Public bug reported: Using the backup operation from the interactive menu to produce the GPT information into a file I have spotted some duplicate entries in the first sectors of the disk regarding the EFI part. Using the dd utility to read the first 34 512B sectors of the disk that contain the same information we see a different output.
This is the information dumped by gdisk in hex format up to the first partition entry: 00000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 000001c0 01 00 ee fe ff ff 01 00 00 00 af 6d 70 74 00 00 |...........mpt..| 000001d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 000001f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 aa |..............U.| 00000200 45 46 49 20 50 41 52 54 00 00 01 00 5c 00 00 00 |EFI PART....\...| 00000210 4c ce 5a 3b 00 00 00 00 01 00 00 00 00 00 00 00 |L.Z;............| 00000220 af 6d 70 74 00 00 00 00 22 00 00 00 00 00 00 00 |.mpt....".......| 00000230 8e 6d 70 74 00 00 00 00 64 94 93 05 8b a7 19 4a |.mpt....d......J| 00000240 a3 43 25 8d 49 af 5a f5 02 00 00 00 00 00 00 00 |.C%.I.Z.........| 00000250 80 00 00 00 80 00 00 00 54 b1 bd 01 00 00 00 00 |........T.......| 00000260 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 00000400 45 46 49 20 50 41 52 54 00 00 01 00 5c 00 00 00 |EFI PART....\...| 00000410 ae 76 c7 98 00 00 00 00 af 6d 70 74 00 00 00 00 |.v.......mpt....| 00000420 01 00 00 00 00 00 00 00 22 00 00 00 00 00 00 00 |........".......| 00000430 8e 6d 70 74 00 00 00 00 64 94 93 05 8b a7 19 4a |.mpt....d......J| 00000440 a3 43 25 8d 49 af 5a f5 8f 6d 70 74 00 00 00 00 |.C%.I.Z..mpt....| 00000450 80 00 00 00 80 00 00 00 54 b1 bd 01 00 00 00 00 |........T.......| 00000460 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 00000600 28 73 2a c1 1f f8 d2 11 ba 4b 00 a0 c9 3e c9 3b |(s*......K...>.;| 00000610 b0 50 21 33 79 46 a1 4c bb 66 21 f1 91 08 19 ab |.P!3yF.L.f!.....| 00000620 00 08 00 00 00 00 00 00 ff 07 10 00 00 00 00 00 |................| 00000630 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| You can see the duplicate info between sectors 0x0200-0x0260 and 0x0400-0x0460. The same information produced by dd utility (dd if=/dev/sda of=/root/dump1 count=34 bs=512) 00000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 000001c0 01 00 ee fe ff ff 01 00 00 00 af 6d 70 74 00 00 |...........mpt..| 000001d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 000001f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 aa |..............U.| 00000200 45 46 49 20 50 41 52 54 00 00 01 00 5c 00 00 00 |EFI PART....\...| 00000210 4c ce 5a 3b 00 00 00 00 01 00 00 00 00 00 00 00 |L.Z;............| 00000220 af 6d 70 74 00 00 00 00 22 00 00 00 00 00 00 00 |.mpt....".......| 00000230 8e 6d 70 74 00 00 00 00 64 94 93 05 8b a7 19 4a |.mpt....d......J| 00000240 a3 43 25 8d 49 af 5a f5 02 00 00 00 00 00 00 00 |.C%.I.Z.........| 00000250 80 00 00 00 80 00 00 00 54 b1 bd 01 00 00 00 00 |........T.......| 00000260 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 00000400 28 73 2a c1 1f f8 d2 11 ba 4b 00 a0 c9 3e c9 3b |(s*......K...>.;| 00000410 b0 50 21 33 79 46 a1 4c bb 66 21 f1 91 08 19 ab |.P!3yF.L.f!.....| 00000420 00 08 00 00 00 00 00 00 ff 07 10 00 00 00 00 00 |................| 00000430 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 00000480 af 3d c6 0f 83 84 72 47 8e 79 3d 69 d8 47 7d e4 |.=....rG.y=i.G}.| 00000490 1a 08 44 4d ae 19 83 4b a9 27 ff 57 9a 89 d2 e1 |..DM...K.'.W....| 000004a0 00 08 10 00 00 00 00 00 ff 6f 71 73 00 00 00 00 |.........oqs....| 000004b0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 00000500 6d fd 57 06 ab a4 c4 43 84 e5 09 33 c8 4b 4f 4f |m.W....C...3.KOO| 00000510 18 7b 1b bc 57 22 6e 45 9b a9 81 22 a3 f4 e3 14 |.{..W"nE..."....| 00000520 00 70 71 73 00 00 00 00 ff 67 70 74 00 00 00 00 |.pqs.....gpt....| 00000530 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 00004400 As you can see the duplicate EFI information is missing and the GPT information starts on sector 0x0400 as it should. I am using GPT fdisk (gdisk) version 0.8.8 under Ubuntu Server 14.04. Thanks, Nick ** Affects: gdisk (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to gdisk in Ubuntu. https://bugs.launchpad.net/bugs/1367464 Title: Backup operation seems to be duplicating information To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gdisk/+bug/1367464/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs