Expert Mode: Setting up your Snapshot RAID

This tutorial will guide you through the creation of your first Snapshot RAID configuration. We will keep here the most basic configuration and default settings.

Advanced Tutorials provides more information details on some of the advanced settings.


Creating your Snapshot RAID configuration

Launch the FlexRAID user interface, and click on Add New Configuration button the top left side of FlexRAID Desktop


It will open the Add New Configuration window, allowing to create a FlexRAID configuration.


In this window, type the name of the configuration, and leave the Type in “Snapshot”.


Enter the number of DRUs and PPUs that you want to use in the Snapshot RAID:
DRUs (Data Risk Unit): your data containers (drives or folders). Each DRU can be of various size, and can contain one or several drive or folder
PPUs (Parity Protection Unit): Space that will be used by FlexRAID store the parity data

The number of PPUs used will determine your fault tolerance: how many DRU or PPU, also called UoR for Unit of Risk, can die without you loosing data.


Note: A good practice is to create more DRUs than you actually need, leaving at first some empty, to cope with later extension (even though this is possible later). But you have to select the exact number of PPU that you will actually use.
You can see here more explanation about DRUs and PPUs.

In this example, we’ll use 3 DRUs and 1 PPU – but add 2 more DRUs for later extensions.


You will now select the RAID engine you want to use. FlexRAID supports several types of RAID engines, you need to pick one that is in relation to the number of PPUs you have selected.

Supported engines are (see here for more details):
T1: similar to RAID4, supports unlimited number of DRUs, and 1 PPU. As such it will tolerate 1 failure. T1+ refers to an optimized T1 engine
T2: similar to a RAID4/6 combo, supports unlimited number of DRUs, and up to 2 PPU. It will support up to 2 failure. T2+ refers to an optimized T2 engine, but supports a max of 31 DRUs
Tx: by far the most flexible engine, is an optimized RAID∞™ engine. It supports an infinite number of DRUs and PPUs.

In this example, we will use the Tx engine, even though we’re using only 1 PPU.


You can now hit the Create button.

This will add a shortcut to your newly created RAID configuration in FlexRAID user interface desktop:


Click on this new icon – It opens your Snapshot RAID’s configuration window.

This windows contains several sections:
– the Data Configuration, where you will configure each DRU and PPU
– the Run-Time Properties, where you will configure additional options on your RAID configuration
– the Command Execution Center, where you will perform actions on your Snapshot RAID.


Set your Data Configuration.
On the left side, you will see an explorer-like view allowing to pick the drives (or folders) that you wish to add to your RAID Configuration. On the right side, you will see your DRUs and PPUs.

To configure a DRU or PPU:
– Click on the DRU or PPU – it will span open
– Drag the source drive or folder into the DRU or PPU, until it displays . If it displays , drag it closer to the top.

In this example, I:\ drive has been successfully added to DRU1.


Repeat this process for each DRU, and then for your PPU.
In the example, we’ve added:
– I:\, J:\ and K:\ to DRU1, DRU2 and DRU3
– Q:\ to PPU1


[optional] Set the Run-Time Properties: Click now on the Run-Time Properties section – it will close the Data Configruation and open the new section.

You can still increase the Processes to number of core + 1, that will take full usage of multi-core architecture and improve performances. You can leave these options to their default value. Otherwise, refer to the Extended Tutorials section for more explanation of what they mean.


Once done, hit the Save button.


You’re done – your Snapshot RAID is configured, you can now create the parity data!



Create your RAID parity data!

You are now done with the configuration, you can now launch the RAID Creation process. This process will compute the parity data out of all your DRUs, and write that data to the PPU(s) you have configured. Once this is done, you will be protected! Note that this is a lengthy process, that depending on the amount of data can last from several hours or days. As an example, if you have 20TB combined data in your DRUs, it can take around 12 to 14 hours.

Click on the Command Execution Center section. This will span open.

The upper part is where the FlexRAID program will display feedback about tasks being processed, and the lower part allows you to launch commands.
Right now, since your RAID is not fully created, only the Create button is available.


When you’re ready, hit the Create button.

This will launch the creation process. In the middle of the window, you will have a log of the completed task, as well as the progress of the on-going task. You can now wait until this process completes.


Process is complete: You’re now protected!
Once the Parity Creation Process completes, the window will be updated with the status.

If successful, you can now consider that your data is protected with the level of protection you’ve selected.



Going further: your next steps with FlexRAID

You can also see that the bottom of the window has been updated with new commands.

Those commands will allow you to perform maintenance tasks on your RAID array:
Update allows you to keep your RAID in sync
Quick Validate allows to quickly scan for changes and report their amount
Validate does change detection, along with datarot (silent data corruption)
Verify does bit for bit verification of the RAID

These commands are further described in the Snapshot RAID maintenance tutorial.


Scrolling below in that window, you will see the Restore section, which will allow you, when losing a DRU or a PPU, to restore its content if it is not beyond the fault tolerance of your configuration.

This process is further described in the Restore tutorial.



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7 Responses to “Expert Mode: Setting up your Snapshot RAID”

  1. brit November 13, 2011 at 12:29 AM #

    Were do i go from here did I set up the RAID were is the drive that I made in my computer.

  2. brit November 13, 2011 at 12:32 AM #

    And what is URU Iv looked all over this sight and cant find a explanation

  3. brit November 13, 2011 at 12:36 AM #

    And a nother thing ween i hit the help button in the top left nothing happens and y do we have to drag the drives in that little sweet spot in the white space i should be able to just drag and drop any were i mean its wide open

    • xliv November 15, 2011 at 4:08 AM #

      Please use the forum for asking question or suggesting improvements. URU is the Undo Risk Unit, allows you to undo an undesired update of your RAID. I don’t understand the other question – once you’ve setup your snapshot RAID, you can try a restore by simulating a failed DRU, as explained in the Restore tutorial. I don’t know what drive you’re looking for, if it’s the drive created by the Storage Pooling feature, then you’re looking to the wrong tutorial, have a look to the Storage Pool tutorial.

  4. Ed Baines December 3, 2011 at 11:32 AM #

    1) How do I calculate how big the URU should be? In my VMWare simulation, it can be smaller than any other disk. What limitation does a small URU place upon the functioning of FlexRaid?

    2) What function uses the URU? I could not find an undo undesired update button. Is this command line only?

    • xliv December 3, 2011 at 3:22 PM #

      It would be better to ask those questions in the forum, you’ll get more answers than here.

  5. Mr. H. August 5, 2012 at 3:12 AM #

    I just want a simple solution to mirror 1 external drive to another, something like a raid one set up. Can this software do this?!?!

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