Applicable Products
- HDP for Business
- Proxmox VE
Scenario
You back up a Proxmox virtual machine that is in the Stopped state. When the backup starts, the Proxmox VE task log records a Start task for that virtual machine, issued by the user account that HDP for Business uses to connect to the host. It appears that the backup has powered on a virtual machine that you deliberately kept shut down.
Explanation
HDP for Business does not boot the guest operating system of a stopped virtual machine. To back up a stopped virtual machine, it places the virtual machine in prelaunch mode. In this mode, the QEMU process is created, but the guest operating system does not start and the virtual machine does not even reach its BIOS.
Prelaunch mode is required so that HDP for Business can use the QEMU Machine Protocol (QMP) to:
- Read the disk configuration and layout of the virtual machine.
- Read the Changed Block Tracking (CBT) data that identifies which disk blocks have changed since the previous backup.
Without this information, the virtual machine cannot be backed up consistently. Proxmox VE records the transition into prelaunch mode as a Start task, which is why the task appears in the task log even though the guest operating system never runs.
Details
- The guest operating system does not boot. The virtual machine does not reach its BIOS, and no application inside the guest is started.
- No network service of the virtual machine becomes reachable during the backup.
- After the backup finishes, the virtual machine returns to the power state it was in before the backup. A virtual machine that was stopped remains stopped, and a virtual machine that was running remains running.
- The Start entry in the Proxmox VE task log is expected behavior and does not indicate an unexpected power on.
- This behavior applies to backups triggered manually and to backups triggered by a schedule or an auto protection rule.
Further Reading
适用产品
- HDP for Business
- Proxmox VE
场景
您备份处于已停止状态的 Proxmox 虚拟机。当备份开始时，Proxmox VE 任务日志记录了由 HDP for Business 用于连接主机的用户账户发起的该虚拟机的启动任务。看起来备份启动了一个您故意保持关闭的虚拟机。
解释
HDP for Business 不会启动已停止虚拟机的客户操作系统。为了备份已停止的虚拟机，它将虚拟机置于预启动模式。在此模式下，创建了 QEMU 进程，但客户操作系统不会启动，虚拟机甚至不会进入其 BIOS。
预启动模式是必要的，以便 HDP for Business 可以使用 QEMU 机器协议（QMP）来：
- 读取虚拟机的磁盘配置和布局。
- 读取更改块跟踪（CBT）数据，该数据标识自上次备份以来哪些磁盘块发生了变化。
没有这些信息，虚拟机无法一致地备份。Proxmox VE 将进入预启动模式的转换记录为启动任务，这就是为什么即使客户操作系统从未运行，任务仍会出现在任务日志中。
详细信息
- 客户操作系统不会启动。虚拟机不会进入其 BIOS，客户内部的任何应用程序都不会启动。
- 在备份期间，虚拟机的任何网络服务都不可访问。
- 备份完成后，虚拟机返回到备份前的电源状态。已停止的虚拟机保持停止状态，正在运行的虚拟机保持运行状态。
- Proxmox VE 任务日志中的启动条目是预期行为，并不表示意外的启动。
- 此行为适用于手动触发的备份以及由计划或自动保护规则触发的备份。
进一步阅读
