Help Center> Huawei Cloud Flexus> Service Overview> FlexusX> Notes and Constraints on Using FlexusX Instances
Updated on 2024-06-17 GMT+08:00

Notes and Constraints on Using FlexusX Instances

To ensure that your FlexusX instances run properly, read the following notes and constraints before using them.

General Constraints

  • Private images are regional resources. FlexusX instances only can use private images that are in the same region as them.
  • FlexusX instances use the x86 architecture and do not support private images created using Arm servers.
  • FlexusX instances do not support nested virtualization.
  • Do not install external hardware devices, such as encryption dongles or USB flash drives on FlexusX instances.

Precautions

When using FlexusX instances, comply with the precautions listed below.

  • Do not use FlexusX instances as unauthorized servers for any illegal or violation service, such as gambling or cross-border VPN.
  • Do not use FlexusX instances for fraudulent transactions, such as click farming on e-commerce websites.
  • Do not use FlexusX instances to initiate network attacks, such as DDoS attacks, CC attacks, web attacks, brute force cracking, or spreading of viruses and Trojan horses.
  • Do not use FlexusX instances for traffic transit.
  • Do not use FlexusX instances for web crawling.
  • Do not use FlexusX instances to detect other systems like scanning or penetration unless otherwise being authorized.
  • Do not deploy any illegal websites or applications on FlexusX instances.
  • Do not uninstall drivers from the hardware of FlexusX instances.
  • Do not change the MAC address of NICs.
  • The authentication mechanism of certain software may require that software licenses be associated with the physical server hosting FlexusX instances. Once a FlexusX instance is migrated from one physical server to another, the associated licenses may become invalid.
  • A FlexusX instance may need to stop or restart when it is migrated from a faulty host. For high service availability, deploy applications in a cluster or on FlexusX instances working in active/standby mode, or configure automatic startup upon a host failure or startup.
  • Back up data for FlexusX instances where core applications are deployed.
  • Monitor application metrics on FlexusX instances.
  • Do not change the default DNS server address. If you need to configure a public DNS server address, configure both a public and a private DNS address for your FlexusX instance.
  • Do not stop system processes if you are not sure about the consequences. Otherwise, blue screen of death (BSOD) or a restart may occur on FlexusX instances.
  • Ensure that there is at least 2 GiB of idle memory. Otherwise, BSOD, freezing, or service failures may occur.
  • Do not modify the registry. Otherwise, the system startup may fail. If the modification is mandatory, back up the registry before modifying it.
  • Do not modify the clock settings. Otherwise, DHCP lease may fail, leading to the loss of IP addresses.
  • Do not delete the CloudResetPwdAgent or CloudResetPwdUpdateAgent process. Otherwise, one-click password reset will become unavailable.
  • Do not disable virtual memory. Otherwise, system performance may deteriorate, or system exceptions may occur.
  • Do not delete the VMTool program, or an exception may occur on FlexusX instances.
  • Do not modify the /etc/issue file. Otherwise, the OS distribution will not be identified.
  • Do not delete system directories or files. Otherwise, the system may fail to run or start.
  • Do not change the permissions for or names of system directories. Otherwise, the system may fail to run or start.
  • Do not upgrade the kernel of the Linux unless necessary.

    When you have to upgrade the Linux kernel, follow the instructions provided in How Can I Upgrade the Kernel of a Linux ECS?

  • Do not delete the CloudResetPwdAgent or CloudResetPwdUpdateAgent process. Otherwise, one-click password reset will become unavailable.
  • Do not change the default /etc/resolv.conf of the DNS server. Otherwise, software sources and NTP may be unavailable.
  • Do not modify default intranet configurations, such as the IP address, subnet mask, or gateway address of a FlexusX instance. Otherwise, network exceptions may occur.
  • Manually specified IP addresses for Linux FlexusX instances are generally static IP addresses. To avoid network exceptions caused by conflicts between NetworkManager and internal network services, do not enable NetworkManager when not required, such as when installing Kubernetes.