Technical guide on VPS power controls within SolusVM 2. Understand the difference between graceful ACPI shutdowns and hardware-level Force Stop operations to prevent data corruption.

Power Management Controls: ACPI Shutdown vs. Force Stop Operations

Managing the power state of your Virtual Private Server (VPS) through the SolusVM 2 dashboard (vm.hovixa.com) involves two distinct methods of termination. Choosing the correct operation is critical for maintaining filesystem integrity and ensuring that database transactions are safely committed to the NVMe storage.

1. ACPI Shutdown (The Graceful Method)

An ACPI Shutdown sends a standardized signal to the guest Operating System's power management daemon. It is the virtual equivalent of pressing the power button on a physical server once.

Technical Workflow:

1. The hypervisor sends an ACPI power button press event to the VM.
2. The OS initiates its shutdown sequence (e.g., systemd or init).
3. Active processes receive a SIGTERM signal to close safely.
4. Filesystems are unmounted, and buffers are flushed to disk.
5. The VM powers off once the OS confirms it is safe.

Use Case: Standard maintenance, resizing resources, or preparing for a planned offline window.

2. Force Stop (The Hard Power-Off)

A Force Stop (or "Power Off") immediately terminates the KVM process on the host node. This is the virtual equivalent of pulling the power cable out of a physical server.

[Image showing the risk of data corruption when a hard stop occurs during a database write]

Technical Workflow:

1. The hypervisor kills the virtual machine process instantly.
2. The guest OS has no opportunity to sync data or unmount filesystems.
3. Unwritten data in the RAM cache is lost.

Use Case: Only use this if the guest OS is completely unresponsive, the kernel has panicked, or an ACPI Shutdown has failed to execute after several minutes.

3. Comparison Table

4. Troubleshooting "Soft" Power Failures

• ACPI Not Responding: If the ACPI Shutdown button does nothing, your Linux template may be missing the necessary drivers. You can usually fix this by running apt install acpid or yum install acpid and enabling the service.
• Stuck Reboots: If a Reboot command hangs, it is often due to a process (like a hanging network mount or a heavy database) refusing to terminate. In these specific cases, a Force Stop followed by a Start is the only recovery path.

5. Technical Implementation Details

• KVM signal: Under the hood, ACPI Shutdown uses the virsh shutdown command, while Force Stop uses virsh destroy.
• Hardware Clock: Neither operation affects your system time settings, as these are synchronized with the host node's hardware clock (RTC).
• Snapshots: Never perform a power operation while a Snapshot is in progress. Wait for the task to reach 100% completion in the SolusVM 2 task log.

Sysadmin Advice: Always attempt an ACPI Shutdown first. If the VM is still "Running" after 120 seconds, only then proceed to a Force Stop. This discipline prevents 99% of filesystem-related boot failures.