Converting Dynamic GPT disk to Basic GPT disk? (Non-destructively)
(Mod: please move this if I posted at the wrong forum, thanks!) Hi there, The setup of my machine: Disk 0: System disk on hardware RAID controller 0; RAID 5, 446 GB; MBR disk. Disk 1: Data disk on hardware RAID controller 1; RAID 5, 6TB; GPT disk. Both disks were basic until I recently reinstalled Windows 7 and made some adjustments to the boot order. The booting disk was originally set to disk 1 and now to disk 0. Therefore there is a 128MB reserved partition at the start of disk 1, that was set up by the previous installation. Since there is no purpose left for the 128MB partition I deleted it and extended the data partition over the unallocated space. For some reason Disk Management insists on converting entire disk 1 into a dynamic disk before extending the volume, and I was dumb enough to OK the operation. Now my disk 1 is a dynamic GPT disk. I want to convert it back to a basic GPT disk since I have Windows Image Backup stored on disk 1. According to a blog post by The Storage Team at Microsoft: http://blogs.technet.com/filecab/archive/2009/10/31/learn-more-about-system-image-backup.aspx "...a system image stored on a dynamic disk will provide limited functionality during restore. Specifically, the restore will be supported only if the partitioning on the source disk has not been changed. Therefore if your hard disk failed and is replaced with new hardware, you will not be able to restore the image." I need the ability to restore to a different hard disk. Now, I have done my homework before coming here. There is three ways to do this, as described by this article: http://www.dynamic-disk.com/convert-dynamic-disk-to-basic.html (1) Backup-Wipe-Convert-Restore; (2) By partition recovery software or hex editing; (3) Buy the software sold on the same website and let it do the conversion for you. My problem: (1) is not very practical as I have 5TB of data on disk 1 and I don't currently have the resource to procure a suitable backup device. (2) partition recovery can be messy and I'm not that desperate yet. I have experimented a lot with comparing and hex editing the partition table of disks with various layout (in virtual machines). The common "42 to 07" method does not work on GPT disks. (3) Judging from claim that the software supports single disk with maximum capacity of 2TB I assume it does not support GPT disks. After a few hours I think it might possible to revert disk 1 back to a basic disk through hex editing. I think all the partition data relating to dynamic/basic disk type is stored in sector 2 of the hard disk. Here is the data sector 2 of a dynamic GPT disk (as in HxD): Offset(h) 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F 00000000 AA C8 08 58 8F 7E E0 42 85 D2 E1 E9 04 34 CF B3 ªÈ.X.~àB…Òáé.4ϳ 00000010 B3 4F 49 DF CA 3E DF 11 A2 49 00 0C 29 6F C1 A7 ³OIßÊ>ß.¢I..)oÁ§ 00000020 22 00 00 00 00 00 00 00 21 08 00 00 00 00 00 00 ".......!....... 00000030 00 00 00 00 00 00 00 00 4C 00 44 00 4D 00 20 00 ........L.D.M. . 00000040 6D 00 65 00 74 00 61 00 64 00 61 00 74 00 61 00 m.e.t.a.d.a.t.a. 00000050 20 00 70 00 61 00 72 00 74 00 69 00 74 00 69 00 .p.a.r.t.i.t.i. 00000060 6F 00 6E 00 00 00 00 00 00 00 00 00 00 00 00 00 o.n............. 00000070 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000080 16 E3 C9 E3 5C 0B B8 4D 81 7D F9 2D F0 02 15 AE .ãÉã\.¸M.}ù-ð..® 00000090 36 9F 5C 22 40 42 BD 45 AA 92 7A CB DC 06 B7 3E 6Ÿ\"@B½Eª’zËÜ.·> 000000A0 22 08 00 00 00 00 00 00 21 00 04 00 00 00 00 00 ".......!....... 000000B0 00 00 00 00 00 00 00 00 4D 00 69 00 63 00 72 00 ........M.i.c.r. 000000C0 6F 00 73 00 6F 00 66 00 74 00 20 00 72 00 65 00 o.s.o.f.t. .r.e. 000000D0 73 00 65 00 72 00 76 00 65 00 64 00 20 00 70 00 s.e.r.v.e.d. .p. 000000E0 61 00 72 00 74 00 69 00 74 00 69 00 6F 00 6E 00 a.r.t.i.t.i.o.n. 000000F0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000100 A0 60 9B AF 31 14 62 4F BC 68 33 11 71 4A 69 AD `›¯1.bO¼h3.qJi. 00000110 B6 4F 49 DF CA 3E DF 11 A2 49 00 0C 29 6F C1 A7 ¶OIßÊ>ß.¢I..)oÁ§ 00000120 22 00 04 00 00 00 00 00 DE FF FF 04 00 00 00 00 ".......Þÿÿ..... 00000130 00 00 00 00 00 00 00 00 4C 00 44 00 4D 00 20 00 ........L.D.M. . 00000140 64 00 61 00 74 00 61 00 20 00 70 00 61 00 72 00 d.a.t.a. .p.a.r. 00000150 74 00 69 00 74 00 69 00 6F 00 6E 00 00 00 00 00 t.i.t.i.o.n..... And here is one from a basic GPT disk: Offset(d) 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 00000000 16 E3 C9 E3 5C 0B B8 4D 81 7D F9 2D F0 02 15 AE .ãÉã\.¸M.}ù-ð..® 00000016 FE C2 11 8A A8 8F B8 44 9F A7 16 BD A1 8B 04 5D þÂ.Š¨.¸DŸ§.½¡‹.] 00000032 22 00 00 00 00 00 00 00 21 00 04 00 00 00 00 00 ".......!....... 00000048 00 00 00 00 00 00 00 00 4D 00 69 00 63 00 72 00 ........M.i.c.r. 00000064 6F 00 73 00 6F 00 66 00 74 00 20 00 72 00 65 00 o.s.o.f.t. .r.e. 00000080 73 00 65 00 72 00 76 00 65 00 64 00 20 00 70 00 s.e.r.v.e.d. .p. 00000096 61 00 72 00 74 00 69 00 74 00 69 00 6F 00 6E 00 a.r.t.i.t.i.o.n. 00000112 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000128 A2 A0 D0 EB E5 B9 33 44 87 C0 68 B6 B7 26 99 C7 ¢ Ðëå¹3D‡Àh¶·&™Ç 00000144 7A 7C 1C 1C 3D 8B 47 4A 85 E1 49 0A CE F7 8D FE z|..=‹GJ…áI.Î÷.þ 00000160 00 08 04 00 00 00 00 00 FF F7 FF 04 00 00 00 00 ........ÿ÷ÿ..... 00000176 00 00 00 00 00 00 00 00 42 00 61 00 73 00 69 00 ........B.a.s.i. 00000192 63 00 20 00 64 00 61 00 74 00 61 00 20 00 70 00 c. .d.a.t.a. .p. 00000208 61 00 72 00 74 00 69 00 74 00 69 00 6F 00 6E 00 a.r.t.i.t.i.o.n. I think the key lies in this sector. However merely replacing the partition GUID does not work. There has to be an offset or a structural difference or something different between the two...I'm out of ideas and I need some sleep. I need someone who is familiar with the hard disk layout to tell me if this is possible or that I am dreaming too hard ;) So yeah, that's my first post here. Sorry for the wall of text. I just want to provide everything that I think would help.
April 3rd, 2010 12:00pm

GPT disk is widely used in Apple Computer. In Windows, MBR and GPT disk can are converted each other. I think it main advantage is that GPT disk can exceed the limitation of 2TB to allow a much larger volume than 2TB. Convert GPT Disk to MBR with windows disk manager
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May 25th, 2010 1:41pm

Unfortunately there is no way to convert it back directly, and I think I can recall a warning being displayed when converting to dynamic disk that this is the case. Here is what Microsoft say themselves: How to Convert a Dynamic Disk to a Basic Disk To change a dynamic disk back to a basic disk: Back up all the data on all the volumes on the disk you want to convert to a basic disk. Log on as Administrator or as a member of the Administrators group. Click Start, and then click Control Panel. Click Performance and Maintenance, click Administrative Tools, and then double-click Computer Management. In the left pane, click Disk Management. Right-click a volume on the dynamic disk that you want to change to a basic disk, and then click Delete Volume. Click Yes when you are prompted to delete the volume. Repeat steps 4 and 5 for each volume on the dynamic disk. After you have deleted all the volumes on the dynamic disk, right-click the dynamic disk that you want to change to a basic disk, and then click Convert to Basic Disk. NOTE:You must right-click the gray area that contains the disk title on the left side of the Details pane. For example, right-click Disk 1. As you can see the disk needs to be empty (contain no volumes) to be able to convert it back to a basic disk.
May 25th, 2010 2:16pm

Yeah, many people knows the fastest way to convert dynamic disk to basic disk without data loss. The special Dynamic Disk Converter, which can directly and safely finish the conversion.
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April 25th, 2011 6:14am

Dynamic Disk Converter, which i think could help you convert dynamic disk to basic without data losing.
September 13th, 2011 2:20pm

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