Hello,
I would ask how many databases can be backed up using VSS at the same time.
Of course, it depends on the SQL version and the server resources.
I know that the max worker threads has to be increased. There are some recommendations from https://msdn.microsoft.com/en-us/library/ms190219%28v=sql.120%29.aspx
I set it to 1426 and it worked.
Also an article from 2013 mentioned the following...
"...
With the current SQL Server design, it is recommended to configure a minimal number of databases on a given volume. When a large numbers of databases on the same volume cannot be avoided, VSS backups are not advised (use legacy backups instead). If SQL
is 64-bit, it may be helpful to increase the max worker thread setting when performing VSS backups.
Microsoft is currently considering a design change for future versions of SQL Server.
Microsoft support should be contacted for any additional information on this issue. "
Are those remarks still valid with the SQL Server 2016 and 2014 ?
In particular, my server is a x64 Windows 2012 R2 Datacenter, SQL Server 2014 with SP2 and CU2.
Resources are 2 CPU's Intel64 Family 6 Model 46 Stepping 6 GenuineIntel ~2261 Mhz, 16 GB of RAM, data disk 300 GB, logs on other volume of 16 GB.