Update VM Configuration

You can add storage and additional network interfaces to your virtual machines (VMs).

Add Disk Storage

KubeVirt allows hot plugging additional storage into an active VM. Both block and file system volume types are supported. Disks are "hot plugged" into your VMs, meaning that you do not need to power off the VM in order to add disks.

Prerequisites

• A deployed VM in an active cluster that has the Virtual Machine Orchestrator (VMO) pack.

Add a Disk

1. Log in to Palette.

2. From the left Main Menu, click Clusters and click on your cluster.

3. Navigate to Virtual Machines > Disks tabs and click the Add disk button.

4. Review the parameters and update as needed. You can specify the disk size, disk type (Disk, CD-ROM, or LUN), and network interface.

   The interface type determines out-of-the-box operating system (OS) support and disk performance. Choose from the following.

   Interface type	Description
   virtio	Optimized for best performance, but the operating system may require additional Virtio drivers.
   sata	Most operating systems support Serial ATA (SATA). However it offers lower performance.
   scsi	A paravirtualized Internet Small Computer System Interface (iSCSI) HDD driver that offers similar functionality to the virtio-block device but with some additional enhancements. In particular, this driver supports adding hundreds of devices and names devices using the standard SCSI device naming scheme.

5. Next, specify the access mode for your disk.

   Access mode	Description
   Read-Write-Once (RWO)	Ensures that only one client can write to the volume at any given time.
   Read-Write-Many (RWX)	Allows multiple clients to read from and write to the volume simultaneously.
   Read-Only-Many (ROX)	Permits multiple clients to read data only.

6. Specify the volume mode for your disk.

   Volume mode	Description
   Filesystem	The volume is formatted with a filesystem. The OS manages the volume using a directory structure, where files are stored in folders.
   Block	The volume is presented as a raw block device. The OS manages the volume at the block level, without any filesystem structure.

7. If you'd like to allocate storage to the VM right away, check Enable preallocation. Otherwise, the storage is allocated to your VM as data is written to the storage.

8. Click Add when you are done.

Validate

The Disks tab lists the newly added disk as PersistingHotplug.

Add Network Interfaces

You can add additional network interfaces to a VM. By default, VMs use the native networking already configured in the pod. Typically, this means using the Bridge option, and your VM has the same IP address as the pod. This approach makes interoperability possible. The VM can integrate with different cases like sidecar containers and pod masquerading.

When using pod masquerading, you choose a CIDR for which VMs are not assigned a private IP, and instead use Network Address Translation (NAT) behind the pod IP.

Multus is a secondary network that uses Multus-CNI. Multus allows you to attach multiple network interfaces to pods in Kubernetes. If you use Multus as your network, ensure that Multus is installed across your cluster and that you have created a default NetworkAttachmentDefinition CRD. For more information, refer to the Multus CNI guide.

Prerequisites

• A deployed VM in an active cluster that has the Virtual Machine Orchestrator (VMO) pack.

• The VM must be in the Stopped state.

Add an Interface

1. Log in to Palette.

2. From the left Main Menu, click Clusters and click on your cluster.

3. Navigate to Virtual Machines > Network Interfaces and click the Add network interface button.

4. Review the parameters and update as needed. Interface types are: Masquerade, Bridge, and SR-IOV.

5. Click Add when you are done.

info

Multus allows hot plugging network interfaces only when interfaces use the virtio model connected through bridge binding.

Validate

The Network Interfaces tab lists the newly added interface.

Resources

• Multus CNI