RAID recovery with UFS Explorer

UFS Explorer, Professional Recovery can virtually assemble disassembled or crashed RAID arrays and recover data from there.
If you RAID controller was gone bad or some disk in Striped RAID got bad sector, usually it's hard to recover data from disks that were in RAID, especially in case of striped RAID (RAID 0, RAID 5, RAID 6 or their variations, like RAID 0+1 etc.). UFS Explorer, Professional Recovery allows you virtually re-construct RAID array and recover data from there. Now it supports:

	Highpoint controller based RAID arrays (with geometry auto-detection);
	Promise controller based RAID arrays (with geometry auto-detection); it is experimental;
	Most RAID controllers with no geometry descriptors (like nVidia SATA RAID, NAS RAIDs etc.).

Along with data recovery from hardware RAID arrays on entire physical disks, UFS Explorer, Professional Recovery supports data recovery from software and hardware RAID arrays, created on individual disk partitions.


Figure 1 shows builder mode choice window. It appears after you click 'Build RAID' icon and before actual RAID builder main window.


RAID reconstruction

To reconstruct your RAID array, do the following steps:

1. Precise RAID type and settings and do the following:
   • RAID 0 (Striped): Prepare and connect ALL disks (or disk image files), containing RAID data;
   • RAID 1 (Mirrored): You not need to reconstruct RAID. Just open FIRST drive in usual mode;
   • RAID 5 (Striping+Parity): Prepare and connect ALL disks (or disk image files), containing RAID data;
     
   • RAID 6 (Striping+Parity+GF Parity): Prepare and connect ALL disks (or disk image files), containing RAID data;
     
     Note: software also supports data recovery from degraded RAID5 and RAID6 arrays (with one missing disk) so if one of disks is gone bad, you should not connect it.
     
     
   • RAID 0 variations, like RAID 0+1 etc. (Striped+Mirrored): Prepare ALL disks, except mirror disks. Mirror disks contain the same information that ones they mirrors, so you need minimum set of working disks to assemble stripe-set;
   • JBOD (Spanned): Prepare and connect ALL disks (or disk image files), containing RAID data;
   
   
2. If some RAID parts are on disk image files, open these disk image files;
   
   
3. Click 'Build RAID array' button or choose this tool in 'Tools' menu;
   
   
4. Select RAID builder mode: 'Use etire disks' or 'Use disk partitions' (see Figure 1.); click 'Next'. UFS Explorer will display RAID builder main form.
   
   
   
   
   Figure 2. RAID builder (entire disks)
   
   Figure 2 shows RAID builder form for entire disks. Builder form for partitions has some differences, but has the same main controls.
   
   
5. Select with mouse recommended in p.1 disks (partitions) at left list and press 'Add >>' to move them to RAID (right panel);
   
   
6. If RAID was created with Promise or Highpoint controller, you may now just press 'Build' (you may try this option to verify RAID origin).
   
   
7. If your RAID was created with different controller type and just 'Build' states that no supported RAID descriptors detected, you have to:
   
   
   • Make sure that disks in list are in correct order (first one - at top);
     
     
   • Select RAID mode: Striping (for RAID 0/RAID 0+1/RAID 10/RAID 4), Spanning (JBOD) or Striping+Parity (RAID 5);
     
     
   • For degraded RAID5 array, be sure you added 'Virtual disk placeholder' for missing disk (with 'Add DPH >>' button);
     
     
   • For Striped RAID arrays (RAID 0, RAID 5, RAID 6 etc.) - select Stripe (or block) size as it was in controller settings;
     
     
   • For RAID 5 and RAID 6 arrays you must also select parity distribution algorithm: Left Symmetric (Backward Dynamic), Right Symmetric (Forward Dynamic), Left Asymmetric (Backward) or Right Asymmetric (Forward);
     
     Note: if you not sure about your RAID configuration or about terms, please refer to RAID controller manual, your records and RAID organization and recovery documents.
     
     
   • Now, press 'Build'.
   
   
8. On success, UFS Explorer, Professional Recovery will close 'constructor' dialog and will add new 'RAID' virtual device to left-side disks tree.
   
   

If you have more complex RAID array (Striping+Spaning, have reserved sectors at disk start or end), with RAID constructor you may:

• Construct striped parts separately to Virtual RAIDs and then combine (span) set of such striped Virtual RAIDs to one;
• Specify additional parameters for reselved sectors (These parameters are required rarely and only in case you sure there are controller-reserved disk space, so in general you shouldn't modify zero defaults).

UFS Explorer, Professional Recovery does many RAID consistency checks, however it may miss some construction problems, especially disks-order related in case of manual reconstruction; so if it can not read your RAID, try to reconstruct it with different disk order or settings.


Requirements

OS:	Windows 2000/XP/2003/Vista
Client Software:	UFS Explorer Professional Recovery
File system:	ALL

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See also: RAW recovey, Data Access, Help topics.