1 2种分区结构简介
MBR分区
- 硬盘主引导记录MBR由4个部分组成
- 主引导程序（偏移地址0000H--0088H），它负责从活动分区中装载，并运行系统引导程序。
- 出错信息数据区，偏移地址0089H--00E1H为出错信息，00E2H--01BDH全为0字节。
- 分区表（DPT,Disk Partition Table）含4个分区项，偏移地
- 址01BEH--01FDH,每个分区表项长16个字节，共64字节为分区项1、分区项2、分区项3、分区项4
- 结束标志字，偏移地址01FE--01FF的2个字节值为结束标志55AA
GPT分区
- GPT:GUID（Globals Unique Identifiers） partitiontable 支持128个分区，使用64位，支持8Z（512Byte/block ）64Z （ 4096Byte/block）
- 使用128位UUID(Universally Unique Identifier) 表示磁盘和分区 GPT分区表自动备份在头和尾两份，并有CRC校验位
- UEFI (统一扩展固件接口)硬件支持GPT，使操作系统启动
2 fdisk的使用
2.1 fdisk命令的基础
[root@centos7 mnt]$ dd if=/dev/fdisk /dev/sdb Welcome to fdisk (util-linux 2.23.2). Changes will remain in memory only, until you decide to write them. Be careful before using the write command. Device does not contain a recognized partition table Building a new DOS disklabel with disk identifier 0xc0e6470d. Command (m for help): m Command action a toggle a bootable flag # 切换可启动标志 b edit bsd disklabel # 编辑磁盘标记 c toggle the dos compatibility flag # 切换dos兼容标志 d delete a partition # 删除一个分区 g create a new empty GPT partition table # 创建一个空的GPT分区表 G create an IRIX (SGI) partition table # 创建一个IRIX分区表 l list known partition types # 列出已知的分区类型 m print this menu # 打印菜单 n add a new partition # 添加一个分区 o create a new empty DOS partition table # 创建一个空的DOS分区表 p print the partition table # 打印分区表 q quit without saving changes # 退出不保存 s create a new empty Sun disklabel # 创建一个空的sun磁盘标签 t change a partition's system id # 改变一个分区的类型 u change display/entry units # 改变显示的单位 v verify the partition table # 验证分区表 w write table to disk and exit # 写分区表并退出 x extra functionality (experts only) # 高级功能 Command (m for help):
2.2 fdisk实战
例子： 使用fdisk工具给/dev/sdb（100G）分区满足下面几个要求
- 3个主分区一个扩展分区
- /dev/sdb1分区类型为Linux LVM，大小为30G
- /dev/sdb2分区类型为swap，大小为20G
- /dev/sdb3分区类型为Linux， 大小为10G
- /dev/sdb5分区类型为linux,大小为10G
- 保留40G留作后用
[root@centos7 mnt]$ fdisk /dev/sdb Welcome to fdisk (util-linux 2.23.2). Changes will remain in memory only, until you decide to write them. Be careful before using the write command. Device does not contain a recognized partition table Building a new DOS disklabel with disk identifier 0x2fd8d812. Command (m for help): n Partition type: p primary (0 primary, 0 extended, 4 free) e extended Select (default p): p Partition number (1-4, default 1): First sector (2048-209715199, default 2048): Using default value 2048 Last sector, +sectors or +size{K,M,G} (2048-209715199, default 209715199): +30G Partition 1 of type Linux and of size 30 GiB is set Command (m for help): n Partition type: p primary (1 primary, 0 extended, 3 free) e extended Select (default p): p Partition number (2-4, default 2): First sector (62916608-209715199, default 62916608): Using default value 62916608 Last sector, +sectors or +size{K,M,G} (62916608-209715199, default 209715199): +20G Partition 2 of type Linux and of size 20 GiB is set Command (m for help): n Partition type: p primary (2 primary, 0 extended, 2 free) e extended Select (default p): p Partition number (3,4, default 3): First sector (104859648-209715199, default 104859648): Using default value 104859648 Last sector, +sectors or +size{K,M,G} (104859648-209715199, default 209715199): +10G Partition 3 of type Linux and of size 10 GiB is set Command (m for help): n Partition type: p primary (3 primary, 0 extended, 1 free) e extended Select (default e): e Selected partition 4 First sector (125831168-209715199, default 125831168): Using default value 125831168 Last sector, +sectors or +size{K,M,G} (125831168-209715199, default 209715199): Using default value 209715199 Partition 4 of type Extended and of size 40 GiB is set Command (m for help): n All primary partitions are in use Adding logical partition 5 First sector (125833216-209715199, default 125833216): Using default value 125833216 Last sector, +sectors or +size{K,M,G} (125833216-209715199, default 209715199): +10G Partition 5 of type Linux and of size 10 GiB is set Command (m for help): p Disk /dev/sdb: 107.4 GB, 107374182400 bytes, 209715200 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk label type: dos Disk identifier: 0x2fd8d812 Device Boot Start End Blocks Id System /dev/sdb1 2048 62916607 31457280 83 Linux /dev/sdb2 62916608 104859647 20971520 83 Linux /dev/sdb3 104859648 125831167 10485760 83 Linux /dev/sdb4 125831168 209715199 41942016 5 Extended /dev/sdb5 125833216 146804735 10485760 83 Linux Command (m for help): t Partition number (1-5, default 5): 1 Hex code (type L to list all codes): L 0 Empty 24 NEC DOS 81 Minix / old Lin bf Solaris 1 FAT12 27 Hidden NTFS Win 82 Linux swap / So c1 DRDOS/sec (FAT- 2 XENIX root 39 Plan 9 83 Linux c4 DRDOS/sec (FAT- 3 XENIX usr 3c PartitionMagic 84 OS/2 hidden C: c6 DRDOS/sec (FAT- 4 FAT16 <32M 40 Venix 80286 85 Linux extended c7 Syrinx 5 Extended 41 PPC PReP Boot 86 NTFS volume set da Non-FS data 6 FAT16 42 SFS 87 NTFS volume set db CP/M / CTOS / . 7 HPFS/NTFS/exFAT 4d QNX4.x 88 Linux plaintext de Dell Utility 8 AIX 4e QNX4.x 2nd part 8e Linux LVM df BootIt 9 AIX bootable 4f QNX4.x 3rd part 93 Amoeba e1 DOS access a OS/2 Boot Manag 50 OnTrack DM 94 Amoeba BBT e3 DOS R/O b W95 FAT32 51 OnTrack DM6 Aux 9f BSD/OS e4 SpeedStor c W95 FAT32 (LBA) 52 CP/M a0 IBM Thinkpad hi eb BeOS fs e W95 FAT16 (LBA) 53 OnTrack DM6 Aux a5 FreeBSD ee GPT f W95 Ext'd (LBA) 54 OnTrackDM6 a6 OpenBSD ef EFI (FAT-12/16/ 10 OPUS 55 EZ-Drive a7 NeXTSTEP f0 Linux/PA-RISC b 11 Hidden FAT12 56 Golden Bow a8 Darwin UFS f1 SpeedStor 12 Compaq diagnost 5c Priam Edisk a9 NetBSD f4 SpeedStor 14 Hidden FAT16 <3 61 SpeedStor ab Darwin boot f2 DOS secondary 16 Hidden FAT16 63 GNU HURD or Sys af HFS / HFS+ fb VMware VMFS 17 Hidden HPFS/NTF 64 Novell Netware b7 BSDI fs fc VMware VMKCORE 18 AST SmartSleep 65 Novell Netware b8 BSDI swap fd Linux raid auto 1b Hidden W95 FAT3 70 DiskSecure Mult bb Boot Wizard hid fe LANstep 1c Hidden W95 FAT3 75 PC/IX be Solaris boot ff BBT 1e Hidden W95 FAT1 80 Old Minix Hex code (type L to list all codes): 8e Changed type of partition 'Linux' to 'Linux LVM' Command (m for help): t Partition number (1-5, default 5): 2 Hex code (type L to list all codes): 82 Changed type of partition 'Linux' to 'Linux swap / Solaris' Command (m for help): p Disk /dev/sdb: 107.4 GB, 107374182400 bytes, 209715200 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk label type: dos Disk identifier: 0x2fd8d812 Device Boot Start End Blocks Id System /dev/sdb1 2048 62916607 31457280 8e Linux LVM /dev/sdb2 62916608 104859647 20971520 82 Linux swap / Solaris /dev/sdb3 104859648 125831167 10485760 83 Linux /dev/sdb4 125831168 209715199 41942016 5 Extended /dev/sdb5 125833216 146804735 10485760 83 Linux Command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. Syncing disks.