Veeam back up of a MSSQL DB server throws the following error (some content changed):
Error: Client error: File does not exist or locked. VMFS path: [datastorename] servername/serverfile.vmx Please, try to download specified file using connection to the ESX server where the VM registered. Failed to create NFC download stream. NFC path: [nfc://conn:192.x.y.z,nfchost:hostname,stg:datastore@servername/serverfile.vmx]
A reboot of the server does not help.
A shutdown of the server and the running of the Veeam backup works but that means the DB server has to be down during that time.
Simple solution that works:
Go to services (services.msc), stop Veeam services
Download Veeam v9 and run the upgrade
Rerun backup job with no changes
If your issue is not Veeam related, check out this KB from VMWare: link to VMWare
VMWare Esxi 6.0
Veeam Backup and Replication v8
Veeam Backup and Replication v9
VCenter Appliance 6.0
MS SQL 2012 Server Standard