Slow and Problematic Windows -> Linux SMB Share

Slow and Problematic Windows -> Linux SMB Share

Like many people, I have a Synology NAS that I use for backups. I backed up various Windows Servers to a Share on this NAS overnight using tools including Veeam, but it kept failing but only intermittently. Yes, I know; the worst type of error is an intermittent error.

Each time I ran the backups manually, they seemed to run fine. That was until they didn’t run, and I received the same error. Eventually, after looking through the Event Logs, it appeared to be an SMB failure. Armed with this additional, missing piece of information, I was able to determine that the problem was a simple timeout problem – the disks in the Synology system are just spinning rust, and the network connection in it is only 1Gb – and with the large amount of data being backed up each time, it was timing out.

The fix was surprisingly simple. On the Veeam Windows Backup server, I issued the following command in Powershell as an Administrator, and the problem vanished. The server has now been running for weeks without a hitch.

Set-SmbClientConfiguration -SessionTimeout 600


Hi, my name is Stephen Finchett. I have been a software engineer for over 30 years and worked on complex, business critical, multi-user systems for all of my career. For the last 15 years, I have been concentrating on web based solutions using the Microsoft Stack including ASP.Net, C#, TypeScript, SQL Server and running everything at scale within Kubernetes.