Windows Server · Windows  ·  high  ·  Roles & shared services

"The specified network name is no longer available"

The SMB session was torn down mid-operation. On a file server under load it is usually resource exhaustion; on a client it is usually the network path.

What you see

Copies fail part way through, applications lose their connection to a share, roaming profiles fail to save. Event 2017 on the server when it has run out of paged pool.

What is actually wrong

Server-side: the SMB server ran out of non-paged pool or session resources. Network-side: an offload feature, a flapping link, or a firewall dropping idle sessions.

Codes and articles

0x80070040ERROR_NETNAME_DELETEDspecified network name is no longer availableEvent 2017Event 30809

Fixes (2)

Raise the file server's SMB resource limits
Elevated PowerShell on the file server40 minutesmedium riskreversible

Several clients are affected by one server. Event 2017 confirms it.

  1. Look for the resource exhaustion event.

    PowerShell
    Get-WinEvent -FilterHashtable @{LogName='System'; Id=2017} -MaxEvents 10 -ErrorAction SilentlyContinue | Format-List TimeCreated, Message

  2. Check the current SMB server configuration.

    PowerShell
    Get-SmbServerConfiguration | Format-List MaxChannelPerSession, MaxSessionPerConnection, MaxThreadsPerQueue, AsynchronousCredits

  3. Raise the memory the SMB server may use for large requests.

    PowerShell
    Set-ItemProperty 'HKLM:\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters' -Name 'Size' -Value 3 -Type DWord

    Size=3 tunes the server for file sharing over other roles. It is the documented first move for 2017 and needs a restart.

  4. Raise the worker threads if the server has many concurrent clients.

    PowerShell
    Set-SmbServerConfiguration -MaxThreadsPerQueue 60 -Force

  5. Check the NIC's receive-side scaling is on so SMB traffic is spread across cores.

    PowerShell
    Get-NetAdapterRss | Format-Table Name, Enabled, NumberOfReceiveQueues -AutoSize

  6. Restart the server at a scheduled time — most of these settings need it.

Confirm it workedNo further 2017 events and copies complete.
PowerShell
Get-SmbServerConfiguration | Format-List MaxThreadsPerQueueGet-Counter '\Server\Work Item Shortages' -SampleInterval 5 -MaxSamples 3
If you need to undo itSet Size back to its previous value and MaxThreadsPerQueue to 20.
Rule out offloading and idle timeouts on the client path
Elevated PowerShell on the client30 minuteslow riskreversible

One machine is affected.

  1. Test the path holds up under a sustained transfer.

    PowerShell
    Test-NetConnection -ComputerName FS01 -Port 445 -InformationLevel Detailed

  2. Turn off the offload features that most often corrupt or drop long SMB transfers.

    PowerShell
    Disable-NetAdapterLso -Name '*'Set-NetOffloadGlobalSetting -Chimney DisabledSet-NetOffloadGlobalSetting -TaskOffload Disabled

    This is a diagnostic step, not a permanent configuration — offload exists for good reason. If disabling it fixes the problem, the answer is a NIC driver update, not leaving it off.

  3. Stop the session being closed while idle.

    PowerShell
    Set-SmbClientConfiguration -SessionTimeout 300 -Force

  4. Update the network driver from the machine vendor and re-enable offloading.

    PowerShell
    Enable-NetAdapterLso -Name '*'Set-NetOffloadGlobalSetting -TaskOffload Enabled

  5. Check for a firewall or IPS between the two dropping long-lived sessions.

Confirm it workedA large file copies end to end without failing.
If you need to undo itRe-enable the offload settings as in step 4.

Related faults

Gigabit LAN transfers run at a fraction of the speedWindowsA file is locked open by a user who has gone homeWindows Server0x80070035 — "the network path was not found" reaching a shareWindows

Where this stops. This write-up was written and checked by hand. It says what each step changes, how to confirm it worked and how to reverse it, and anything destructive is flagged before you reach it. If it does not match what your machine is doing, search the Support Centre for the exact code or message — and when something needs a person, get in touch.