Before you import images, we recommend that you read the following instructions to ensure image availability and improve import efficiency.

Windows Server images

When you import a Window Server image, take note of the following system-related items:

  • Verify the integrity of the file system.
  • Do not modify critical system files.
  • Make sure that the system disk has sufficient free space.
  • Configure the size of the system disk based on the size of the virtual disk rather than that of the image. The system disk can be 40 GiB to 500 GiB in size.
  • Disable the firewall.
  • Allow traffic on Remote Desktop Protocol (RDP) port 3389.
  • Make sure that the logon password for the administrator account meets the password complexity requirements. The password must be 8 to 30 characters in length and must contain at least three of the following character types: uppercase letters, lowercase letters, digits, and special characters. Special characters include ( ) ` ~ ! @ # $ % ^ & * - _ + = | { } [ ] : ; ' < > , . ? /. The password cannot start with a forward slash (/).

The following items are not supported:

  • Optical disc images (ISO images). Before you import ISO images to Elastic Compute Service (ECS), you must use tools such as VirtualBox to convert the images to the RAW, VHD, or QCOW2 format on your computer.
  • Installation of the QEMU guest agent (GA) in images. If the QEMU GA is installed, some services that ECS requires may be unavailable.
  • Images that run the following operating system versions:
    • Windows XP
    • Windows 8
    • Windows 8.1
    • Windows 10
  • Installation of a Community Edition virtio driver in Windows Server operating systems. If a Community Edition virtio driver is installed, remove the read-only property of the following files:
    • C:\Windows\System32\drivers\netkvm.sys
    • C:\Windows\System32\drivers\balloon.sys
    • C:\Windows\System32\drivers\vioser.sys
    • C:\Windows\System32\drivers\viostor.sys
    • C:\Windows\System32\drivers\pvpanic.sys

The following items are supported:

  • Multi-partition system disks.
  • Master boot record (MBR) and GUID Partition Table (GPT) partitions as well as New Technology File System (NTFS) file systems.
  • Images in the RAW, QCOW2, or VHD format. If the image that you want to import is not in one of the preceding formats, you must convert the image to a supported format before you can import the image. For more information, see Convert the image file format.
  • Images that run the following operating system versions:
    • Microsoft Windows Server 2019
    • Microsoft Windows Server 2016
    • Microsoft Windows Server 2012 R2
    • Microsoft Windows Server 2012
    • Microsoft Windows Server 2008 R2
    • Microsoft Windows Server 2008
    • Windows Server 2003 Service Pack 1 or later

Linux images

When you import a Linux image, take note of the following system-related items:

  • Verify the integrity of the file system.
  • Do not modify critical system files such as files located under/sbin, /bin, and /lib* directories.
    • Do not modify /etc/issue*. Otherwise, the distribution of the operating system cannot be identified by ECS and the instance operating system cannot be created.
    • Do not modify /boot/grub/menu.lst. Otherwise, the ECS instance cannot be started.
    • Do not modify /etc/fstab. Otherwise, abnormal partitions cannot be loaded and the ECS instance cannot be started.
    • Do not set /etc/shadow to read-only. Otherwise, the password file cannot be modified and the instance operating system cannot be created.
    • Do not modify /etc/selinux/config to enable SELinux. Otherwise, the instance operating system cannot be started. If you must enable SELinux, see Enable or disable SELinux.
  • Make sure that the system disk has sufficient free space.
  • Disable the firewall.
  • Allow traffic on SSH port 22.
  • Enable Dynamic Host Configuration Protocol (DHCP).
  • Install the XEN or Kernel-based Virtual Machine (KVM) driver. For more information, see Install the virtio driver.
  • Install cloud-init to configure the hostname, NTP repositories, and YUM repositories. For more information, see Install cloud-init.
  • Make sure that the logon password for the root account meets the password complexity requirements. The password must be 8 to 30 characters in length and must contain three of the following character types: lowercase letters, uppercase letters, digits, and special characters. Special characters include ( ) ` ~ ! @ # $ % ^ & * - _ + = | { } [ ] : ; ' < > , . ? /.

The following items are not supported:

  • Optical disc images (ISO images). Before you import ISO images to Elastic Compute Service (ECS), you must use tools such as VirtualBox to convert the images to the RAW, VHD, or QCOW2 format on your computer.
  • Multiple network interfaces.
  • IPv6 addresses.
  • Adjustment of system disk partitions. Only disks with a single root partition are supported.
  • Installation of the QEMU GA in images. If the QEMU GA is installed, some services that ECS requires may be unavailable.
  • Creation of system partitions (the root partitions) across disks by using Logical Volume Manager (LVM), which makes ECS instances fail to start.

The following items are supported:

  • Images in the RAW, QCOW2, or VHD format. If the image that you want to import is not in one of the preceding formats, you must convert the image to a supported format before you can import the image. For more information, see Convert the image file format.
  • MBR and GPT partitions as well as XFS, ext3, and ext4 file systems.
  • However, the ext4 file system cannot contain the 64bit feature, and the project and quota features cannot be used together. You can run the following command to view the list of features contained in the ext4 file system:
    tune2fs -l <ext4 file system disk directory> | grep features
  • Images that run the following operating system versions:
    • Alibaba Cloud Linux
    • CentOS 5/6/7/8
    • Debian 6/7/8/9/10
    • FreeBSD
    • OpenSUSE 13/42/15
    • RedHat
    • Red Hat Enterprise Linux (RHEL)
    • SUSE Linux 10/11/12/15
    • Ubuntu 10/12/13/14/16/18/20
    • CoreOS 681.2.0+

Non-standard Linux images

Linux images that are not listed as ECS public images are considered as non-standard images. Such images are developed on a standard operating system platform, but none of their critical system configuration files, basic system environments, or applications comply with the standard operating system requirements of ECS. If you want to use a non-standard platform image, select one of the following image types and perform corresponding operations:

  • Others Linux: ECS identifies all images of this type as other Linux systems. If you import an Others Linux image and then use it to create instances, ECS does not process the created instances. If DHCP is disabled in the Others Linux image, you must connect to the instances by using the remote connection feature in the ECS console and then manually configure IP addresses, routes, and passwords for the instances. If DHCP is enabled in the Others Linux image, networks are automatically configured for the instances when you log on to the instances.
  • Customized Linux: After a customized Linux image is imported, you can create instances from this image and configure networks and passwords for the instances in the same manner as you would with instances created from standard ECS images. For more information, see Customize Linux images.