I've installed Veeam Endpoint Backup, and attempted to set it up to backup to various targets. No matter what I do, the backup stops a few seconds after starting with the error:
Error: Failed to create snapshot: Backup job failed. Cannot create a shadow copy of the volumes containing writer's data. VSS asynchronous operation is not completed. Operation: [Shadow copies commit]. Code: [0x8004230f]
Some Googling revealed that Endpoint can throw this error if a VSS writer has timed out, and the suggested solution is to use NET STOP and NET START with the writer name to restart the writer. However, I have writers with spaces in their names, and the NET command doesn't recognize them, even in quotes.
The bigger issue is that all my writers are "stable" before Endpoint starts a backup, and then 10 out of 15 writers immediately go to Failed/Timed Out when Endpoint tries to back up. The only way to reset them is to reboot the server, at which point Endpoint kills the writers again.
I asked Veeam support on Twitter about it, and they told me to "log a support call through the Endpoint UI." Veeam's support website essentially forces me to do the same thing. But, as I said, this server is on an air-gapped server which is not permitted to access the network. When I start to fill out the support dialog in the UI, predictably, it tells me it can't access the internet.
To answer some potential questions: We're not supposed to apply updates to this server beyond SP1; yes VSS is turned on, the error is the same with VSS turned on or turned off; the error is the same whether using the Administrator account or another account that is a member of the Administrators (or Backup Operators) group; I have tried the full system and full volume backup types, because that's what I need; I have tried setting my backup target both to an SMB share on another local server on the network and a USB-connected 4TB hard disk.
I had high hopes for Veeam Endpoint Backup, and perhaps moving to a paid solution in the future, but I'm not getting a really good customer service experience from Veeam. They seem more concerned with someone accidentally getting good service outside the UI. I guess if someone here can't get it working I'll need to look elsewhere for a backup solution.