Offline Files Stay Disconnected Over Wi-Fi

miqrogroove
2016-03-15T14:15:29+00:00

Configure Slow Link ModeEver since my move to a new apartment, I was frustrated by some of my network files going offline randomly and staying offline for 5 minutes or up to an hour or two.  The weirdest part was that it would only happen to the network files that were in a path with Offline Files enabled.  As a result, I would periodically lose access to files that were not marked “Always available offline”, and I would get frequent synchronization conflicts for any files that were still available offline.

Another symptom of this problem was that I could map a separate drive letter to the same or deeper path, not enable Offline Files for the networked drive, and then have no trouble with the files when I try to use the drive letter.  I could even browse shared folders using the server’s UNC path at the same time as my Offline Files cache seemed to be stuck offline.

I had several suspicions about why this was happening.  First of all, I had started using Wi-Fi networking on my desktop computer as a convenience until I could knock some holes in the apartment walls to run proper Ethernet cables.  The signal quality seemed good enough that I shouldn’t have persistent connection problems, yet the Offline Files system seemed central to the problem.  I eventually discovered that the Client Side Cache “slow link” mode was at fault for this whole mess.

To find the culprit, it is necessary to drill deep into the Windows Event Viewer console tree.  Look in this path:

Event Viewer (Local) \ Applications and Services \ Microsoft \ Windows \ Offline Files \ Operational

Event ID 1004 is a huge red flag in this situation, and looks like this:

Log Name: Microsoft-Windows-OfflineFiles/Operational
Source: Microsoft-Windows-OfflineFiles
Date: 1/11/2016 10:51:58 AM
Event ID: 1004
Task Category: None
Level: Information
Keywords: Online/offline transitions
Description:
Path \\server\Folder transitioned to slow link with latency = 35 and bandwidth = 66871336

The key here is “latency.”  The offline files client, my desktop computer, detected a Wi-Fi ping delay of 35 ms and decided to shut down my connection to the server.  Now, 35 ms is not exactly an eternity in computing or networking, and it is an entirely normal result of transient radio interference in an apartment building.  The 67 Mbps of available bandwidth is also more than adequate.  So why is this causing so much trouble, and how do I fix it?

This event is also coupled with a much more generic message:

Log Name: Microsoft-Windows-OfflineFiles/Operational
Source: Microsoft-Windows-OfflineFiles
Date: 1/11/2016 10:51:58 AM
Event ID: 9
Task Category: None
Level: Information
Keywords: Online/offline transitions
User: SYSTEM
Description:
Path disconnected.
\\server\Folder

My research into this issue found many suggested solutions online, and all of them actually seemed wrong to me.

All I had to do was adjust the latency threshold to 100 ms and this whole problem went away!

Here are the steps I used:

  1. Open the server’s Default Domain Policy GPO.
  2. Navigate the console tree to Computer Configuration \ Policies \ Administrative Templates \ Network \ Offline Files \ Configure slow-link mode
  3. Change the setting to “Enabled”.
  4. Scroll to the bottom of the Options text box.
  5. Click the UNC Paths button titled “Show…”
  6. In the top row of the “Value name” column, type a single asterisk, “*”.  This is a wildcard name for all UNC paths.
  7. In the top row of the “Value” column, type “Latency=100”
  8. Click “OK” twice.
  9. On the client computer, execute “gpupdate /Target:Computer /Boot” from the command prompt.
15 Mar 2016

Category:
Systems Engineering

Tags:
, ,

Discuss:
Comments Go Here

Write a Comment