To guarantee proper operation of your ECS instance, you must take the considerations outlined in this section into account before use.

Prohibitions
  • Alibaba Cloud prohibits you from using your instance for flow-through services.  Any violation results in punishment up to shutdown and lockout of instance, and termination of services.
  • Alibaba Cloud prohibits you from using your instance for click farming, advertising, or fictitious transactions.
  • Alibaba Cloud prohibits you from activating SELinux.
  • Alibaba Cloud prohibits you from uninstalling hardware related drivers.
  • Alibaba Cloud prohibits you from arbitrarily modifying the MAC address of the network adapter.
Suggestions
  • For an ECS with more than 4 GiB RAM, we recommend that you use a 64-bit OS, because a 32-bit OS supports a maximum of 4 GiB RAM. Currently available 64-bit systems include:
    • Aliyun Linux
    • CoreOS
    • CentOS
    • Debian
    • FreeBSD
    • OpenSUSE
    • SUSE Linux
    • Ubuntu
    • Windows
  • 32-bit Windows OS supports CPUs with up to 4 cores.
  • A minimum of 2 GiB RAM is needed for buiding a website on a Windows instance, and an instance type with 1 vCPU core and 1 GiB RAM cannot be used for MySQL service.
  • To guarantee service continuity and avoid service downtime, you must enable auto-start of service applications upon OS boot.
  • For I/O-optimized instances, do not stop the aliyun-service process.
  • We do not recommmend that you update the kernel and the OS. For more information, see How to avoid Linux instance startup failure after kernel upgrade.

Windows restrictions

  • Do not close the built-in shutdownmon.exe process, which may delay the restart of your Windows server.
  • Do not rename, delete, or disable the Administrator account.
  • We do not recommend that you use virtual memory.

Linux restrictions

  • Do not modify the content of the default /etc/issue file. Otherwise, if you create a custom image of the ECS instance and create a new ECS instance based on the image, the new instance cannot start because the operating system edition cannot be recognized.
  • Proceed with caution when modifying permissions of the directories in the root partition, such as /etc, /sbin, /bin, /boot, /dev, /usr and /lib. Improper modification of permissions may cause errors. Such modifications may cause system errors.
  • Do not rename, delete, or disable the Linux root account.
  • Do not compile or perform any other operations on the Linux kernel.
  • We do not recommend that you use swap partition.
  • Do not enable the NetWorkManager service. This service conflicts with the internal network service of the system and causes network errors.

For more information, see Limits.