Linux之fdisk命令

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圪蹴哈么 2021-11-12 11:26:21

文章标签 linux ide 分区表柱面 centos 文章分类 运维

Linux之fdisk命令

fdisk

fdisk [选项] <disk> 改变分区表

fdisk [选项] –l <disk> 列出所有分区表

fdisk –s <partition（分区编号）> 以分区块为单位，给出指定分区的大小

　　这是一个创建和维护分区的命令，兼容DOS类型的分区表、BSD或SUN类型的磁盘列表。注意fdisk不支持2T以上的硬盘分区，此时需要使用gdisk。

相关了解：

　　磁头数（Heads）表示硬盘有几个磁头，也就是有几面盘片，一个硬盘最多有255个磁头

　　柱面数（Cylinders）表示硬盘每面盘片上有几条磁道

　　扇区数（Sectors）表示每条磁道上有几个扇区，每条磁道最多有63个扇区

(1).选项

1 2 3 4 5 6	`-b <``size``> 指定扇区大小（512，1024，2048或4096 B）` `-c 关闭DOS兼容模式` `-u <``size``> 以扇区编号取代柱面编号来表示每个分区的起始地址，一般与-l选项联合使用` `-C <``number``> 指定柱面编号` `-H <``number``> 指定磁头编号` `-S <``number``> 指定磁道扇区编号`

(2).菜单操作说明：

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16	`a 设置可引导标记（活动分区/引导分区之间切换）` `b 编辑BSD磁盘标签` `c 设置DOS操作系统兼容标记（兼容/不兼容之间切换）` `d 删除一个分区` `l 显示已知的分区类型，其中82为Linux swap分区，83为Linux分区` `m 显示帮助信息` `n 增加一个新的分区` `o 创建一个新的空白的DOS分区表` `p 显示磁盘当前的分区表` `q 退出fdisk程序，不保存任何修改` `s 创建一个新的空白的Sun磁盘标签` `t 改变一个分区的系统ID，就是改变分区类型（比如把Linux Swap分区改为Linux分区）` `u 改变显示或输入单位` `v 验证磁盘分区表` `w 将分区表写入磁盘并退出（保存并退出）` `x 额外功能（专家级）`

(3).扩展

sda和hda的区别

1 2 3 4	`sd代表的是SCSI，SATA接口硬盘` `hd代表IDE接口的硬盘` `sda和hda最后面的a都代表的是第一块硬盘` `sda1和hda1则代表的是该硬盘的第一分区`

(4).实例

1）.使用-l选项，列出所有分区表

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50	`/盘/dev/sda:107.4G,107374182400字节（B）,255个磁头，63个扇区，13054柱面（磁道）` ` 1单位=16065柱面（磁道）512=8225280字节（B）` ` 扇区大小（逻辑/物理）：512字节（B）/512字节（B）` `输入/输出大小（最小/最佳）：512字节（B）/512字节（B）` `磁盘标识：0x00079700` `/` `Disk /dev/sda: 107.4 GB, 107374182400 bytes` `255 heads, 63 sectors/track, 13054 cylinders` `Units = cylinders of 16065 512 = 8225280 bytes` `Sector size (logical/physical): 512 bytes / 512 bytes` `I/O size (minimum/optimal): 512 bytes / 512 bytes` `Disk identifier: 0x00079700` `/设备　　　　　启动标识　　开始位置　结束位置　　分区块的大小　　分区ID　　系统（分区类型）`　 ` /dev/sda1　　*　　　　　1　　　　　64　　　　 512000　　　　 83　　　　Linux` `* 分区1不以柱面边界结束` `* /dev/sda2　　　　　　　　64　　　　13055　　　104344576　　 8e　　　　Linux LVM` `/` `Device Boot Start End Blocks Id System` `/dev/sda1 1 64 512000 83 Linux` `Partition 1 does not end` `on` `cylinder boundary.` `/dev/sda2 64 13055 104344576 8e Linux LVM` `Disk /dev/sdb: 21.5 GB, 21474836480 bytes` `255 heads, 63 sectors/track, 2610 cylinders` `Units = cylinders of 16065 * 512 = 8225280 bytes` `Sector size (logical/physical): 512 bytes / 512 bytes` `I/O size (minimum/optimal): 512 bytes / 512 bytes` `Disk identifier: 0x00000000` `Disk /dev/mapper/vg_centos6-lv_root: 53.7 GB, 53687091200 bytes` `255 heads, 63 sectors/track, 6527 cylinders` `Units = cylinders of 16065 * 512 = 8225280 bytes` `Sector size (logical/physical): 512 bytes / 512 bytes` `I/O size (minimum/optimal): 512 bytes / 512 bytes` `Disk identifier: 0x00000000` `Disk /dev/mapper/vg_centos6-lv_swap: 4194 MB, 4194304000 bytes` `255 heads, 63 sectors/track, 509 cylinders` `Units = cylinders of 16065 * 512 = 8225280 bytes` `Sector size (logical/physical): 512 bytes / 512 bytes` `I/O size (minimum/optimal): 512 bytes / 512 bytes` `Disk identifier: 0x00000000` `Disk /dev/mapper/vg_centos6-lv_home: 49.0 GB, 48964304896 bytes` `255 heads, 63 sectors/track, 5952 cylinders` `Units = cylinders of 16065 * 512 = 8225280 bytes` `Sector size (logical/physical): 512 bytes / 512 bytes` `I/O size (minimum/optimal): 512 bytes / 512 bytes` `Disk identifier: 0x00000000`

2）.使用-l和-u选项，用扇区编号取代柱面编号显示所有分区表

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39	`Disk /dev/sda: 107.4 GB, 107374182400 bytes` `255 heads, 63 sectors/track, 13054 cylinders, total 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 identifier: 0x00079700` `Device Boot Start End Blocks Id System` `/dev/sda1 * 2048 1026047 512000 83 Linux` `Partition 1 does not end on cylinder boundary.` `/dev/sda2 1026048 209715199 104344576 8e Linux LVM` `Disk /dev/sdb: 21.5 GB, 21474836480 bytes` `255 heads, 63 sectors/track, 2610 cylinders, total 41943040 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 identifier: 0x00000000` `Disk /dev/mapper/vg_centos6-lv_root: 53.7 GB, 53687091200 bytes` `255 heads, 63 sectors/track, 6527 cylinders, total 104857600 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 identifier: 0x00000000` `Disk /dev/mapper/vg_centos6-lv_swap: 4194 MB, 4194304000 bytes` `255 heads, 63 sectors/track, 509 cylinders, total 8192000 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 identifier: 0x00000000` `Disk /dev/mapper/vg_centos6-lv_home: 49.0 GB, 48964304896 bytes` `255 heads, 63 sectors/track, 5952 cylinders, total 95633408 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 identifier: 0x00000000`

3）.你们也看到了，我的/dev/sdb还没有开始使用，下面就用这个硬盘简单的演示下fdisk主要用到的操作菜单

　　1.在操作菜单下，创建一个新的分区

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60	`[root@CentOS6 桌面]# fdisk /dev/sdb` `Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel` `Building a` `new` `DOS disklabel with disk identifier 0xe8517189.` `Changes will remain` `in` `memory only, until you decide to write them.` `After that, of course, the previous content won't be recoverable.` `Warning: invalid flag 0x0000 of partition table 4 will be corrected` `by` `w(rite)` `WARNING: DOS-compatible mode` `is` `deprecated. It's strongly recommended to` `switch` `off the mode (command` `'c'``) and change display units to` `sectors (command` `'u'``).` `Command (m` `for` `help): n` `Command action` `e extended`　　　　　　　　　　　　`//扩展分区，创建扩展分区会占用一个主分区，并且只有创建扩展分区后才能创建逻辑分区` `p primary partition (1-4)`　　　`//主分区，最多创建4个` `e` `Partition number (1-4): 1` `First cylinder (1-2610,` `default` `1):` 　　`//起始柱面，默认为1` `Using` `default` `value 1` `Last cylinder, +cylinders or +size{K,M,G} (1-2610,` `default` `2610):` 　　`//终止柱面，默认为最后一个数` `Using` `default` `value 2610` `Command (m` `for` `help): n` `Command action` `l logical (5 or over)`　　　　`//逻辑分区` `p primary partition (1-4)`　 `//主分区` `l` `First cylinder (1-2610,` `default` `1): 1` `Last cylinder, +cylinders or +size{K,M,G} (1-2610,` `default` `2610): +10G`　　`//终止柱面不仅可以用柱面数表示，还可以用+[数值][单位]的格式表示` `Command (m` `for` `help): n` `Command action` `l logical (5 or over)` `p primary partition (1-4)` `l` `First cylinder (1307-2610,` `default` `1307):` `Using` `default` `value 1307` `Last cylinder, +cylinders or +size{K,M,G} (1307-2610,` `default` `2610):` `Using` `default` `value 2610` `Command (m` `for` `help): p` `Disk /dev/sdb: 21.5 GB, 21474836480 bytes` `255 heads, 63 sectors/track, 2610 cylinders` `Units = cylinders of 16065 * 512 = 8225280 bytes` `Sector size (logical/physical): 512 bytes / 512 bytes` `I/O size (minimum/optimal): 512 bytes / 512 bytes` `Disk identifier: 0xe8517189` `Device Boot Start End Blocks Id System` `/dev/sdb1 1 2610 20964793+ 5 Extended` `/dev/sdb5 1 1306 10490382 83 Linux` `/dev/sdb6 1307 2610 10474348+ 83 Linux` `Command (m` `for` `help): w`　　　　　　`//写入磁盘，保存并退出，否则之前的操作都无效。如果不想写入磁盘就使用q` `The partition table has been altered!` `Calling ioctl() to re-read partition table.` `Syncing disks.`

　　2.在操作菜单下，删除一个分区

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41	`[root@CentOS6 桌面]# fdisk /dev/sdb` `WARNING: DOS-compatible mode is deprecated. It's strongly recommended to` `switch off the mode (command 'c') and change display units to` `sectors (command 'u').` `Command (m for help): p` `Disk /dev/sdb: 21.5 GB, 21474836480 bytes` `255 heads, 63 sectors/track, 2610 cylinders` `Units = cylinders of 16065 * 512 = 8225280 bytes` `Sector size (logical/physical): 512 bytes / 512 bytes` `I/O size (minimum/optimal): 512 bytes / 512 bytes` `Disk identifier: 0xe8517189` `Device Boot Start End Blocks Id System` `/dev/sdb1 1 2610 20964793+ 5 Extended` `/dev/sdb5 1 1306 10490382 83 Linux` `/dev/sdb6 1307 2610 10474348+ 83 Linux` `Command (m for help): d` `Partition number (1-6): 6　　//这里输入的始分区编号，如果删除扩展分区，那扩展分区下的逻辑分区也会被删除` `Command (m for help): p` `Disk /dev/sdb: 21.5 GB, 21474836480 bytes` `255 heads, 63 sectors/track, 2610 cylinders` `Units = cylinders of 16065 * 512 = 8225280 bytes` `Sector size (logical/physical): 512 bytes / 512 bytes` `I/O size (minimum/optimal): 512 bytes / 512 bytes` `Disk identifier: 0xe8517189` `Device Boot Start End Blocks Id System` `/dev/sdb1 1 2610 20964793+ 5 Extended` `/dev/sdb5 1 1306 10490382 83 Linux` `Command (m for help): w` `The partition table has been altered!` `Calling ioctl() to re-read partition table.` `Syncing disks.`

3.在操作菜单下，修改分区类型

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58	`WARNING: DOS-compatible mode is deprecated. It's strongly recommended to` `switch off the mode (command 'c') and change display units to` `sectors (command 'u').` `Command (m for help): t` `Partition number (1-5): 5　　//操作哪一个分区` `Hex code (type L to list codes): L　　//这里会提示你使用L查看类型列表` `0 Empty 24 NEC DOS 81 Minix / old Lin bf Solaris` `1 FAT12 39 Plan 9 82 Linux swap / So c1 DRDOS/sec (FAT-` `2 XENIX root 3c PartitionMagic 83 Linux c4 DRDOS/sec (FAT-` `3 XENIX usr 40 Venix 80286 84 OS/2 hidden C: c6 DRDOS/sec (FAT-` `4 FAT16 <32M 41 PPC PReP Boot 85 Linux extended c7 Syrinx` `5 Extended 42 SFS 86 NTFS volume set da Non-FS data` `6 FAT16 4d QNX4.x 87 NTFS volume set db CP/M / CTOS / .` `7 HPFS/NTFS 4e QNX4.x 2nd part 88 Linux plaintext de Dell Utility` `8 AIX 4f QNX4.x 3rd part 8e Linux LVM df BootIt` `9 AIX bootable 50 OnTrack DM 93 Amoeba e1 DOS access` `a OS/2 Boot Manag 51 OnTrack DM6 Aux 94 Amoeba BBT e3 DOS R/O` `b W95 FAT32 52 CP/M 9f BSD/OS e4 SpeedStor` `c W95 FAT32 (LBA) 53 OnTrack DM6 Aux a0 IBM Thinkpad hi eb BeOS fs` `e W95 FAT16 (LBA) 54 OnTrackDM6 a5 FreeBSD ee GPT` `f W95 Ext'd (LBA) 55 EZ-Drive a6 OpenBSD ef EFI (FAT-12/16/` `10 OPUS 56 Golden Bow a7 NeXTSTEP f0 Linux/PA-RISC b` `11 Hidden FAT12 5c Priam Edisk a8 Darwin UFS f1 SpeedStor` `12 Compaq diagnost 61 SpeedStor a9 NetBSD f4 SpeedStor` `14 Hidden FAT16 <3 63 GNU HURD or Sys ab Darwin boot f2 DOS secondary` `16 Hidden FAT16 64 Novell Netware af HFS / HFS+ fb VMware VMFS` `17 Hidden HPFS/NTF 65 Novell Netware b7 BSDI fs fc VMware VMKCORE` `18 AST SmartSleep 70 DiskSecure Mult b8 BSDI swap fd Linux raid auto` `1b Hidden W95 FAT3 75 PC/IX bb Boot Wizard hid fe LANstep` `1c Hidden W95 FAT3 80 Old Minix be Solaris boot ff BBT` `1e Hidden W95 FAT1` `Hex code (type L to list codes): b` `Changed system type of partition 5 to b (W95 FAT32)` `Command (m for help): p　　//可以看到由原来的Linux改成了W95 FAT32` `Disk /dev/sdb: 21.5 GB, 21474836480 bytes` `255 heads, 63 sectors/track, 2610 cylinders` `Units = cylinders of 16065 * 512 = 8225280 bytes` `Sector size (logical/physical): 512 bytes / 512 bytes` `I/O size (minimum/optimal): 512 bytes / 512 bytes` `Disk identifier: 0xe8517189` `Device Boot Start End Blocks Id System` `/dev/sdb1 1 2610 20964793+ 5 Extended` `/dev/sdb5 1 1306 10490382 b W95 FAT32` `Command (m for help): w` `The partition table has been altered!` `Calling ioctl() to re-read partition table.` `WARNING: If you have created or modified any DOS 6.x` `partitions, please see the fdisk manual page for additional` `information.` `Syncing disks.`

4）.对正在使用的磁盘，再次进行分区时会出现以下提示

1 2 3	`WARNING: Re-reading the partition table failed with error 16: 设备或资源忙.` `The kernel still uses the old table. The` `new` `table will be used at` `the next reboot or after you run partprobe(8) or kpartx(8)`

　　注意此时分区并不会立刻生效，可以重启系统，也可以使用提示的命令partprobe或kpartx。

　　下面展示完整情况内容

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32	`[root@xuexi ~]# fdisk /dev/sdb` `欢迎使用 fdisk (util-linux 2.23.2)。` `更改将停留在内存中，直到您决定将更改写入磁盘。` `使用写入命令前请三思。` `命令(输入 m 获取帮助)：n`　　`//新建分区` `Partition type:` `p primary (1 primary, 0 extended, 3 free)` `e extended` `Select (``default` `p): p`　　`//创建主分区` `分区号 (2-4，默认 2)：` `起始扇区 (2099200-4194303，默认为 2099200)：` `将使用默认值 2099200` `Last 扇区, +扇区 or +size{K,M,G} (2099200-4194303，默认为 4194303)：` `将使用默认值 4194303` `分区 2 已设置为 Linux 类型，大小设为 1023 MiB` `命令(输入 m 获取帮助)：w`　　`//写入磁盘` `The partition table has been altered!` `Calling ioctl() to re-read partition table.` `WARNING: Re-reading the partition table failed with error 16: 设备或资源忙.` `The kernel still uses the old table. The` `new` `table will be used at` `the next reboot or after you run partprobe(8) or kpartx(8)` `正在同步磁盘。` `[root@xuexi ~]# ls /dev/sdb` `/dev/sdb /dev/sdb1` `[root@xuexi ~]# partprobe /dev/sdb`　　`//通知操作系统分区表已更改` `[root@xuexi ~]# ls /dev/sdb` `/dev/sdb /dev/sdb1 /dev/sdb2`