This section explains advisory notes for RHEL-KVM.
VM Type View
In the ROR console, the VM type of RHEL-KVM VM hosts and VM guests is displayed as "RHEL-KVM".
Snapshot
The operations that can be performed differ depending on the disk configuration and power status of the L-Server.
Conditions for collecting, restoring, and deleting of snapshots are as follows:
The L-Server is powered off
The operations that can be performed differ depending on the type of the disk resources connected to the L-Server, as shown below.
Operation | Type of Disk Resources Connected to the L-Server | ||
|---|---|---|---|
Raw Disks Only | Virtual Disks Only | Both Raw Disks and Virtual Disks | |
Collection | No | Yes | No |
Restoration | No | Yes | Yes |
Deletion | No | Yes | Yes |
Yes: Possible.
No: Not possible.
Note
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Restoring the collected snapshots resets the following parameters for the L-Server back to the state at the time when collection was performed.
Number of CPUs
CPU Performance
Memory Size
Maximum Memory Size
Disk Configuration
Networks
OS Settings
Guest OS Automatic Configuration
When using RHEL-KVM, guest OS auto-configuration can be used for Linux, Windows, and Linux (SELinux).
Note
When the OS type is Windows, OS auto-configuration can be used for the OS versions described below.
"8.6.7 Collecting Cloning Images"
When using a Windows cloning image
OS versions supporting the OS auto-configuration functions
Detaching Disks and Deleting L-Servers
The data in the disk resources for virtual L-Servers cannot be deleted when detaching disks or deleting L-Servers, except when deleting the disk details for virtual L-Servers is enabled using the definition files.
Therefore, it is recommended to delete the data from the disk.
For details on how to delete data on disks, refer to "14.5 Storage Resources" in the "User's Guide for Infrastructure Administrators (Resource Management) CE".
For details on how to specify definition files, refer to "8.6.1 Creating Definition Files".
Configuration for L-Server Live Migration
In RHEL-KVM environments, use SSH to perform live migration on virtual L-Servers.
It is necessary to configure each involved host to enable live migration of an L-Server from the manager.
For details, refer to "E.5.2 Preparations for Servers" in the "Design Guide CE".
Note
When performing live migration using the virsh migrate command for KVM, specify both the --undefinesource and --persistent options.
If the command is executed without specifying these two options, the same VM guests may exist on both the destination and source VM hosts. In this state, the VM guests cannot be turned on using Resource Orchestrator. This occurs to prevent double VM guest startup operations in the state that multiple instances of the same VM guest exist on different VM hosts.
When turning on VM guests, the state where there are multiple instances of the same VM guest must be avoided by using the virsh command.
For details, refer to the following section in the "Red Hat Enterprise Linux 6 Virtualization Administration Guide".
Chapter 14. Managing guest virtual machines with virsh
URL: http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/Virtualization_Administration_Guide/index.html |
The manuals for Red Hat Enterprise Linux can be referred to from the following URL.
URL: https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/index.html |
Max. Number of Possible L-Servers View
The available space on resources and the space displayed for [the number of L-Servers that can be created] are calculated as follows:
Available Amount of CPUs and [Number of L-Servers that can be Created]
Total resource space - (Total of resources reserved for VM hosts + Total of resources used for L-Server) |
Directory for collecting performance information
When resources are registered, the directories and files that are necessary for performance monitoring are created on the server where the resources are registered.
The directories and files are created in the following location. (Files with the same name in the same location are overwritten.)
/{Home directory of the user ID specified when registering the resources}/dsa_temp_*Do not delete the above directory until the resources themselves are deleted.
Performance information will not be collected if this directory is deleted. Restart the Manager if the directory is deleted accidentally.
The above directory is not automatically deleted when the resources are deleted. Delete it manually.
Live Migration to Copy Disks between Storage that are not Shared
Do not perform live migration to copy disks between storage that are not shared, from within VM software.
Such operation is not supported by Resource Orchestrator.
Migration
When specifying cold migration for migration while powered on, migration may fail.
Perform migration after powering off. After that, wait a couple of minutes and then power on again.
Corrective Action for Failure of a VM host Registered as Storage Management Software
When a VM host registered as storage management software fails, creation and deletion of virtual L-Servers and addition and deletion of disks cannot be performed using the virtual storage (libvirt storage pools) managed by the storage management software.
In order to make these operations possible, it is necessary to change storage management software.
Change the IP address of the storage management software to the IP address of a VM host which has the same sharing configuration for libvirt storage pools as the failed VM host.
To change the IP address of the storage management software, execute the modify subcommand of the rcxadm storagemgr command.
For details on the rcxadm storagemgr command, refer to "5.17 rcxadm storagemgr" in the "Reference Guide (Command/XML) CE".
Specification of Enable/Disable of the memory_hotplug Function
The value specified for enable/disable of the memory_hotplug function is configured for each individual virtual L-Server while creating a virtual L-Server.
However, the configured value cannot be modified after creating a virtual L-Server.
For details on memory_hotplug, refer to "8.1.2 VM Specific Information Definition File".