Publishing (starting) a Transparent RAID array

Pre-requisite

Creating a Transparent RAID array

System state prior to publishing the array

Transparent RAID arrays can easily be started and stopped at any time and without having to reboot the system.

Transparent RAID, in its core functionality, does not pool your drives into a single volume. Instead, Transparent RAID is focused on providing you with disks that behave completely independent of one another but where parity is computed and persisted transparently for recovery purposes.
Essentially, if you have 5 disks in your system that you would like to use in an array, it takes ownership of those 5 disks and spits out 5 transparent disks that substitute for the original disks.
Each transparent disk can be formatted and partitioned as if it was the original disk that backs it up.

The storage pooling feature is an optional feature that has been added to the core Transparent RAID functionality to provide you with a unified storage space.
You can use the transparent disks directly and even use them along side of the storage pool without the parity data being compromised. We recommend that you use only the storage pool for the unified data access aspect, but this is not a requirement. Rather, it is just a nicety. You can choose to only use the transparent disks with or without another storage pooling system, choose to use the storage pool only, or use them all (transparent disks and storage pool, in which case, caching must be disabled on the storage pool).

Transparent RAID runs inside the OS’s kernel. As such it is not necessary to stop the array before stopping the Web UI service or the service broker.
However, the storage pooling feature runs inside the service broker. So, stopping the service broker will stop the storage pool if it is running.

By default (when creating a new configuration), the array is not setup to auto-start.
The reason for this is to allow you to first configure the array and then set it to auto-start when everything is properly setup.
You can set the array to auto-start through the RAID options.

Now, let’s publish the array we initialized in the previous tutorial.

1. First, let’s look at the state of our test system after its initialization in the prior tutorial.
Here we see that every disk part of the array is marked as being offline (note disks 1, 2, & 4 – disks 3 and 5 were registered, but not added to an array and are still online).

Any disk marked as offline should never be brought back as online or else you will need to run the Verify/Sync operation on the array!

Placing the disks offline is part of the process of Transparent RAID system in taking ownership of the disks.
With disks 1 & 2 being offline, drive E and F are no longer shown in Windows Explorer and only drive G remains.
1. Array Disks in Offline mode

2. It is a good idea to take a peek at the default RAID options. The default options are the recommended options, but you should familiarize yourself with them for later topics. Most fields should have tooltips providing additional description.
To see the RAID options, click on the button shown below.
2. RAID Options Button
The RAID options will then be presented to you. The first set of options relate to the Transparent RAID system and the second set relate to the optional storage pool.
2. RAID Options

3. Click on the “Start” button to start the array.
If you left the RAID options at their defaults, a storage pool will also be published.
3. Start Array

4. A view of the panel after the array has been published.
4. Array Started

5. Below is a composite view showing 3 new disks added to the Windows Disk Manager (disks 6, 7, & 8).
Disks 6 & 7 are the transparent disks acting out as disks 1 & 2. Disk 8 is the storage pool disk.
Windows Explorer also shows drives E & F, which are now assigned to the transparent disks. Please note that, on most systems and by default, the volumes on the transparent disks will not be mounted (E & F should not be showing). If for whatever reason the volumes on the transparent disks are mounted, it is recommended that you remove the drive letters to restrict access to them as shown in the next section.
5. Transparent Disks

6. As recommended above, users should only use the storage pool and not the transparent disks.
If for whatever reason drive letters are added to the transparent disks, it is recommended that they are removed so that all data access is done through the pool.
If you wish to access the transparent disks along with the storage pool, it is imperative that you disable caching on the storage pool (by editing the RAID options).

To remove a drive letter off a volume, right-click on the volume in Windows Disk Manager, and choose “Change Drive Letter and Paths”. Then, select the drive letter or path to remove and click “Remove”.
6. Removing Drive Letters

7. The system is now ready for use through the storage pool.
7. Final

8. An important feature to note is that the storage pool can be started and stopped independently of the Transparent RAID array. You can start and stop the pool independently through the “Advanced Operations” menu.

The section below is no longer necessary starting with release 1.0 2013-12-24 if the storage pool is mounted as a fixed disk (note that by default, the pool disk is mounted as a removable disk – so, keep reading unless you have changed it to fixed disk). By design, Windows does not remember share settings on a removable disk after reboot!

Network shares created on the storage pool must be backed up in the Web UI so that they are restored the next time the storage pool is started.
This process is a workaround a known issue whereas shares created on the storage pool are not automatically reapplied by Windows on system reboot as noted above.
Backing up the shares configuration should be done anytime you make a change to the network shares settings on the storage pool drive.
8. Storage Pool Advanced Operations


What’s next?

Maintaining a Transparent RAID array

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One Response to “Publishing (starting) a Transparent RAID array”

  1. Skirge01 September 25, 2013 at 9:58 AM #

    I’m confused. The beginning of the article states:

    “You can choose to only use the transparent disks with or without another storage pooling system, choose to use the storage pool only, or use them all (transparent disks and storage pool, in which case, caching must be disabled on the storage pool).”

    But, the screenshot (2.-RAID-Options.png) of the default recommended RAID options seems to contradict that caching must be disabled because that screenshot shows “Enable Caching” set to TRUE.

    Am I misunderstanding the text instructions or is the screenshot wrong?

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