斯科特，你好，

Hi Scott,

在大多数情况下，此问题是由虚拟机上运行的过时的代理引起的.您能否检查您是否正在运行代理的最新版本，并根据需要尝试按以下链接中的说明进行更新:

In most cases, this issue is caused by an outdated Agent running on your Virtual Machine. Can you please check if you are running the latest version of the agent and if needed try updating it as described in the link below:

https://docs.microsoft.com/zh-CN/azure/virtual-machines/extensions/update-linux-agent

https://docs.microsoft.com/en-us/azure/virtual-machines/extensions/update-linux-agent

清除存储在/var/lib/waagent/文件夹中的代理缓存.您可以通过运行以下命令来做到这一点:

Clear the Agents cache stored in the /var/lib/waagent/ folder. You can do it by running this command: 

sudo rm -f /var/lib/waagent/*.[0-9]*.xml

此外，请确保代理服务成功启动.如果问题仍然存在，请查看此文档，并查看列出的要点是否有帮助:https://docs.microsoft.com/en-gb/azure/backup/backup-azure-troubleshoot-vm-backup- failed-snapshot-timeout

Also, make sure that the Agent service starts successfully. If the issue persists, please have a look at this document and see if points listed are helpful: https://docs.microsoft.com/en-gb/azure/backup/backup-azure-troubleshoot-vm-backup-fails-snapshot-timeout