RAID, LDM, Dynamic Disk Support in HDM

Backup and restore specifics for real RAID arrays

RAID controller creates synthetic “hard disk” (better call it LUN, Logical Unit) and hides original physical disks.
So there is nothing special for Paragon engine to support here – the controller is doing all the trick, we see the resulting LUN and treat it as regular hard disk. Even if it's mirror RAID, we do make only one copy of data, and all implementation of redundancy or RAID array blocks distribution is performed on lower level than Windows gets it from BIOS (unlike dynamic disks).

In general, there are no special preparations the user should do to perform bare metal recovery to hardware RAID. The only case is some new RAID controller device which is not known to Windows or Windows ADK/WinRE, and customer should “load driver” to see RAID correctly. If Windows is restored from other hardware to such RAID LUN (making it bootable), then P2P adjust (Find and Adjust OS) wizard may sometimes be required to inject RAID controller driver into restored Windows OS.

When using cheap RAID controllers (such as built-in motherboard ones), if something is wrong with the physical disks, RAID controller can misbehave. Instead of informing the user, it might often silently decompose RAID for mirror setups (because it can be done without data loss) leading to two absolutely identical disks in Windows. Then Windows updates disk Id of the second disk silently and everything goes on as there is no trouble (but RAID is no longer enabled).
In such situations, Paragon engine can help in detecting the problem, because Windows provides the identical volume identifiers for two volumes on different disks, and something should be done to resolve this conflict.
But it depends on situation. For example, other software may change volume identifier without asking to avoid possible conflicts.

Backup specifics for “Dynamic Disks”

Dynamic disks are a proprietary extension to MBR and GPT disk partitioning layouts. The technology is owned by Microsoft. It’s not sufficiently documented and can’t be properly supported by third party vendors like us.

Dynamic disks are not logically integral entities. After converting basic disk into dynamic it becomes a part of something bigger – the LDM group. So there is no correct way to back up “dynamic disk”, only dynamic volumes of LDM group can be protected, because only volumes ("drives" with drive letters) are logically consistent objects here, even if all volumes are “simple” and no advantages of LDM are used (no mirrors, spanned or stripe volumes).

Dynamic MBR Disk can be converted to a Basic MBR Disk with the Windows Disk Management (WDM, diskmgmt.msc), but all volumes (partitions) on the disk have to be removed.

Paragon products detect dynamic disks layout and process it.

Note: Dynamic GPT is NOT supported at all!

Support for MS Dynamic Disks is very limited. The following operations are possible:

• View Layout
• Format Volume
• Back up Volume
• Restore/Restore with Autoresize
• Convert to Basic MBR (ONLY simple volumes – NO spanned, striped, mirrored, etc.)
• Wipe/Clear Free Space
• Compact MFT
• Test Surface
• Check FS
• Edit/View Sectors

Currently it’s not possible to Copy/Migrate dynamic disks.

HDM's Bare Metal Restore capabilities for dynamic disk backups:

Paragon engine supports restore of dynamic volumes the following three ways:

1. Restore to empty disk or completely overwriting destination disk layout.
   Original dynamic disk layout will be restored.
   If destination disks are of larger capacity, it will be processed too: dynamic LUN capacity (not volume) will be increased after restore automatically. Then user can extend volumes via Windows Disk Management Console (diskmgmt.msc), if needed.
2. Restore selected dynamic volumes from backup archive to original location.
   Original dynamic disks layout must be present! If it was modified or corrupted, this will not be possible.
3. Restore selected dynamic volumes from backup archive to any location as regular (not dynamic) volumes. Disks with no Dynamic flag are required.