DRaaS failover prerequisite checks



Overview
Are the VMs in your environment DR ready? Find out this and more as Phoenix automates this process for you with the Prerequisites checks capability. When the VMs are being backed up, the prerequisites checks kick into action and provide the status; if the VMs have successfully cleared the checks and are DR ready or not.
With these checks in place, you can prepare a robust DR strategy and avoid any surprises during failover. It further helps you reduce failed requests to the cloud, and your cloud spending too!
The status of the failover prerequisite checks is available through the Virtual Machines page.
The following diagram illustrates the capability.
Watch the video
- ► Expand for a feature overview video that provides more insights about the failover prerequisite check capability.
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Assign credentials
To use the DRaaS prerequisites checks capability, ensure that the credentials you assign to virtual machines meet the following requirements:
Windows virtual machines
- The account must have administrator level permissions.
- For a Windows domain user, the credentials must be entered in the following format <UserName>@<DomainName> and <password>.
- UAC must be disabled on the virtual machine. See disabling UAC on Windows server for more information.
Linux virtual machines
- The account must have sudo privileges
Assigning credentials to virtual machines
To assign credentials to a virtual machine, perform the following tasks:
- In the organization that contains your virtual machine, navigate to Protect > VMware.
- In the navigation pane on the left, under vcenter/ESXi host, select the vcenter server or ESXi host that hosts the virtual machine.
- On the All Virtual Machines page, select the virtual machine that needs to be configured for DR, and click Manage Credentials.
- Click Add Credential to create a new credential, or select an existing credential. Click Assign.
Note: Ensure that the backup proxy is version 4.8.11 or higher. For more information on upgrading the backup proxy, see Upgrade backup proxy.
Failover prerequisites check statuses
The following table describes the failover prerequisites check statuses
Status | Description |
---|---|
Success | Failover prerequisites check passed. |
Not initiated | Prerequisites check could not be initiated because either:
|
Invalid credentials |
Prerequisites check could not be performed because either:
|
Missing credentials |
Failover prerequisites checks could not be performed because credentials are not assigned to the VM. See, Configure virtual machines for backup. |
Error | Failover prerequisites check failed. See, DRaaS failover prerequisite checks |
Warning | Prerequisites check passed with warnings. It is recommended to fix the warnings even though the failover won’t fail if not resolved immediately. |
Resolving DR failover prerequisite checks
After you resolve the checks, trigger a new back job and only after all the checks are successful, the VM is DR ready.
Linux failover prerequisite checks
Check | Description |
---|---|
Source Metadata Collection |
What is verified Verifies that all required metadata was collected from the source. Potential errors
Recommendation
|
Free Space |
What is verified Verifies there is enough free storage space. Potential errors The source does not have enough free space on {MPOINT} ({DEVICE}). At least {SIZE} Mb needed space is required․ Recommendation Provision additional free disk space as described in the message. |
Bootloader |
What is verified Verifies the source boot loader is supported. Potential errors Source has an unsupported version of GRUB. Please install grub-legacy or grub2 on the source and try again․ Recommendation Ensure that grub-legacy or grub2 is installed on the source virtual machine. Else, install the grub package on the source virtual machine. Review the GRUB installation documentation for your operating system. For example for CentOS refer to: https://wiki.centos.org/HowTos/GrubInstallation. |
OS Support |
What is verified Verifies the source operating system is supported. Potential errors
Recommendation Review the system requirements. |
Cloud-init Configuration |
What is verified Checks cloud-init configuration for potential problems. Potential errors
Recommendation
|
Supported FS |
What is verified Verifies source filesystems are supported. Potential errors {DEVICE} has {FS_TYPE} filesystem, which is not supported. Recommendation One of the devices has an unsupported FS. Failover can continue if it is excluded. For failover, this means the file system might be missing from the target. See, Configure virtual machines for backup. Ensure that the disk to be excluded does not have following mountpoints : "/", "/usr", "/var" ,"/boot" |
Selected Disks |
What is verified Verifies failover can proceed with only the selected disks. Potential errors
Recommendation
|
LVM PVs |
What is verified Verifies LVM physical volumes are on supported storage devices. Potential errors Device {DEVICE} which is a PV for LVM Volume Group {VOLUME_GROUP} (mount: {MOUNT}) was not recognized as a supported device. Recommendation The block device which holds the volume was not recognized as a supported device. Failover can't continue if the volume is critical.
|
XEN/AWS Platform Details |
What is verified Checks if the type of XEN hypervisor can be detected (does nothing for non-XEN). Potential errors Could not determine if this xen-based source is an AWS EC2 instance, as instance metadata could not be retrieved. Recommendation Couldn't reach the AWS metadata service to determine this is an AWS instance. The instance ID will be missing. Verify if network settings are correct on ec2-instance. Verify if "http://169.254.169.254/latest/meta-data/" is reachable from the instance. To verify, launch a temporary EC2 instance with the same configuration as the failover instance. If the metadata URL is not reachable from the temporary EC2 instance as well, refer to the AWS documentation for more information. |
DHCP Configuration |
What is verified Checks the source DHCP config for unsupported options. Potential errors DHCP configuration contains 'supersede'. Target might have a broken network. Recommendation The EC2 instance has custom DHCP client configurations. Druva doesn't reset the configurations. This could potentially cause issues. Verify the /etc/dhcp/dhclient.conf of the EC2 instance. |
Required Mounts |
What is verified Verifies the required mount points were recognized. Potential errors /mountpoint is mandatory. Recommendation Ensure that the VMDK containing "/" mountpoint is not excluded from backup. |
Windows failover prerequisite checks
Check | Description |
---|---|
Hyper-V |
What is verified Verifies the source is not a Hyper-V host. Potential errors The source is running hyper-v. Migration of hyper-v servers is not supported by Druva. Hyper-V server will not be able to run in the target cloud and the source will fail to start in the target cloud environment. Recommendation Hyper-V is not supported. |
OS Support |
What is verified Verifies the source operating system is supported. Potential errors This OS is not supported for conversion. Please review our documentation for supported OS for conversion. Recommendation Review the system requirements. |
PV Drivers |
What is verified Verifies the source doesn't have 'AWS PV Network Device' NICs. Potential errors TCP offloading must be disabled on source with driver type {DRIVER}. Recommendation If phase 2 system has no network, disable TCP offloading on the source. To disable TCP offloading
|
Pending Updates |
What is verified Verifies there are no Windows Updates scheduled to happen on reboot. Potential errors Source has pending updates detected. Recommendation Windows updates are running on the source machine. A reboot is scheduled. The VM might reboot unexpectedly when booted into the final target OS. It might cause failover to fail. Wait for the updates the complete. |
Network Drivers |
What is verified Verifies there are no incompatible NIC drivers installed. Potential errors Citrix PV Ethernet Adapter is not supported during AWS conversion. Recommendation The Citrix driver installed on the source might cause problems in phase 2. Uninstall the driver. |
.Net |
What is verified Checks whether the required version of .Net Framework is installed. Potential errors Microsoft .NET Framework v{VERSION} will be installed. Recommendation This is an information message. It can be ignored. |
Supported FS |
What is verified Verifies source file systems are supported. Potential errors The source has unsupported file systems '{FS_TYPE}' (volume {VOLUME_ID}, mount point {MOUNT_POINT}). Volumes with a non-supported file system can not be transferred. Recommendation One of the devices has an unsupported file system . Failover can continue if it is excluded. See, Configure virtual machines for backup. Ensure that the disk to be excluded does not have following mountpoints : "C:" |
Sysprep State |
What is verified Verifies previous Sysprep run wasn't incomplete. Potential errors Druva has discovered that a previous Sysprep attempt did not complete properly on the source VM. In the registry navigate to ''HKEY_LOCAL_MACHINE\\SYSTEM\\CurrentControlSet\\Control\\Session Manager\\'' and locate the key ''BootExecute''. Remove the line containing ''sysprepDecryptor.exe'' and reboot the source VM before migrating. Recommendation In the registry navigate to HKEY_LOCAL_MACHINE\\SYSTEM\\CurrentControlSet\\Control\\Session Manager\\ and locate the key BootExecute. Remove the line containing sysprepDecryptor.exe and reboot the source VM before migrating. |
Is Domain Controller |
What is verified The source VM is a Domain Controller. Potential errors It appears that the source VM is a Domain Controller. Recommendation Domain controllers sometimes are slow to boot (might cause time outs) and are generally more prone to errors during failover. Use larger instance-type like m4.xlarge family for running failover. |
Free Space |
What is verified Verifies there is enough free storage space. Potential errors The source VM doesn't have sufficient space on C volume. Druva requires {TOTAL_SPACE_REQUIREMENT} MB free space on C volume. Recommendation Provision additional free disk space as described in the message. |
Antivirus Software |
What is verified Checks whether the source has AV/protection software installed. Potential errors {AV_NAME} antivirus software detected (service name: {SERVICE_NAME}). If failover fails, try whitelisting Druva software components. Recommendation Antivirus software blocks cli.exe or some other executable during failover. Try whitelisting the executables. |
Selected Disks |
What is verified Verifies failover can proceed with only the selected disks. Potential errors
Recommendation Consider removing the disk from the backup and selected_disks. See, Configure virtual machines for backup. Ensure that the disk to be excluded does not have following mountpoints : "C:" |