Red Hat KVM plug-in guidelines

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Kernel-based Virtual Machine (KVM) is a virtualization solution for the Linux kernel. Snap Creator uses the KVM plug-in to back up and restore the guest virtual machines.

Note For the latest information about support or for compatibility matrices, see the Interoperability Matrix.

The KVM plug-in supports guest operating systems such as Linux, Windows, and Solaris.

The plug-in internally uses virsh commands.

You must consider the following when you use the KVM plug-in:

  • Active IQ Unified Manager server as a proxy is not supported.

  • Mount, unmount, and backup operations using Open Systems SnapVault, and archive log management, are not supported.

  • In a storage area network (SAN) environment, the Linux Host Utilities (LHU) kit is required to collect information about LUNs and volumes from the storage controller.

    The LHU kit should be installed on a KVM hypervisor, which is the same location as the Snap Creator Agent.

    Note If the LHU kit is not installed and the configuration is a mix of network attached storage and storage area network environments, then the backup and restore operations work only on a Network File System (NFS).
  • The KVM plug-in supports only the Linux version of the Snap Creator 4.0 and 4.1 Agent.

  • Volume restore is not supported; only application-defined restore operations are supported.

  • The deleted virtual machines (VMs) cannot be restored.

  • The storage controller IPs and host should be either in /etc/hosts on the KVM host or in a Domain Name System (DNS).

  • Only one KVM host per configuration is supported.

  • If a virtual machine is created by using an ISO repository, then to perform any action, you should disconnect this repository from the virtual machine through the Virt Manager console in CD-ROM options.

  • The SC_AGENT_TIMEOUT value should be more than the default value: 600 or higher.

  • The volumes are automatically discovered using automatic detection.

    You cannot see the discovered destination volumes if the destination is not in a SnapMirror relationship. You should use dpstatus to check the status of the SnapMirror relationship. If a SnapMirror relationship does not exist, you must first create the SnapMirror relationship.

  • If the value of APP_DEFINED_RESTORE is Y, then the SnapVault restore operation using the GUI is not supported.

  • When creating a SnapMirror and SnapVault configuration by using the GUI, the volume details must be entered manually because the SnapMirror and SnapVault relationship is not detected automatically.

  • Data disks mapped to the VMs are not backed up.

  • VM suspend and resume operations are performed serially.

    For multiple VMs, the duration of VM in suspend state during backup operation depends on number of VMs.

Supported KVM configurations

  • SAN: Supports guest virtual machines installed on a raw multipath device (LUN with multiple paths).

  • NAS: Supports guest virtual machines installed on NFS volumes.

Note Configurations with multiple virtual machines installed on a single multipath device are not supported.

Guest virtual machines installed on LVM or on an image file in the SAN environment are not supported.

The following table describes the KVM plug-in parameters:

Parameter Setting Description

KVM_RESTORE_VM_LIST

Example: VM1,VM2

Specifies the list of VMs to be restored. This parameter is required only during restore.

KVM_VM_MAPPING

Example: VM1:s_c1:/vol/vol1/lun1;VM2:s_c2:/vol/vol2/lun2;

(Required) Specifies the mapping between the VM and its associated storage controller, LUN, or file path. This parameter is updated dynamically during the discovery process.

KVM_VM_CONFIG_DIR

Default: /etc/libvirt/qemu

(Optional) Specifies the path to the directory where all the XML configuration files of the VM are stored.

KVM_CMD_RETRY_COUNT

Default: 3

(Optional) Specifies the number of times you rerun the command when running it fails in the KVM plug-in.

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