What is the reason for the disconnection of access to the network folder (shares) on Windows Server 2012 r2?

Дмитрий Паршин 96 Reputation points

Colleagues, hello!

Сhaotically at different intervals of working hours access to network folders via smb is lost. The server is accessible via rdp and ICMP.


Hypervisor based on Windows Server 2012 r2 with the latest updates.

E5-2650v4 -2pcs, 128 GB Memory, Raid 5 7200.

The virtual machine is Windows Server 2012 r2 with the latest updates.

Cpu 2 core 10k memory

We have been struggling with the problem for more than 3 months, then the chronology:

1) The VM was originally based on 2008 r2 and we started getting similar problems. Since we are gradually transferring other services to 2012 r2 and we could not quickly find the cause of the problem, we decided to transfer the VM to 2012 r2.

  • The new VM was installed from an MSDN image
  • Fully updated
  • The disk from the old VM with the data share was disconnected, converted to VHDX, connected and network shares were thrown through the registry.

The machine worked fine for several days, but the problem recurred.

2) The volume of the data disk was 1300 GB. We decided to split it into two pieces and see what happens to the service.

  • The disk was connected and 700 GB of data was moved to it.
  • Migrated to manually shares folders.

Issues persisted, but the following behavior was recorded:

Access to only part of network folders is lost. When you open the explorer, 1 of the disks disappears.

3) We decided to re-transfer the data to new disks. But already remake NTFS rights on folders and get rid of the disk that was previously converted.

The problem remained, but we found a similar article from 2012 with more than 300 entries on the stream:



  • The forum suggested a method for overloading the "Server" service - the service goes into the "stop" status and hangs.
  • The UDP Arcserver backup system was disabled, but the problem persisted after the backup was disabled.
  • Moved the machine to another server with different hardware (C Supermicro - on HP 380g7)
  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\lanmanserver\parameters /v DisableLeasing /t REG_DWORD /d 1 /f
  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Servic es\lanmanserver\parameters /v MaxThreadsPerQueue /t REG_DWORD /d 1024 /f

5) Since everything suggested from the forum did not help us, we began to analyze the sessions that were open at the time of the hangup.

It was suggested that we have 3 problematic services on the file share:

  • Linker Server with 2014 SQL
  • Base MSACCESS 2003
  • And some folder with huge paths

First of all, we decided to move the MSACCESS databases from one disk to another and got the following situation:

Earlier, we lost drive E, after the transfer, drive F began to disappear

6) We moved the access bases to another server and after 4 days of stable work we got errors again.
But now, when the problem appeared, broken files were fixed:

  • xlsx document the employee worked with
  • pdf document that was saved to the network share.

We are in the stage of shock and do not understand what we can catch on to.

Windows Server 2012
Windows Server 2012
A Microsoft server operating system that supports enterprise-level management, data storage, applications, and communications.
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Windows Server
Windows Server
A family of Microsoft server operating systems that support enterprise-level management, data storage, applications, and communications.
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2 additional answers

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  1. Dave Patrick 426.1K Reputation points MVP

    I'd suggest starting a case here with product support.

    --please don't forget to Accept as answer if the reply is helpful--

    0 comments No comments

  2. Candy Luo 12,646 Reputation points Microsoft Vendor

    Hi ,

    Since your environment is complex, I would suggest you open a case with Microsoft where more in-depth investigation can be done so that you would get a more satisfying explanation and solution to this issue.

    Also, in this way, they can have a clear picture about your issue and your environment by phone communication and live share session.

    You may find phone number for your region accordingly from the link below:

    Global Customer Service phone numbers

    Best Regards,



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