SMB sharing drops connection in Windows 7/Vista/XP

Question

SMB sharing drops connection in Windows 7/Vista/XP

So interesting tidbit here. Apple Enterprise still hasn't gotten back to me with an answer on this one.

I have file sharing set up, a couple of different folders with some simple permissions. Nothing fancy. All shares work perfect under AFP and SMB on any Mac in the office. However, I have found on both Windows XP/Vista/7, large file transfers seem to drop the connection saying that either the file has changed or it was renamed or something along those lines, basically, it errors out and I can either skip the file or cancel the transfer. I've tested it on multiple machines with all same results. Here's a kicker, I even clean installed Windows 7 on two machines (so I know there are no software/hardware issues or malware) and it will exhibits the same behavior.

Any thoughts? I've done the exact same transfer either via Gigabit Ethernet and WiFi on the Mac using both protocols with no issues. I have a simple network:

Cisco Gb Ethernet Router
Cisco Gb Ethernet Switch (all traffic, including the server and all clients go through this switch, it is an unmanaged switch)
Linksys A/B/G/N WAP
Mac mini running 10.8.2 and 2.2.1 server (has all correct DNS and certificate settings)

The only thing I can think of is perhaps an issue with the PCs (which are 10/100) and the Gb Ethernet? Everything for the server appears to be functioning just fine?

Mac mini (Mid 2011), OS X Server

Posted on Feb 6, 2013 6:21 AM

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Answer 1

Best reply

Doc_Mo

Level 1

5 points

Feb 6, 2013 8:37 AM in response to Bryan Navarro

Hi Bryan,

i think your problem transfering large files (in my case >1 GB) is the same issue we discuss here:

https://discussions.apple.com/thread/4241958?start=15&tstart=0

If i transfer a file bigger than 1 GB from Windows (any version) to my mac SMB-Share at about 50-60% the copy stopps with an error.

Regards,

Mo

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Answer 2

Feb 6, 2013 10:21 AM in response to Doc_Mo

It's similar. I'm finding the most consistent errors when the Windows client is trying to download large items from the OS X ML Server. If I initiate a transfer either from another client or the server itself, it more often than not goes through.

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Answer 3

vizion8

Level 1

18 points

Jul 17, 2013 11:37 PM in response to Bryan Navarro

1. On the Windows machine, open Regedit, and go to \HKLM\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters\

2. Add a DWORD value called SessTimeout and set it for something like 3000 seconds

3. Restart workstation service

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Answer 4

Jul 18, 2013 6:46 AM in response to vizion8

Tested out great on Windows 7 with over 10 gigs of data. Gonna try it on a few more machines but this may be the fix. I'll update shortly.

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Answer 5

Jul 19, 2013 4:47 AM in response to vizion8

Thanks to Vizion8, looks like the issue is corrected. I thought it might be a timeout issue and sure enough, it seems to have been. Did multiple 10+ gig transfers simultaneously on the machines with no issue.

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Answer 6

Jul 19, 2013 6:21 AM in response to Bryan Navarro

Stress testing even more, I'm now running 3 PCs over SMB on the 10GB folder while a Mac is pulling via AFP - all the same data. No hiccups at all. If anyone has ideas on how to better stress test, let me know but for all intents and purposes, I think the issue is resolved.

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Answer 7

Aug 8, 2013 6:22 PM in response to Bryan Navarro

I agree that this fixes the file copy issue... but, I'm still finding that if I open large projects from my server from a client machine (a project that needs to access over 2 gigs of data and keep it open), the data goes offline.

And this only happens after maybe a few minutes.

Any ideas how to work around that???

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Answer 8

vizion8

Level 1

18 points

Aug 8, 2013 6:35 PM in response to Charlesdem

Try a longer timeout. Maybe 3 hours long.

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Answer 9

Aug 8, 2013 6:54 PM in response to vizion8

I did 36000... isn't that 600 minutes?

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Answer 10

Aug 9, 2013 5:01 AM in response to Bryan Navarro

I have to believe there's still a way to tweak this to work. Now it's just a matter of keeping the connection open to all those files. Copying works, though, which is nice, but not all that I need for full SMB functionality.

thanks for any thoughts on this.

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Answer 11

Aug 9, 2013 5:34 AM in response to Charlesdem

A few questions:

Does connecting via AFP from Mac to OS X Server allow you to open the file just fine (same connection method as you are trying to over PC, aka Wi-Fi or Ethernet)?
Does connecting via SMB from Mac to OS X Server all you to open the file just fine?

If those 2 work, then the problem may be somewhere on the Windows machine. Since your connection is no longer timing out, in my mind, the only thing I can think of that is cutting of your connection is a hardware or driver/firmware/software issue. Maybe a software re-install for your network equip?

As an anecdote, if you are opening up 2 GB files, it may behoove you to to use XSAN functionality or some sort of server software depending on the files you are opening. Long story short, AFP and SMB being simple file sharing and they (in my opinion) don't manage traffic and usage paticularly well like actual server software (outside of OS X Server) can.

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Answer 12

Aug 9, 2013 9:28 AM in response to Bryan Navarro

Hi Bryan -

First, thank you for taking the time to respond. The answer to your 2 questions is yes and no, respectively. I've already been on the phone with enterprise support with Apple several times and there is definitely a "known issue" regarding the transfer of large files, and large numbers of files over SMB with mountain lion. The SessTimeout tip definitely helped with the file copy issue, but didn't fix the issue I had of keeping large numbers of files open over the network. With my Windows Home Server, I can open a project with thousands of files in my DAW (digital audio workstation) over the network. But with the files residing on the OS X server, they open but then after several minutes, they literally go offline and "disappear". It's very frustrating. I should state that I did buy and install Dave 10 and that fixed the problem, so the problem is definitely on the Apple OS side, I was just hoping that this workaround with the SessTimeout would allow me to go back to Apple's SMB implementation. It just "feels" better to use the Server's implementation rather than a 3rd party app on top of it. Plus, it should just work. Maybe Mavericks will fix it. Maybe.

Just thought you might have another clever workaround that might make this work. At least with this workaround I can save Word and Excel files to the network without it taking 60 seconds.

any thoughts are greatly appreciated.

Charles.

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Answer 13

Aug 9, 2013 9:38 AM in response to Charlesdem

another interesting note - and maybe someone out there can test this for me. When I open a 15mb pdf file from the server on my client machine and keep it open for more than 5 or so minutes, it also suddenly goes offline and the content disappears.

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Answer 14

Aug 9, 2013 9:45 AM in response to Charlesdem

The difference between our situations is that I never had any issues over SMB from Mac to OS X Server. It was only from the PC side. That being the case, with yours not working Mac to Mac Server via SMB, I've gotta think there is something else at play here, software wise. Espeically if a Plug-in corrects the issue.

I hate to say this, but have you tried doing a full wipe and clean install? My hardware setup is the same as the OP but I've since updated the software to the current revisions. Even when the PCs were timing out, my Macs were all able to use SMB just fine, hence me being able to whittle it down to PC settings. Since the common denominator here is that every computer (Mac or PC) fail over SMB to OS X Server, I'm thinking it's either your Samba installation on the server or something along those lines.

Is there anything in your logs that point to specific errors or events? I'm not a very advanced user but I would try watching the logs as you force the issue to see what you find.

If there is any hope, it's gonna be in Mavericks updates as they are moving everything over to SMB for defaults so I'm sure they will verify things work correctly. One would hope.

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Answer 15

Aug 9, 2013 9:52 AM in response to Bryan Navarro

thanks Bryan. I never use SMB over macs. I just did it once to test when I was on the phone with Apple.

Mavericks is moving to SMB as opposed to AFP??

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