanism implemented by
Word only works between files located on the same share. In your case, Word,
when opening the file from the share of the server in London will not get
notified that the file located on the share of the US server has already
been opened. Both users will then close their own version with their
changes. When DFS-R replication schedule opens, DFS-R will detect a
conflict. It will resolve it by moving the file that has been closed first
to the "dfsr private\conflicts & deleted" directory of the replicated folder
and keep the other one.

We don't implement a distributed lock manager service that would make
servers aware of the locks across the network. Instead, we manage conflicts.
--
Thanks,

Didier GAUTIER
Microsoft European Global Technical Support Center
This posting is provided "AS IS" with no warranties, and confers no rights.

Post by DAVID A BERMINGHAM
So a user in London opens up a Word document on a DFS share and it is
retrieved from the local server in London. Then a user is NY goes to the
same namespace and opens the "same" Word document, which is actually a DFS-R
replicated copy that sits on the local NY server.
If I understand you correctly, the NY user should get a message that the
file is already opened by someone else and can only be opened in read-only
mode, is that correct? Is this new functioanlity with R2 or has it always
behaved this way?

Post by Didier GAUTIER [MSFT]
Hi,
Actually, DFS is not involved here. It happens exactly the same way as

when

Post by Didier GAUTIER [MSFT]
two clients are connected to the same share of a server and open the same
file. It's up to the application to implement a locking mechanism. Some

apps

Post by Didier GAUTIER [MSFT]
(like Word for example does). If it doesn't then the last writer wins.
--
Thanks,
Didier GAUTIER
Microsoft European Global Technical Support Center
This posting is provided "AS IS" with no warranties, and confers no

rights.

Post by DAVID A BERMINGHAM
So what happens if two people are working on the same document at the

same

Post by DAVID A BERMINGHAM
time? Does the last person to save the document win and the other document
is overwritten?
--
David Bermingham, MCSE, MCSA:Messaging
Senior Windows System Engineer
SteelEye Technology, HA and DR for Windows and Linux
www.steeleye.com

Post by Gabriel
Right now if one user tries to open a file that someone else has
open
in
Word the user will be notifed that the file is already open and the

second

Post by Gabriel
user can open the file in read only.
Using DFS If two users in two seperate offices open try to open the same
file will they know the file is already open in the other office?

Marcel

2006-04-04 08:31:51 UTC

Post by Didier GAUTIER [MSFT]
Sorry, I didn't make myself clear enough. The lock mechanism implemented
by Word only works between files located on the same share. In your case,
Word, when opening the file from the share of the server in London will
not get notified that the file located on the share of the US server has
already been opened. Both users will then close their own version with
their changes. When DFS-R replication schedule opens, DFS-R will detect a
conflict. It will resolve it by moving the file that has been closed first
to the "dfsr private\conflicts & deleted" directory of the replicated
folder and keep the other one.
We don't implement a distributed lock manager service that would make
servers aware of the locks across the network. Instead, we manage conflicts.

I''ve been retesting this and regretfully must concur with what is written
above.

Not even the way of file "locking" that Word uses works over dfs because the
file placed in the folder where the opened document resides is not
replicated to other servers. Probably because the file is in use... It will
work if both users are directed to the same server.

If I recall correctly, AutoCAD does use some sort of temporary files for
opened drawings. Maybe you could test the locking capabilities of AutoCAD
with a simple network share....

Marcel

Ned Pyle (MSFT)

2006-04-04 20:22:39 UTC

One suggestion I have (and this is based on some very loose conversations I
had with the beta team back when R2 was being developed) was to use MS
Sharepoint Server as a front end to DFS (with DFSR replication). SP allows
file checkouts and locks files, so that users could check out a file
read-only or for editing. Since SP would lock the file, other users would
only be able to read them int he meantime, and you avoid the whole 'last
writer wins' scenario.

In theory at least - to reiterate, I've not tried to implement this. Perhaps
someone here has?

Post by Marcel

Post by Didier GAUTIER [MSFT]
Sorry, I didn't make myself clear enough. The lock mechanism implemented
by Word only works between files located on the same share. In your case,
Word, when opening the file from the share of the server in London will
not get notified that the file located on the share of the US server has
already been opened. Both users will then close their own version with
their changes. When DFS-R replication schedule opens, DFS-R will detect a
conflict. It will resolve it by moving the file that has been closed
first to the "dfsr private\conflicts & deleted" directory of the
replicated folder and keep the other one.
We don't implement a distributed lock manager service that would make
servers aware of the locks across the network. Instead, we manage conflicts.

I''ve been retesting this and regretfully must concur with what is written
above.
Not even the way of file "locking" that Word uses works over dfs because
the file placed in the folder where the opened document resides is not
replicated to other servers. Probably because the file is in use... It
will work if both users are directed to the same server.
If I recall correctly, AutoCAD does use some sort of temporary files for
opened drawings. Maybe you could test the locking capabilities of AutoCAD
with a simple network share....
Marcel

BrianH

2006-04-12 02:13:02 UTC

I'm replicating AutoCAD file and I get share violations on the .DWL files.
DWL is a drawing Lock file. created when a DWG is opened. I think the DWL
remains open and is not able to replicate. Sharepoint is not a realistic
solution for cad files becouse of the number of reference files (XREF)
associated with read/write cad file. I'm going ti investigate the options
with CIFS.

Brian

Post by Ned Pyle (MSFT)
One suggestion I have (and this is based on some very loose conversations I
had with the beta team back when R2 was being developed) was to use MS
Sharepoint Server as a front end to DFS (with DFSR replication). SP allows
file checkouts and locks files, so that users could check out a file
read-only or for editing. Since SP would lock the file, other users would
only be able to read them int he meantime, and you avoid the whole 'last
writer wins' scenario.
In theory at least - to reiterate, I've not tried to implement this. Perhaps
someone here has?

Post by Marcel

Post by Didier GAUTIER [MSFT]
Sorry, I didn't make myself clear enough. The lock mechanism implemented
by Word only works between files located on the same share. In your case,
Word, when opening the file from the share of the server in London will
not get notified that the file located on the share of the US server has
already been opened. Both users will then close their own version with
their changes. When DFS-R replication schedule opens, DFS-R will detect a
conflict. It will resolve it by moving the file that has been closed
first to the "dfsr private\conflicts & deleted" directory of the
replicated folder and keep the other one.
We don't implement a distributed lock manager service that would make
servers aware of the locks across the network. Instead, we manage conflicts.

I''ve been retesting this and regretfully must concur with what is written
above.
Not even the way of file "locking" that Word uses works over dfs because
the file placed in the folder where the opened document resides is not
replicated to other servers. Probably because the file is in use... It
will work if both users are directed to the same server.
If I recall correctly, AutoCAD does use some sort of temporary files for
opened drawings. Maybe you could test the locking capabilities of AutoCAD
with a simple network share....
Marcel

Gabriel

2006-05-10 16:18:48 UTC

Is there a 3rd party addon that adds a distributed lock manager service to
dfs?

Thanks,

Gabriel

Post by Didier GAUTIER [MSFT]
Hi,
Actually, DFS is not involved here. It happens exactly the same way as

when

Post by Didier GAUTIER [MSFT]
two clients are connected to the same share of a server and open the same
file. It's up to the application to implement a locking mechanism. Some

apps

rights.

Post by DAVID A BERMINGHAM
So what happens if two people are working on the same document at the

same

Post by Gabriel
Right now if one user tries to open a file that someone else has
open
in
Word the user will be notifed that the file is already open and the

second

Post by Gabriel
user can open the file in read only.
Using DFS If two users in two seperate offices open try to open the same
file will they know the file is already open in the other office?

Ned Pyle (MSFT)

2006-05-12 15:43:19 UTC

Hi,

Not to my knowledge, as this is a sort of algorythmic holy grail if it's to
be done right. There is an entire MS Research team cranking away on this
currently:

http://research.microsoft.com/camdis/

Specifically, the ICECUBE project. Interesting reads to be found in the
Publications section...

Ned

Post by Gabriel
Is there a 3rd party addon that adds a distributed lock manager service to
dfs?
Thanks,
Gabriel

Post by Didier GAUTIER [MSFT]
Sorry, I didn't make myself clear enough. The lock mechanism implemented
by Word only works between files located on the same share. In your case,
Word, when opening the file from the share of the server in London will
not get notified that the file located on the share of the US server has
already been opened. Both users will then close their own version with
their changes. When DFS-R replication schedule opens, DFS-R will detect a
conflict. It will resolve it by moving the file that has been closed
first to the "dfsr private\conflicts & deleted" directory of the
replicated folder and keep the other one.
We don't implement a distributed lock manager service that would make
servers aware of the locks across the network. Instead, we manage conflicts.
--
Thanks,
Didier GAUTIER
Microsoft European Global Technical Support Center
This posting is provided "AS IS" with no warranties, and confers no rights.

Post by Didier GAUTIER [MSFT]
Hi,
Actually, DFS is not involved here. It happens exactly the same way as

when

Post by Didier GAUTIER [MSFT]
two clients are connected to the same share of a server and open the same
file. It's up to the application to implement a locking mechanism. Some

apps

rights.

Post by DAVID A BERMINGHAM
So what happens if two people are working on the same document at the

same

Post by Gabriel
Right now if one user tries to open a file that someone else has
open
in
Word the user will be notifed that the file is already open and the

second