Prepare source VMs/instances for recovery to an Azure cleanroom site

Prepare your source VMs/instances for recovery to Azure VMs in an Azure cleanroom site.

Hyper-V driver requirements

Recovering to an Azure cleanroom site requires that the source VMs/instances have certain Hyper-V drivers and have Dynamic Host Configuration Protocol (DHCP) enabled.

Commvault automatically handles these requirements for VMware source VMs as follows:

Red Hat Enterprise Linux (RHEL): When the recovery is performed with auto-scaled access nodes that match the Azure subscription, region, and Availability Zone (AZ) of the recovered VMs
Windows Server: All cases

Linux

To facilitate post-recovery validation, install the Azure Linux VM Agent.

This step is not required to perform cleanroom recovery operations. It simply facilitates post-recovery validation, such as running validation scripts.
Enable Secure Shell (SSH).
Enable Remote Desktop Protocol (RDP).
For VMware VMs with any flavor of Linux other than Red Hat Enterprise Linux (RHEL), install the required Hyper-V drivers. For Amazon EC2 instances, installing the drivers is not required, but it is a best practice because the drivers are not pre-installed in all cases.
1. Run a backup of the VMs/instances.
2. Identify the current kernel version:
```
uname -r
```
3. Check whether required drivers are already a part of the initrd image for the guest VM:
```
lsinitrd | grep -i hv
```
4. Go to the boot folder:
```
cd /boot
```
5. Take a backup of the initrd image:
```
cp initrd-$(uname -r) initrd-$(uname -r).backup
```
6. Insert the drivers and recut the initrd image:
```
mkinitrd -v -m "hv_vmbus hv_netvsc hv_storvsc" -f /boot/initrd-$(uname -r) $(uname -r)
```
7. Check whether Hyper-V kernel modules got installed successfully:
```
lsinitrd | grep -i hv
```
8. Verify that the size has changed:
```
ls -l
```
For the following source VMs/instances, enable DHCP:
- VMware VMs with any flavor of Linux other than Red Hat Enterprise Linux (RHEL)
- Hyper-V VMs
The following steps use dhclient.
1. Open a terminal with a user account that has root privileges.
2. Identify your network interface:
```
ip link show
```
  Look for your active interface name (such as eth0, ens33, or wlan0).
3. Bring the interface down:
```
sudo ip link set eth0 down
```
4. Bring the interface up:
```
sudo ip link set eth0 up
```
5. Request an IP address from DHCP:
```
sudo dhclient eth0
```
  This command contacts the DHCP server and assigns an IP address to the interface.
6. Verify the IP address:
```
ip addr show eth0
```

Windows Server

To facilitate post-recovery validation, install the Azure Windows VM Agent.

This step is not required to recover VMs/instances to a cleanroom site. It simply facilitates post-recovery validation, such as running validation scripts.
Enable a SAN policy so that disks can be brought online after they're recovered:
1. Log on to the VM/instance.
2. Open a command line or a PowerShell session.
3. Open the disk partition tool:
```
C:> diskpart
```
4. Verify that the SAN policy is set to Offline Shared:
```
DISKPART> san
san policy : Offline Shared
```
5. Change the policy to OnlineAll:
```
DISKPART> san policy=OnlineAll
```
6. Restart the VM/instance.

Linux and Windows Server

VMs/instances that host Active Directory

For VMs/instances that host Active Directory, if you want the Commvault to automatically perform health checks of your recovered AD environment, install the Commvault Active Directory package.

The health checks validate the following critical AD services for user authentication and domain functionality:

Netlogon service: Manages authentication health check in AD
NTDS service: Stores and replicates the AD database
KDC service: Issues Kerberos tickets for user authentication

From the Command Center navigation pane, go to Manage > Servers.
In the row for the VM/instance, click the action button , select Maintenance, and then select Add software.
From the Select packages list, select Active Directory, and then click OK.
Click Install.

Recovering individual files

If you want the ability to recover individual files, install the Commvault File System package on the VMs/instances.

From the Command Center navigation pane, go to Manage > Servers.
In the row for the VM/instance, click the action button , select Maintenance, and then select Add software.
From the Select packages list, select File System, and then click OK.
Click Install.

Nutanix AHV instances with a firewall

For Nutanix AHV instances that have a firewall, disable the firewall before running the backup that you will use for the recovery.

Hyper-V differencing disks

For Hyper-V VMs, if you have differencing disks (AVHD or AVHDX files), merge the disks with the original disk.

For instructions, see How to merge checkpoints that have multiple differencing disks in the Microsoft documentation.

Epic EHR databases

If a file system that hosts an Epic EHR (InterSystems IRIS Caché) database is directly on a disk, identify the correct disk and update the fstab file with an appropriate restored disk for the file system.
For recovering an Epic EHR database to a Linux VM in an Azure cleanroom site, see Prepare a Red Hat-based virtual machine for Azure.