Understanding (the Lack of) Distributed File Locking in DFSR

re: Understanding (the Lack of) Distributed File Locking in DFSR

Jeff.Miles — Fri, 15 Oct 2010 22:27:07 GMT

robburdett,

I just saw your comment. We never ended up purchasing the GlobalScape product due to the negatives I mentioned in my last comment.

We continue to use DFSR with limited use of PeerLock on high-collaboration folders only. This has been working well for us.

re: Understanding (the Lack of) Distributed File Locking in DFSR

robburdett — Thu, 09 Sep 2010 16:27:42 GMT

JMiles,

Hi it's been a few months now. Would you still recommend Globalscape as a product? how resource hungry is it please? I have a client currently using Peersync (80% CPU usage!!)

but no file locking - they are having a nightmare.

They are a small company 12 users in one site 6 in another with a server at each site.

Many Thanks in advance

re: Understanding (the Lack of) Distributed File Locking in DFSR

Jeff.Miles — Tue, 23 Feb 2010 15:10:02 GMT

Just as an update regarding the Globalscape product, we will most likely not be purchasing it. After some research, the following negatives were determined:

- An agent and server is required, so for our hub site, we would need to store 900GB of data for the server, and 900GB of data for the agent

- Only 1 file transfer occurs at a time, as opposed to DFSR's 16 concurrent transfers

- The software cannot be run as a service on Windows Server 2008. It will only run as an application with a logged on user.

I'm a little disappointed, as there really aren't many other options for branch office replication. It must not be as popular as I had assumed when we chose this infrastructure. I just find it hard to believe that many companies would sacrifice LAN speed access for centralised data, when collaboration is necessary.

DFSR for the most part is a great solution, it's just that I don't think it was designed for our use case, with 100's of files open at once causing sharing violations and backlogs. If only we could tweak how often opened files are retried (and extend that period), and have native file locking.

re: Understanding (the Lack of) Distributed File Locking in DFSR

NedPyle [MSFT] — Wed, 02 Dec 2009 23:35:51 GMT

SOunds interesting - I'm very interested in hearing your results, especially regarding bandwidth savings of DFSR's RDC and compression versus GlobalScape's mechanisms. This would be most apparent when making small edits to large files.

In the end, I'm happy if you use DFSR or a third party, as long as you're using Windows. :)

- Ned

re: Understanding (the Lack of) Distributed File Locking in DFSR

Jeff.Miles — Wed, 02 Dec 2009 22:31:52 GMT

AndrewN, you can reach me by emailing to jadus01 at hotmail.com (obfuscated to avoid spam bots).

We had quite a few problems after initially setting up Peerlock, with backlogs of 1000's of files caused by peerlock, but have that mostly figured out though.

We're still looking at alternatives, and I think we're going to begin testing GlobalScape WAFS product, in place of DFSR. It will do the replication, as well as file locking, and hopefully do so without all the sharing violations. One of the biggest things is apparently it will replicate files after a save, even if they're still open.

re: Understanding (the Lack of) Distributed File Locking in DFSR

AndrewN — Wed, 25 Nov 2009 00:32:23 GMT

Hi Jmiles

We have also been using Peerlock with DFS-R but recently it has begun doing strange things like not releasing locks and causing DFS-R to think an older file on the other is newer ect.

Can you please let me know your contact details I would like to talk to you.

Also has anyone used Peer Sync - it purports to add a lot of features in a replication engine such as versioning ect.

re: Understanding (the Lack of) Distributed File Locking in DFSR

NedPyle [MSFT] — Fri, 20 Nov 2009 14:32:09 GMT

It's possible that they weren't actually locking the file though - it depends on the user *application* to decide about locks. For example, two people can edit the same TXT file simultaneously if they are both using NOTEPAD.EXE, because that application does not lock files. It's not always a hard and fast rule.

re: Understanding (the Lack of) Distributed File Locking in DFSR

Bluetek — Fri, 20 Nov 2009 10:38:01 GMT

Thanks Ned for the quick response.

I take it that this has always been default behaviour and that there are no hotfixes which would have fixed an issue where file locking wasn't happening as in the case above where two users are accessing the same server, same file.

Thanks again.

re: Understanding (the Lack of) Distributed File Locking in DFSR

NedPyle [MSFT] — Thu, 19 Nov 2009 16:55:57 GMT

Yes, after the first user on A locks a file for WRITE, any subsequent users connecting to A will not be able to modify the file. At this point you are not dealing with DFSR in any way, but instead SMB behavior.

And thanks, I too hope are well. :)

re: Understanding (the Lack of) Distributed File Locking in DFSR

Bluetek — Thu, 19 Nov 2009 16:40:30 GMT

Hi Ned - Hope you're well.

I have a question over file locking.

Essentially the setup is relatively simple as follows:

All servers are running 2003R2.

There are 3 sites say A, B, C.

A= remote site

B= remote site

C= data center

Users only access servers in sites A or B only. DFS has been setup so that DFSR only replicates files between A&C or B&C so folders on A & B servers are unique and are only replicated to servers in site C.

If two users access the same file in Site A will a file lock occur for the second (and subsequent users)?

Essentially I am asking if any part of DFS (like DFSR)turns off file locking completely on a server!

I hope this makes sense.

Thanks in advance for your help.

Best Regards