Edit a cloud host

Restrictions and guidelines

If you select a high-speed disk for a cloud host, the high-speed disk can be used after you update its driver.

If you add or delete a high-speed disk for a running cloud host, the operation takes effect immediately. If you add or delete other types of disks for the cloud host, the operation takes effect when the cloud host starts again.

When you delete a NIC from a running cloud host, the NIC is deleted immediately if the operating system of the cloud host supports online NIC deletion. The NIC is deleted on the next startup if the operating system of the cloud host does not support online NIC deletion.

If you delete the USB device on a host that contains a running cloud host configured with USB devices, that cloud host cannot access the USB device. To enable the cloud host to access the USB device, you must restart the cloud host.

After you mount an image file to the virtual drive and open the drive from the cloud host operating system, display failure might occur. To resolve this issue, eject the drive, and then re-mount the image file to the drive from the cloud host console or from the cloud host editing page.

As a best practice to change the bus type for the disk of a cloud host, shut down the cloud host without powering it off; delete the disk on the cloud host editing page, add a disk with the desired bus type, select the disk file (block device) of the deleted disk, and then start the cloud host.

Procedure

On the top navigation bar, click Resources.

From the left navigation pane, select Virtualization.

Click the Expand icon on the left of CloudOS, click the Expand icon on the left of a cluster, and then click the Expand icon on the left of a host.

Click the name of a cloud host.

Click Edit.

Click the tabs to edit the cloud host settings, and click Apply after you edit the settings on a tab.

Parameters

Parameter	Description
Alias	Enter an alias for the cloud host. Chinese characters are supported.
Auto Migration	Enable this feature to enable the cloud host to automatically migrate in the cluster after DRS takes effect.
HA	Enable or disable HA for the cloud host. If you disable HA for a cloud host, the cloud host will not be managed by cluster HA. This parameter is available only when the cluster is enabled with HA.
Time Sync	Enable or disable time synchronization between the cloud host and the host where the cloud host resides. After you enable this feature, the system time of the cloud host is automatically synchronized to the system time of the host when their system time is different.
CAStools Upgrade	Enable this feature to enable the system to automatically upgrade the CAStools of the cloud host. After you enable this feature for a cloud host, the system upgrades the CAStools for the cloud host at one o'clock a.m. the cloud host time by default. If you want to upgrade the CAStools for multiple cloud hosts at the same time, you must enable the time synchronization feature.
Clock Type	Select a clock type. To set the local system time, select the local clock. To set the UTC time, select the world clock.
I/O Priority	Select the priority for the cloud host to read and write disks of the host where the cloud host resides. When multiple cloud hosts are accessing the disks of the host to perform read and write operations, cloud hosts with a high I/O priority take precedence.
Startup Priority	Select a startup priority for the cloud host. When a host in an HA-enabled cluster fails, the system migrates the cloud hosts on the host based on their startup priorities. This parameter is available only when the host where the cloud host resides is in an HA-enabled cluster.
Blue Screen Policy	Select the action to take on the cloud host after the cloud host fails. To use the blue screen policy, you must enable HA and install CAStools for the cloud host.
No processing	Not take any action.
Restart	Restart the cloud host.
Migrate	Migrate the cloud host to another host in the cluster.
CAStools Type	Select a CAStools type.
Hardware Version	Select the QEMU version used by the cloud host. The larger the value, the later the version. After the management platform is upgraded, the hardware version of the cloud host is also upgraded. After the upgrade, the hardware of the cloud host might be incompatible with its OS, and a blue screen or boot failure might occur. To solve this issue, roll back the hardware version of the cloud host to the original version.
Integrity Check	Configure whether to enable integrity check. Integrity check verifies integrity of the disks of a cloud host when the cloud host starts. If integrity check fails, the cloud host cannot start. Disk integrity check might cost a long time.

Parameter	Description
CPUs	Set the number of CPUs for the cloud host, which cannot be more than the maximum number of CPUs on the host. If you change the number of CPUs on a cloud host that supports hot-add of CPUs, the operating system of the cloud host might operate slowly for 3 to 5 seconds. For a Linux cloud host, do not perform CPU hot-add during cloud host startup. Windows 7 supports a maximum of two CPUs. To improve processing performance, you can set multiple cores for each CPU.
CPU Cores	Specify the number of CPU cores.
Operating Mode	Select a CPU operating mode.
Compatible	Virtualizes physical CPUs of different models into vCPUs of the same model. This mode features good migration compatibility.
Host Matching	Virtualizes physical CPUs of different models into vCPUs of different models. This mode features bad compatibility but provides better performance for the operating systems of cloud hosts than the Compatible mode.
Passthrough	Enables the cloud host to access the physical CPUs directly. This mode features bad compatibility but provides better performance for the operating systems of cloud hosts than the Compatible and Host Matching modes. To migrate a cloud host that uses the passthrough CPU operating mode, the source and destination hosts must use CPUs of the same model.
Max CPUs	Set the maximum CPUs can be assigned to the cloud host, which is the number of CPU sockets multiplied by the number of CPU cores.
Architecture	Select a CPU architecture. This parameter is available only when you select Compatible as the CPU operating mode. The 32-bit architecture supports only 32-bit operating systems. If you select the 32-bit architecture for a cloud host using a 64-bit operating system, the cloud host cannot be started after being shut down.
Scheduling Priority	Select a priority for the processes on the cloud host to preempt physical CPU resources. You can edit the scheduling priority for an online cloud host.
Reserve	Enter the number of CPUs on the host to reserve for the cloud host.
Limit	Enter the maximum host CPU frequency that a single CPU core of the cloud host can use.
Overall CPU Limit	Select whether to enable overall CPU limit. For example, if you set maximum host CPU frequency that a single CPU core of a cloud host that has 4 CPU cores can use to 200 MHz and enable overall CPU limit for the cloud host, the maximum host CPU frequency is 800 MHz for both the cloud host and a single CPU core of the cloud host.
Online Scale Down	Select whether to enable online CPU scale-down. A cloud host supports online CPU scale-down only when its operating system supports online CPU scale-down.

Parameter	Description
Edit Quota	Edit the memory size to be assigned to the cloud host. This value cannot exceed the memory size of the host. If the OS of the cloud host supports hot-add memory (CAStools is required for Linux operating systems), the memory added to the cloud host takes effect without rebooting. If the OS of the cloud host does not support hot-add memory, you must shut down the cloud host before editing the memory size. Hot-add memory is not supported for a cloud host if the cloud host uses a Linux OS, has an initial memory less than 4 GB, and has an IDE disk attached.
Reserve	Enter the memory to be reserved for the cloud host to the total available memory of the host in percentage. The host allocates specific memory to a cloud host based on the actual memory usage of the cloud host. You can reserve memory for a cloud host in case the cloud host needs more memory after the host memory is exhausted.
Limit	Enter the maximum host memory size that the cloud host can use.
Resource Priority	Select the priority for the cloud host to request memory resources.
Memory Ballooning	Select whether to enable memory ballooning. With ballooning enabled, the system dynamically allocates host memory to cloud hosts without shutting down cloud hosts. After you perform memory hot-add for a cloud host, you cannot configure memory ballooning for the cloud host directly. To configure memory ballooning for the cloud host, you must shut down the cloud host, edit its memory, and starts the cloud host again.
HugePages	Configure whether the cloud host can use HugePages memory of the host.

Parameter	Description
Storage Format	Select a storage format. You cannot edit the storage format if the cloud host is running, has snapshots, or has multi-level image files.
Storage	Set the storage size of the cloud host. The storage size you specified in this field defines the size of the user data space. The cloud host disk image file also contains system space. The used space equals the cloud host disk image file size, which is the system space size plus the user data space size. Therefore, the used space size might be larger than the configured storage size. You cannot edit the disk size of a cloud host if the cloud host has snapshots or multi-level image files or the provisioning mode is eager zeroed or lazy zeroed. To avoid data transmission failure, make sure no data is being transmitted before you scale up the high-speed disk of a running cloud host.
Provisioning	Select a storage volume provisioning mode. This parameter cannot be edited if the cloud host is in running state, the cloud host has snapshots, or the disk of the cloud host has multi-level image files. This parameter is not available if the disk type is block device.
Disk Cluster Size	Set the smallest amount of disk space that can be used to store a file. If a file is larger than a disk cluster, it is stored in multiple disk clusters. If a file is smaller than a disk cluster, it is stored in a dedicated disk cluster. A shared file system is mainly used to store cloud host image files. As a best practice, set the value of this parameter as large as possible to enhance disk read performance and save disk space. This parameter cannot be edited if the cloud host is in running state, the cloud host has snapshots, or the disk of the cloud host has multi-level image files. This parameter is not available if the disk type is block device.
I/O Limit	Enter the I/O read and write rate limits in KBps.
IOPS Limit	Enter the IOPS read and write limits.
Cache Mode	Select a disk cache mode.
Directsync	The cloud host reads and writes the physical disk.
Writethrough	The cloud host writes data to the host cache, and then to the physical disk.
Writeback	The cloud host writes data to the cloud host cache, then to the host cache, and finally to the physical disk.
None	The cloud host writes data to the cloud host cache, and then to the physical disk.
Hot Swappable	Select whether to enable hot swapping for the disk. This parameter is available if the bus type is High-Speed.
Disk Dataplane	Select whether to enable disk dataplane. Enabling this feature improves the disk performance but consumes more host resources.

Parameter	Description
vSwitch	Select a vSwitch for the cloud host.
Port Profile	Select a port profile for the cloud host.
Virtual Firewall	Select a virtual firewall for the cloud host. The incoming and outgoing data packets of the cloud host will be filtered based on the firewall rules.
MAC	Configure the MAC address of the cloud host.
IPv4/IPv6 Info	Configure the network parameters for the cloud host. Select IP-MAC Binding to configure the IP address of the NIC. If the IP address specified for the cloud host's NIC is different from the bound IP address, the NIC cannot communicate correctly. Select Manually Specify to configure the network parameters through CAStools. Select DHCP to configure the network parameters through DHCP. Make sure the cloud host is installed with CAStools and CAStools does not conflict with other services. For example, before configuring network settings for a Linux cloud host, you must disable NetworkManager.
Device Model	Select a NIC type. This parameter cannot be edited if the current NIC type is SR-IOV passthrough.
Fast Forwarding	Enable fast forwarding to improve the network performance of the cloud host. This feature is available only for high-speed NICs.
Hot Swappable	Select whether to enable hot swapping for the NIC. This parameter is available for high-speed NICs.
MTU	Set the MTU for the cloud host NIC.
Driver Type	Select a driver type for the SR-IOV passthrough NIC.
VLAN ID	Specify a VLAN ID for the SR-IOV passthrough NIC.

Tab	Parameter		Description
Console		Enable VNC Proxy	Enable or disable VNC proxy for the cloud host. You can click the icon to configure the VNC proxy server parameters, including VNC proxy server address, login name, and password. If the VNC proxy server is a host managed by CVM, the login name and password do not take effect.
More		Device Model	Select a graphics card model. If the cloud host OS is Fedora19 or Fedora20, do not select Cirrus. If you select Cirrus, display errors might occur.