Scale-Out File Server (SoFS) SMB Session Resiliency Failover Failure

Hi @Vincent Keung Koh

For a Scale-Out File Server (SoFS), enable Continuous Availability (CA) on the SMB shares for SMB Transparent Failover. Continuously available shares allow supported SMB clients to reconnect transparently to another cluster node following planned maintenance or an unexpected node failure.

You can verify the setting from PowerShell on the file server cluster:

Get-SmbShare | Select-Object Name, ScopeName, Path, ContinuouslyAvailable

Or check a specific share:

Get-SmbShare -Name "<ShareName>" |
    Select-Object Name, ScopeName, ContinuouslyAvailable

For a properly configured SoFS share, you should see:

ContinuouslyAvailable : True

Get-SmbShare exposes ContinuouslyAvailable specifically for this purpose.

If it is False, you can enable CA on an existing SMB share with:

Set-SmbShare -Name "<ShareName>" -ContinuouslyAvailable $true -Force

Then verify it again:

Get-SmbShare -Name "<ShareName>" |
    Select-Object Name, ContinuouslyAvailable

Set-SmbShare supports the -ContinuouslyAvailable property for modifying an SMB share.

I would also verify that this is actually a Scale-Out File Server share hosted on a Cluster Shared Volume (CSV). Continuous Availability alone doesn't provide transparent failover if the underlying SoFS/cluster configuration isn't correct. Microsoft's requirements for SMB Transparent Failover include a supported failover cluster, CA-enabled shares, CSV-backed shares for SMB Scale-Out, and supported SMB clients.

You can also check active client connections:

Get-SmbConnection |
    Select-Object ServerName, ShareName, Dialect, ContinuouslyAvailable

For modern SoFS clients, you would normally expect SMB 3.x and ContinuouslyAvailable = True.

If CA is already enabled but clients still disconnect during an unexpected node failure, I would then investigate SMB client/server event logs, cluster events, CSV health, SMB Multichannel/network paths, and the application workload, rather than changing the share again.

One point worth noting: Microsoft states that Continuous Availability is the default for these clustered file shares, so if existing SoFS shares show False, I would also check how those shares were originally created or whether their configuration was modified afterward.

Sharing these references with you:

SMB features in Windows and Windows Server – SMB Transparent Failover

Scale-Out File Server overview

Get-SmbShare

Set-SmbShare

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