Available image check items-Server Migration Center(SMC)-阿里云帮助中心

The image check feature identifies potential issues in a custom image after import, ensures the image meets Alibaba Cloud standards, and improves the success rate of launching ECS instances.

Linux check items

The following table lists the check items and recommended solutions for Linux images.

Check item	Description	Recommended solution
GUESTOS.Platform	Verifies that the operating system is Linux.	N/A
GUESTOS.OSVersion	Verifies the operating system version. Example: CentOS 7.9.	N/A
GUESTOS.Architecture	Verifies the system architecture. Examples: x86_64, arm64, and i386.	N/A
GUESTOS.RtcTimeMode	Verifies the Real-Time Clock (RTC) time standard, which can be UTC or local. UTC is recommended.	For more information about how to set the RTC time standard to UTC, see Linux time and time zones.
GUESTOS.BootMode	Verifies the image boot mode, which can be LEGACY or UEFI.	N/A
GUESTOS.KernelVersion	Verifies the kernel version. Example: 3.10.0-1160.21.1.el7.x86_64.	N/A
GUESTOS.Virtio	The virtio driver is required for virtualization. A missing driver can cause the ECS instance to fail to start.	For more information about how to install the virtio driver, see Install the virtio driver.
GUESTOS.Nvme	Verifies that the NVMe driver is installed. This driver is required for certain instance families, such as ecs.g7se, that use NVMe-based cloud disks.	For more information about how to install the NVMe driver, see Install the NVMe driver on a custom image.
GUESTOS.Fstab	Verifies the system disk mount configurations in the `/etc/fstab` file. Incorrect configurations, such as a non-existent mount device or an incorrect device UUID, can cause the system to fail to start.	For more information about how to correctly configure the `/etc/fstab` file, see Use UUIDs to automatically mount data disks in the fstab file.
GUESTOS.Grub	Verifies the GRUB bootloader file configuration. Issues such as an improperly configured device, a non-existent device, or an incorrect UUID can cause the system to fail to start.	For more information about how to generate a correctly configured GRUB file, see Modify the disk partition identifier to UUID in the GRUB configuration file.
GUESTOS.Selinux	Verifies that SELinux is disabled. SELinux can cause cloud images to fail to start and is not recommended.	For more information about how to disable SELinux, see Enable or disable SELinux.
GUESTOS.OnlineResizeFS	Verifies that the image supports automatic root partition resizing. If tools like `cloud-init` and `growpart` are installed, the root partition automatically resizes to match the system disk size when an instance is created from the image. For example, if you create an instance with a 100 GB system disk from a 20 GB image, the root partition automatically expands to 100 GB.	For more information about how to configure an image to support auto scaling, see Install cloud-init.
GUESTOS.SystemImage	Verifies that the imported file is a valid system disk image, not an ISO file or an empty image.	N/A
GUESTOS.CloudInit	Verifies that cloud-init is installed. cloud-init is an industry-standard tool for initializing cloud instances, handling tasks such as setting the hostname, adding public keys, and resizing the root partition.	For more information about how to install cloud-init, see Install cloud-init.
GUESTOS.SupportMocInstanceTypes	Verifies that the image supports SHENLONG instance types. Many recent Alibaba Cloud ECS instances, such as ecs.g6 and ecs.g7, are SHENLONG instance types. Outdated OS or kernel versions can prevent these instance types from starting. For more information about instance specifications, see instance family.	If you are using CentOS 5, we recommend that you upgrade to the latest version, CentOS 5.11. For more information, see How do I resolve instance downtime after migration?. Operating systems that do not support SHENLONG instance types are typically older, end-of-life (EOL) versions. We recommend that you upgrade to a currently supported OS version from your vendor.

Windows check items

The following table lists the check items and recommended solutions for Windows images.

Check item	Description	Recommended solution
GUESTOS.Platform	Verifies that the operating system platform is Windows.	N/A
GUESTOS.OSVersion	Verifies the operating system version. Example: Windows Server 2016 Datacenter.	N/A
GUESTOS.Architecture	Verifies the system architecture. Example: amd64.	N/A
GUESTOS.KernelVersion	Verifies the kernel version.	N/A
GUESTOS.BCD	Verifies the Boot Configuration Data (BCD) file in the image. A missing or corrupted BCD file can prevent the instance from starting.	Use a valid BCD file.
GUESTOS.Registry	Verifies the registry file in the image. A missing or corrupted registry file can prevent the instance from starting.	Use a valid registry file.
GUESTOS.Hotfix	Verifies that the correct patches are installed. Missing required patches or installing problematic ones can prevent the instance from starting.	Uninstall problematic patches. This includes: KB5009624, KB5009595, KB5009546, KB5009557, KB5009555, KB5014738, KB5014702, KB5014692, and KB5014678. For Microsoft Windows Server 2008 R2 64-bit operating systems, patch KB3033929 is also required.
GUESTOS.Disk	Verifies the disk settings in the image. Residual driver entries on the disk can prevent the instance from starting.	Clear residual drivers from the registry
GUESTOS.Sysprep	Verifies that the Sysprep process was completed before migration. Migrating before Sysprep finishes can prevent the system from starting correctly.	Do not migrate while the Sysprep process is running.
GUESTOS.Update	Verifies that any pending update processes were completed before the image was created. Creating an image while an update is in progress can prevent the system from starting correctly.	Ensure all update processes are complete before creating the image.
GUESTOS.Xen	Verifies that no residual Xen drivers are present. Residual Xen drivers can prevent the system from starting correctly.	Disable the Xen driver
GUESTOS.Server	Verifies that service configurations allow automatic driver installation. If settings block driver installation, required drivers cannot be updated on the instance.	Allow drivers to be installed
GUESTOS.DesktopConfig	Verifies that the desktop configuration file (`desktop.ini`) is present. If this file is missing, desktop configurations will not be applied.	Ensure the `desktop.ini` file is configured correctly.
GUESTOS.BootMgr	Verifies that the Windows Boot Manager (BootMgr) is present. A missing BootMgr will prevent the system from starting.	Ensure BootMgr is configured correctly.