Hello everybody!
Watch this video to find out how to recover data of an XCP-ng (Xen Cloud Platform next
gen) virtual machine from a Mirrored RAID1.
XCP-ng is a Linux distribution with a pre-configured Xen hypervisor and a ready-to-use Xen API
project.
XCP-ng stands for Xen Cloud Platform — next gen.
The main goal of this project is to provide a simple way to deploy infrastructure based
on virtual machines using Xen as a hypervisor and a powerful XenAPI to offer ready-made
solutions.
XCP-ng is compatible with most servers and that is why it enjoys great popularity.
However, just like with any other hypervisor, there may be factors that cause loss of access
to the virtual machine - both as a result of a system error, or a server breakdown.
As a result, you won’t be able to restore access to the virtual machine data without
resorting to third-party software tools.
In today’s video, I’ll show you how to extract files of a virtual machine stored
in a RAID array, that can’t be accessed in a conventional way, and do it with a good
data recovery utility - Hetman RAID Recovery.
Installing XCP-ng As for the ready-made Xen distribution, the
easiest way to deploy XCP-ng is to use an ISO image, available on the project’s website
. The
installation of XCP isn’t much different from the installation of Xen hypervisor.
In our channel, we have a very detailed video about installing XEN Hypervisor.
I will give the link in the description.
The only difference is that I’m going to install the system onto a mirrored RAID.
During the installation, you need to specify the disks and use them to build an array.
How to create a virtual machine As to creating virtual machines, it is also
very similar to how we do it with XEN Hypervisor.
To manage virtual machines, we will use XCP Center.
The program has an interface similar to XEN Center.
You can learn more about creating a virtual machine by watching a video about XEN Hypervisor.
Since this process is absolutely identical, I’m not going to focus on that, but switch
to the recovery aspects instead.
On this hypervisor, I have configured two virtual machines, one with Windows 10 and
another with Linux Ubuntu.
I’ll show you how to extract data from each of them.
How to recover data from a virtual machine If nothing happens when booting a virtual
machine, if it displays an error that cannot be fixed, or if there is a hardware failure
or system error in the work of your server - whatever the reason, but you can’t boot
the virtual machine.
Use a specialized data recovery tool, Hetman RAID Recovery: it supports recovery from all
popular RAID types and from virtual disks of various hypervisors, including XCP.
By default, XCP-ng uses LVM storage for its virtual machines.
This storage method has quite a lot of advantages if compared with VHD files, but sometimes
you need to use the file-based storage mode like in VMware ESX, and it may also create
additional difficulties for the recovery process.
In my case, this system is based on a mirrored RAID, which makes recovery even more complicated.
To begin the recovery process, take the disks out of the server and connect them to the
motherboard of a Windows computer.
If your motherboard lacks SATA ports or power connectors to use all the disks you need,
you can add adapters or expansions cards to solve the issue, and you can see them on the
screen right now.
When you connect the physical disks, which used to make up the RAID where virtual machine
files are stored, Hetman RAID Recovery will immediately display virtual machine disks
and their size.
How to find virtual machine disks If you stored a lot of virtual machines on
your hypervisor and it’s difficult to distinguish between them, there are a few commands to
help you.
You can do it as long as the server is operable.
To see which virtual disks belong to a specific virtual machine, you should run some commands
on the server to find the UUID (Universal Unique Identifier) of the virtual machine,
the UUID of its disk, and the UUID SR (Universal Unique Identifier of the Storage Repository).
To do that, connect to the server by SSH and type the first command:
xe vm-list As a result, you’ve found the virtual machine
UUID; Here is the identifier of the virtual machine
with Windows 10 and Linux.
Now you can use this identifier to view the connected disks, with the help of this command:
xe vm-disk-list uuid= aae7d446-4072-8966-b828-396b63082644 - in the end, the virtual machine UUID is
given.
As a result, you get the virtual disk UUID, which, in its turn, can be used to find the
storage repository UUID.
xe sr-list name-label=Local\ storage Now that we have the repository identifier,
it’s easy to understand to which virtual machine specific disks belong, and you’ll
be able to identify those disks in the data recovery utility.
8620cbbb-fc1a-2520-e97c-9a66486441fd.VHD Scanning a Windows virtual machine disk
All right, now we have taken the disks out of the server and connected them to a Windows
computer.
Download, install and start Hetman RAID Recovery.
The program has built the RAID system where virtual machine files are stored; below, you
can see the information it managed to identify.
A little lower, under the RAID, all virtual machine disks are displayed; if it’s difficult
to understand which of them you need, find it by the identifier.
In my case, there are only two virtual machines.
For starters, let’s scan the Windows virtual machine disk.
Right-click on the disk and select Open.
Select the scan type; start with “Fast scan.”
If the “Fast scan” can’t find the required files, then go for “Full analysis.”
To do it, return to the main menu, right-click on the disk and choose “Analyze again.”
You also need to select a file system: choose NTFS, as this is a virtual machine with Windows
10, and start the scan.
Then navigate to the folder where
the files were stored, select the files you want to restore, click “Recovery,” specify
the disk and folder where you’d like to save the files, and click “Recovery” again.
When the entire process is over, you will find the recovered files in the folder you
have chosen.
You can see that the program has no difficulty in finding the files that used to be stored
on the virtual disk.
To make the search easier, all our programs feature the option to search by file names.
Also, you’ll be able to preview the file contents.
Scanning a Linux virtual machine disk Now let’s see how good is this program at
recovering files from a Linux virtual machine.
Open the disk, and choose Fast scan to begin with.
As you can see, it has found the files - all the data which was stored on the virtual machine
disk.
The program even managed to find deleted files, and all you have to do is to restore them.
Hetman RAID Recovery supports all popular file systems, RAID types, and the majority
of hypervisors.
If the RAID system in question is damaged, the program will rebuild it automatically,
and let you retrieve the critical data you’re looking for.
How to recover data manually, with the RAID Constructor
When a disk is damaged or service information is erased, the program may have difficulty
in rebuilding the RAID automatically; however, you can do it manually with the RAID Constructor
if you know the properties of this damaged array.
Open the Constructor, select Manual mode, and fill in all the information you know about
this disk array: the RAID type, block order and size.
Add the disks it used to include, use the arrows to specify their order, and replace
the missing disks with empty drives by clicking the “plus” button.
Also, you can specify the offset that helps to locate the beginning of the disk.
Sometimes, the program may have difficulty in identifying it automatically, so you’ll
have to enter the offset value manually.
Usually, if you give correct properties, the newly built RAID system has at least one partition.
Expand it to check for the folders that you need.
If the folders you are looking for are displayed, then you have built this RAID properly.
When you specify all the properties you know, click “Add,” and the array will appear
in the Drive Manager.
To have the array recovered, the last step is to scan it, find the files you want to
restore, select them, and recover to the folder you choose.
That is all for now!
Hopefully, this video was useful.
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Leave comments to ask questions.
Thank you for watching.
Good luck.