ディスク先頭のGPTを解析する時に、基本知識として知っておくべき構造
MBR ： ディスクの0セクタ目
MBRはディスクの最初のセクタ（セクタ=0）の1セクタ分（512Bytes）のサイズ
MBR
00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ================ 00000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000020 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000030 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000040 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000050 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000060 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000070 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000080 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00................ 00000090 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000000A0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000000B0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00................ 000000D0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000000E0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000000F0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000100 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000110 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000120 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000130 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000140 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000150 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000160 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000170 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000180 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000190 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000001A0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000001B0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000001C0 02 00 EE FF FF FF 01 00 00 00 AF 1A C8 6F 00 00 .............o.. 000001D0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000001E0 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. 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ================
MBR構造の凡例
0000 - 01BD : Master Bootstrap Loader, 446 bytes 01B8 - 01BB : Windows Disk Signature 01BE - 01CD : (MBR) Partition 1, 16 bytes 01BE : Boot Indicator (0x00=non boot, 0x80=boot) 01BF - 01C1 : Starting CHS, 3 bytes 01C2 : System ID (0xee=gpt, 0x07=ntfs, 0x0b,0x0c=fat32, 0x83=linux ...) 01C3 - 01C5 : Ending CHS, 3 bytes 01C6 - 01C9 : Starting LBA, 4 bytes 01CA - 01CD : Total Sectors, 4 bytes 01CE - 01DD : (MBR) Partition 2 01DE - 01ED : (MBR) Partition 3 01EE - 01FD : (MBR) Partition 4 01FE - 01FF : MBR Signature, End Marker 0x55 0xaa
GPTヘッダ ： ディスクの1セクタ目
GPTヘッダはMBRの次のセクタ（セクタ=1）の1セクタ分（512Bytes）のサイズ
GPTヘッダ
00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ================ 00000200 45 46 49 20 50 41 52 54 00 00 01 00 5C 00 00 00 EFI PART....\... 00000210 C8 63 AD 65 00 00 00 00 01 00 00 00 00 00 00 00 .c.e............ 00000220 AF 1A C8 6F 00 00 00 00 22 00 00 00 00 00 00 00 ...o...."....... 00000230 8E 1A C8 6F 00 00 00 00 2C 89 2E 3B 6C 23 01 45 ...o....,..;l#.E 00000240 BF CA 84 08 D7 83 9C 3B 02 00 00 00 00 00 00 00 .......;........ 00000250 80 00 00 00 80 00 00 00 50 43 7F 68 00 00 00 00 ........PC.h.... 00000260 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000270 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000280 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000290 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000002A0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000002B0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000002C0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000002D0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000002E0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000002F0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000300 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000310 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000320 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000330 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000340 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000350 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000360 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000370 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000380 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000390 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000003A0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000003B0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000003C0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000003D0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000003E0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000003F0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ================
GPTヘッダの凡例
GPT Header, 512 bytes (1 sector) 0200 - 0207 : Signature = EFI PART, 8 bytes 0208 - 020B : Revision (ver1.0=0x00 0x00 0x01 0x00), 4 bytes 020C - 020F : Header size (92 bytes=0x5c 0x00 0x00 0x00), 4 bytes 0210 - 0213 : Header CRC32, 4 bytes 0214 - 0217 : reserved, 4 bytes 0218 - 021F : My LBA (this GPT sector=0x01 0x00 ... 0x00), 8 bytes 0220 - 0227 : Alternate LBA (backup GPT, at last sector), 8 bytes 0228 - 022F : First Usable LBA, 8 bytes 0230 - 0237 : Last usable LBA, 8 bytes 0238 - 0247 : Disk GUID, 16 bytes 0248 - 024F : Partition Entries LBA (next of this GPT=0x02 0x00 ... 0x00), 8 bytes 0250 - 0253 : Number of Partition Entries, 4 bytes 0254 - 0257 : Size of a Single Partition Entry (default=0x80 0x00 0x00 0x00), 4 bytes 0258 - 025B : CRC32, 4 bytes 025C - 03FF : padding (0x00 ...)
Alternate LBA (backup GPT) = 6f c8 1a af （10進数で1875385007）にGPTのバックアップが格納されていることも、次のようにして確認できる
$ sudo dd if=/dev/sda bs=512 skip=1875385007 count=1 | od -Ax -tx1z 1+0 レコード入力 1+0 レコード出力 512 bytes copied, 3.1215e-05 s, 16.4 MB/s 000000 45 46 49 20 50 41 52 54 00 00 01 00 5c 00 00 00 >EFI PART....\...< 000010 5f 31 8b 61 00 00 00 00 af 1a c8 6f 00 00 00 00 >_1.a.......o....< 000020 01 00 00 00 00 00 00 00 22 00 00 00 00 00 00 00 >........".......< 000030 8e 1a c8 6f 00 00 00 00 2c 89 2e 3b 6c 23 01 45 >...o....,..;l#.E< 000040 bf ca 84 08 d7 83 9c 3b 8f 1a c8 6f 00 00 00 00 >.......;...o....< 000050 80 00 00 00 80 00 00 00 50 43 7f 68 00 00 00 00 >........PC.h....< 000060 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >................< * 000200
GPTパーティションエントリ ： ディスクの2セクタ目〜21セクタ目の計20セクタ分
GPTパーティションエントリは、1パーティションあたり128Bytes（0x80 Bytes）で、最大パーティション数128個（0x80 個）、合計 128*128=16,384Bytes（0x4000 Bytes）のサイズ。16,384Bytes/512Bytes=32セクタ（0x20 セクタ）分ある。
第1パーティションのデータ領域は、MBR, GPTヘッダ, GPTパーティションエントリの次、35セクタ目（0x23 セクタ目）からとなる。
GPTパーティションエントリ
00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ================ 00000400 28 73 2A C1 1F F8 D2 11 BA 4B 00 A0 C9 3E C9 3B (s*......K...>.; 00000410 C9 C8 63 82 B6 00 7E 45 A6 68 AC 71 6E 57 87 5B ..c...~E.h.qnW.[ 00000420 00 08 00 00 00 00 00 00 FF 27 08 00 00 00 00 00 .........'...... 00000430 01 00 00 00 00 00 00 00 45 00 46 00 00 00 00 00 ........E.F..... 00000440 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000450 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000460 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000470 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ================ 00000480 16 E3 C9 E3 5C 0B B8 4D 81 7D F9 2D F0 02 15 AE ....\..M.}.-.... 00000490 B1 4B D5 8E 61 65 4A 48 AA 2F 11 8E 82 4C 1C D8 .K..aeJH./...L.. 000004A0 00 28 08 00 00 00 00 00 FF A7 08 00 00 00 00 00 .(.............. 000004B0 00 00 00 00 00 00 00 00 4D 00 69 00 00 00 00 00 ........M.i..... 000004C0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000004D0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000004E0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000004F0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ================ 00000500 A2 A0 D0 EB E5 B9 33 44 87 C0 68 B6 B7 26 99 C7 ......3D..h..&.. 00000510 D9 84 28 56 99 6D D3 4C A1 0C BC 67 BE C7 31 13 ..(V.m.L...g..1. 00000520 00 A8 08 00 00 00 00 00 FF A7 08 0A 00 00 00 00 ................ 00000530 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000540 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000550 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000560 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000570 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ================ 00000580 A2 A0 D0 EB E5 B9 33 44 87 C0 68 B6 B7 26 99 C7 ......3D..h..&.. 00000590 C6 5A E9 E1 9E 01 11 44 B3 EB A9 FC FF DC 89 07 .Z.....D........ 000005A0 00 A8 08 0A 00 00 00 00 FF BF 27 0A 00 00 00 00 ..........'..... 000005B0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000005C0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000005D0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000005E0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000005F0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ================ 00000600 A2 A0 D0 EB E5 B9 33 44 87 C0 68 B6 B7 26 99 C7 ......3D..h..&.. 00000610 57 EC 45 49 13 50 B3 4B AD E4 B6 33 67 D6 39 46 W.EI.P.K...3g.9F 00000620 00 C0 27 0A 00 00 00 00 FF BF 27 0B 00 00 00 00 ..'.......'..... 00000630 00 00 00 00 00 00 00 00 42 00 61 00 73 00 69 00 ........B.a.s.i. 00000640 63 00 20 00 64 00 61 00 74 00 61 00 20 00 70 00 c. .d.a.t.a. .p. 00000650 61 00 72 00 74 00 69 00 74 00 69 00 6F 00 6E 00 a.r.t.i.t.i.o.n. 00000660 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000670 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ================ 00000680 A2 A0 D0 EB E5 B9 33 44 87 C0 68 B6 B7 26 99 C7 ......3D..h..&.. 00000690 B6 45 38 B1 27 4A FB 43 88 E2 7B 84 37 71 FF CD .E8.'J.C..{.7q.. 000006A0 00 C0 27 0B 00 00 00 00 FF BF 27 10 00 00 00 00 ..'.......'..... 000006B0 00 00 00 00 00 00 00 00 42 00 61 00 73 00 69 00 ........B.a.s.i. 000006C0 63 00 20 00 64 00 61 00 74 00 61 00 20 00 70 00 c. .d.a.t.a. .p. 000006D0 61 00 72 00 74 00 69 00 74 00 69 00 6F 00 6E 00 a.r.t.i.t.i.o.n. 000006E0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000006F0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ================ 00000700 A2 A0 D0 EB E5 B9 33 44 87 C0 68 B6 B7 26 99 C7 ......3D..h..&.. 00000710 5F 8B FC 3A 24 41 67 48 A2 D7 F2 16 6C 6A A9 C5 _..:$AgH....lj.. 00000720 00 C0 27 10 00 00 00 00 FF BF 27 15 00 00 00 00 ..'.......'..... 00000730 00 00 00 00 00 00 00 00 42 00 61 00 73 00 69 00 ........B.a.s.i. 00000740 63 00 20 00 64 00 61 00 74 00 61 00 20 00 70 00 c. .d.a.t.a. .p. 00000750 61 00 72 00 74 00 69 00 74 00 69 00 6F 00 6E 00 a.r.t.i.t.i.o.n. 00000760 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000770 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ================ 00000780 A2 A0 D0 EB E5 B9 33 44 87 C0 68 B6 B7 26 99 C7 ......3D..h..&.. 00000790 D7 87 D5 E9 28 EE A6 4D 84 D7 26 B9 DD 37 E4 23 ....(..M..&..7.# 000007A0 00 C0 27 15 00 00 00 00 FF BF 27 1A 00 00 00 00 ..'.......'..... 000007B0 00 00 00 00 00 00 00 00 42 00 61 00 73 00 69 00 ........B.a.s.i. 000007C0 63 00 20 00 64 00 61 00 74 00 61 00 20 00 70 00 c. .d.a.t.a. .p. 000007D0 61 00 72 00 74 00 69 00 74 00 69 00 6F 00 6E 00 a.r.t.i.t.i.o.n. 000007E0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000007F0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ================ 00000800 A2 A0 D0 EB E5 B9 33 44 87 C0 68 B6 B7 26 99 C7 ......3D..h..&.. 00000810 D2 3B 44 04 75 74 8D 48 B5 61 34 6D 81 87 4E DD .;D.ut.H.a4m..N. 00000820 00 C0 27 1A 00 00 00 00 FF BF A7 1C 00 00 00 00 ..'............. 00000830 00 00 00 00 00 00 00 00 42 00 61 00 73 00 69 00 ........B.a.s.i. 00000840 63 00 20 00 64 00 61 00 74 00 61 00 20 00 70 00 c. .d.a.t.a. .p. 00000850 61 00 72 00 74 00 69 00 74 00 69 00 6F 00 6E 00 a.r.t.i.t.i.o.n. 00000860 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000870 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ================ 00000880 A2 A0 D0 EB E5 B9 33 44 87 C0 68 B6 B7 26 99 C7 ......3D..h..&.. 00000890 CA C5 E4 94 B1 A9 55 4E 84 EF AC 90 A8 66 70 0C ......UN.....fp. 000008A0 00 C0 A7 1C 00 00 00 00 FF BF 67 39 00 00 00 00 ..........g9.... 000008B0 00 00 00 00 00 00 00 00 42 00 61 00 73 00 69 00 ........B.a.s.i. 000008C0 63 00 20 00 64 00 61 00 74 00 61 00 20 00 70 00 c. .d.a.t.a. .p. 000008D0 61 00 72 00 74 00 69 00 74 00 69 00 6F 00 6E 00 a.r.t.i.t.i.o.n. 000008E0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000008F0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ================ 00000900 A2 A0 D0 EB E5 B9 33 44 87 C0 68 B6 B7 26 99 C7 ......3D..h..&.. 00000910 E4 B1 F6 79 CB F0 FF 49 AB 65 DA 0E 9D FA 66 AD ...y...I.e....f. 00000920 00 C0 67 39 00 00 00 00 FF BF 27 56 00 00 00 00 ..g9......'V.... 00000930 00 00 00 00 00 00 00 00 42 00 61 00 73 00 69 00 ........B.a.s.i. 00000940 63 00 20 00 64 00 61 00 74 00 61 00 20 00 70 00 c. .d.a.t.a. .p. 00000950 61 00 72 00 74 00 69 00 74 00 69 00 6F 00 6E 00 a.r.t.i.t.i.o.n. 00000960 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000970 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ================ 00000980 AF 3D C6 0F 83 84 72 47 8E 79 3D 69 D8 47 7D E4 .=....rG.y=i.G}. 00000990 02 C7 37 E2 D5 21 C4 46 9E 2C 3E 0B 85 A5 39 C5 ..7..!.F.,>...9. 000009A0 00 C0 27 56 00 00 00 00 FF BF A7 6F 00 00 00 00 ..'V.......o.... 000009B0 00 00 00 00 00 00 00 00 42 00 61 00 73 00 69 00 ........B.a.s.i. 000009C0 63 00 20 00 64 00 61 00 74 00 61 00 20 00 70 00 c. .d.a.t.a. .p. 000009D0 61 00 72 00 74 00 69 00 74 00 69 00 6F 00 6E 00 a.r.t.i.t.i.o.n. 000009E0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 000009F0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ================ 00000A00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000A10 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000A20 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000A30 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000A40 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000A50 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000A60 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000A70 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ================ 00000A80 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000A90 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000AA0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000AB0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000AC0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000AD0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000AE0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00000AF0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 〜 中略 〜 000043F0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ================
GPTパーティションエントリの凡例
0400 - 047F : Partition Table 1, 92 bytes 0400 - 040F : Partition GUID, 16 bytes 0410 - 041F : Unique partition GUID, 16 bytes 0420 - 0427 : First LBA, 8 bytes 0428 - 042F : Last LBA, 8 bytes 0430 - 0437 : Attribute Flags, 8 bytes 0438 - 047F : Partition name, 72 bytes
バックアップ GPTパーティションエントリは、バックアップGPTヘッダの直前16kBytes（16*1024/512=32セクタ）なので、そこに格納されているのか次のように確認してみる
開始セクタは 1875385007 - 32 = 1875384975
$ sudo dd if=/dev/sda bs=512 skip=1875384975 count=1 | od -Ax -tx1z 1+0 レコード入力 1+0 レコード出力 512 bytes copied, 0.000442747 s, 1.2 MB/s 000000 28 73 2a c1 1f f8 d2 11 ba 4b 00 a0 c9 3e c9 3b >(s*......K...>.;< 000010 c9 c8 63 82 b6 00 7e 45 a6 68 ac 71 6e 57 87 5b >..c...~E.h.qnW.[< 000020 00 08 00 00 00 00 00 00 ff 27 08 00 00 00 00 00 >.........'......< 000030 01 00 00 00 00 00 00 00 45 00 46 00 00 00 00 00 >........E.F.....< 000040 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >................< * 000080 16 e3 c9 e3 5c 0b b8 4d 81 7d f9 2d f0 02 15 ae >....\..M.}.-....< 000090 b1 4b d5 8e 61 65 4a 48 aa 2f 11 8e 82 4c 1c d8 >.K..aeJH./...L..< 0000a0 00 28 08 00 00 00 00 00 ff a7 08 00 00 00 00 00 >.(..............< 0000b0 00 00 00 00 00 00 00 00 4d 00 69 00 00 00 00 00 >........M.i.....< 0000c0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >................< * 000100 a2 a0 d0 eb e5 b9 33 44 87 c0 68 b6 b7 26 99 c7 >......3D..h..&..< 000110 d9 84 28 56 99 6d d3 4c a1 0c bc 67 be c7 31 13 >..(V.m.L...g..1.< 000120 00 a8 08 00 00 00 00 00 ff a7 08 0a 00 00 00 00 >................< 000130 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >................< * 000180 a2 a0 d0 eb e5 b9 33 44 87 c0 68 b6 b7 26 99 c7 >......3D..h..&..< 000190 c6 5a e9 e1 9e 01 11 44 b3 eb a9 fc ff dc 89 07 >.Z.....D........< 0001a0 00 a8 08 0a 00 00 00 00 ff bf 27 0a 00 00 00 00 >..........'.....< 0001b0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >................< * 000200
テキスト形式でダンプする
$ sudo gdisk -l /dev/sda GPT fdisk (gdisk) version 1.0.3 Partition table scan: MBR: protective BSD: not present APM: not present GPT: present Found valid GPT with protective MBR; using GPT. Disk /dev/sda: 1875385008 sectors, 894.3 GiB Model: CSSD-S6B960CG3VX Sector size (logical/physical): 512/512 bytes Disk identifier (GUID): 3B2E892C-236C-4501-BFCA-8408D7839C3B Partition table holds up to 128 entries Main partition table begins at sector 2 and ends at sector 33 First usable sector is 34, last usable sector is 1875384974 Partitions will be aligned on 2048-sector boundaries Total free space is 2122349 sectors (1.0 GiB) Number Start (sector) End (sector) Size Code Name 1 2048 534527 260.0 MiB EF00 EF 2 534528 567295 16.0 MiB 0C01 Mi 3 567296 168339455 80.0 GiB 0700 4 168339456 170377215 995.0 MiB 0700 5 170377216 187154431 8.0 GiB 0700 Basic data partition 6 187154432 271040511 40.0 GiB 0700 Basic data partition 7 271040512 354926591 40.0 GiB 0700 Basic data partition 8 354926592 438812671 40.0 GiB 0700 Basic data partition 9 438812672 480755711 20.0 GiB 0700 Basic data partition 10 480755712 963100671 230.0 GiB 0700 Basic data partition 11 963100672 1445445631 230.0 GiB 0700 Basic data partition 12 1445445632 1873264639 204.0 GiB 8300 Basic data partition
$ sudo sfdisk --dump /dev/sda label: gpt label-id: 3B2E892C-236C-4501-BFCA-8408D7839C3B device: /dev/sda unit: sectors first-lba: 34 last-lba: 1875384974 /dev/sda1 : start= 2048, size= 532480, type=C12A7328-F81F-11D2-BA4B-00A0C93EC93B, uuid=8263C8C9-00B6-457E-A668-AC716E57875B, name="EF", attrs="RequiredPartition" /dev/sda2 : start= 534528, size= 32768, type=E3C9E316-0B5C-4DB8-817D-F92DF00215AE, uuid=8ED54BB1-6561-484A-AA2F-118E824C1CD8, name="Mi" /dev/sda3 : start= 567296, size= 167772160, type=EBD0A0A2-B9E5-4433-87C0-68B6B72699C7, uuid=562884D9-6D99-4CD3-A10C-BC67BEC73113 /dev/sda4 : start= 168339456, size= 2037760, type=EBD0A0A2-B9E5-4433-87C0-68B6B72699C7, uuid=E1E95AC6-019E-4411-B3EB-A9FCFFDC8907 /dev/sda5 : start= 170377216, size= 16777216, type=EBD0A0A2-B9E5-4433-87C0-68B6B72699C7, uuid=4945EC57-5013-4BB3-ADE4-B63367D63946, name="Basic data partition" /dev/sda6 : start= 187154432, size= 83886080, type=EBD0A0A2-B9E5-4433-87C0-68B6B72699C7, uuid=B13845B6-4A27-43FB-88E2-7B843771FFCD, name="Basic data partition" /dev/sda7 : start= 271040512, size= 83886080, type=EBD0A0A2-B9E5-4433-87C0-68B6B72699C7, uuid=3AFC8B5F-4124-4867-A2D7-F2166C6AA9C5, name="Basic data partition" /dev/sda8 : start= 354926592, size= 83886080, type=EBD0A0A2-B9E5-4433-87C0-68B6B72699C7, uuid=E9D587D7-EE28-4DA6-84D7-26B9DD37E423, name="Basic data partition" /dev/sda9 : start= 438812672, size= 41943040, type=EBD0A0A2-B9E5-4433-87C0-68B6B72699C7, uuid=04443BD2-7475-488D-B561-346D81874EDD, name="Basic data partition" /dev/sda10 : start= 480755712, size= 482344960, type=EBD0A0A2-B9E5-4433-87C0-68B6B72699C7, uuid=94E4C5CA-A9B1-4E55-84EF-AC90A866700C, name="Basic data partition" /dev/sda11 : start= 963100672, size= 482344960, type=EBD0A0A2-B9E5-4433-87C0-68B6B72699C7, uuid=79F6B1E4-F0CB-49FF-AB65-DA0E9DFA66AD, name="Basic data partition" /dev/sda12 : start= 1445445632, size= 427819008, type=0FC63DAF-8483-4772-8E79-3D69D8477DE4, uuid=E237C702-21D5-46C4-9E2C-3E0B85A539C5, name="Basic data partition"
