Preparing UNIX VMs with Oracle Linux 8, RHEL 8, and Later for Conversion to VMware Cloud Director

Before restoring a UNIX-based virtual machine (VM) to VMware Cloud Director, specific preparatory steps are required to ensure a successful conversion and power-on. All necessary steps are described below, including an important additional step for Oracle Linux 8, RHEL 8, and later versions to ensure the vmw_pvscsi driver remains persistently loaded.

Applies To

Oracle Linux 8 and later
RHEL 8 and later

Overview

During the VM conversion process to VMware Cloud Director, certain SCSI drivers, especially vmw_pvscsi, must be available in the initial RAM disk (initrd) or built into the kernel. Without these, the converted VMs will fail to boot.

Procedure

Check if vmw_pvscsi is built into the kernel. Check the kernel configuration by running the following command:
```
grep -i pvscsi /boot/config-$(uname -r)
```
Interpret the output as follows:
- If it contains CONFIG_SCSI_VMW_PVSCSI=y, then the driver is built into the kernel. No further action is needed.
- If it shows CONFIG_SCSI_VMW_PVSCSI=m, the driver is a module and must be included in the initrd.
Check if vmw_pvscsi is in the initrd. Run the following command:
```
lsinitrd | grep -i vmw_pvscsi
```
If no output is returned, the module is not included in the initrd and must be added.
Ensure the vmw_pvscsi driver is persistently loaded. Run the following command to persist the module across reboots:
```
echo "vmw_pvscsi" | sudo tee /etc/modules-load.d/vmw_pvscsi.conf
```
This ensures that the vmw_pvscsi module is loaded every time the system boots.
Rebuild the initrd image as follows:
1. Make a backup of your existing initrd by running the following command:
```
 cp /boot/initramfs-$(uname -r).img /boot/initramfs-$(uname -r)-backup.img
```
2. Rebuild the initrd with the required driver by running the following command:
```
dracut --force --add-drivers "vmw_pvscsi" -v
```
  Alternatively, regenerate all initrd images (not usually required unless you need full regeneration) by running the following command:
```
dracut --force --regenerate-all
```
  Or for the current kernel only:
```
dracut -f /boot/initramfs-$(uname -r).img $(uname -r)
```
Verify vmw_pvscsi is in the rebuilt initrd by running the following command:
```
lsinitrd | grep -i vmw_pvscsi
```
The output will confirm that the driver is included.
Reboot the VM running the following command:
```
reboot
```
After the VM reboots, verify that the vmw_pvscsi module is loaded by running the following command:
```
lsmod | grep vmw_pvscsi
```
The output will indicate that the module is loaded.

Other Important Considerations

Ensure DHCP is configured for the source VM. Static IPs are not retained during conversion.
For Linux VMs, the failure to load required drivers such as vmw_pvscsi will prevent the VM from booting in VMware Cloud Director.
For Azure VMs, do the following:
- Ensure that Windows VMs have the pagefile enabled on the C: drive.
- Ensure that Linux VMs have fstab entries using UUIDs, not disk names.

Post-Conversion Actions

You may need to manually update disk assignments, especially for UEFI-booted systems or when multiple disk controller types are used.
VMware Tools is not automatically installed. Use the vSphere client to install them after conversion.
Disks for Windows VMs may be offline post-conversion. Bring them online manually.