linux下磁盘分区方法详解

[root@docker ~]# fdisk -l      #找出机器中所有硬盘个数及设备名称Disk /dev/sda: 107.4 GB, 107374182400 bytes255 heads, 63 sectors/track, 13054 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x000aeeec   Device Boot      Start         End      Blocks   Id  System/dev/sda1   *           1        6375    51200000   83  Linux/dev/sda2            6375        7650    10240000   82  Linux swap / Solaris**fdisk -l 信息解析**(注意：Blocks的单位是byte)1、Disk /dev/sda: 107.4 GB, 107374182400 bytes块设备名称为/dev/sda，此设备的大小为107.4GB，107374182400 bytes这是转换成字节后的大小，即：107374182400/1024/1024/1024=100GB (注：bytes=B，表示“字节”，bit=b，表示“位”，所以1MB=1024KB,1KB=1024bytes)2、255 heads, 63 sectors/track, 13054 cylinders255 heads：表示磁头数为25563 sectors/track：表示每磁道上有63个扇区13054 cylinders：表示共有13054个柱面，柱面是分区的最小单位3、Units = cylinders of 16065 * 512 = 8225280 bytes16065=255*63 因为每一个磁头都是在同一个柱面的，63表示每个磁道上的扇区数量，这两个数的乘积表示一个柱面上的扇区数量；所以16065*512表示一个柱面的大小是8225280字节4、Sector size (logical/physical): 512 bytes / 512 bytes表示一个扇区的大小是512字节总结：所以一个磁盘大小=一个柱面大小*柱面的总数=磁头数量*每个磁道上的扇区数*一个扇区大小*柱面总数磁盘大小=8225280*13054=107374182400bytes=100GB=255*63*512*13054

注意：根据如上信息可知，/dev/sda硬盘还有40G剩余空间

一、磁盘分区：（SCSI硬盘最多能分15个分区，IDE硬盘最多能划分63个分区）
主分区+扩展分区最多只能划分四个，想要更多的分区的话，只能在扩展分区上划分逻辑分区

[root@docker ~]# fdisk /dev/sdaWARNING: 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): nCommand action   e   extended   p   primary partition (1-4)pPartition number (1-4): 3First cylinder (7650-13054, default 7650): Using default value 7650Last cylinder, +cylinders or +size{K,M,G} (7650-13054, default 13054): +1024MCommand (m for help): pDisk /dev/sda: 107.4 GB, 107374182400 bytes255 heads, 63 sectors/track, 13054 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x000aeeec   Device Boot      Start         End      Blocks   Id  System/dev/sda1   *           1        6375    51200000   83  Linux/dev/sda2            6375        7650    10240000   82  Linux swap / Solaris/dev/sda3            7650        7781     1059858+  83  LinuxCommand (m for help): nCommand action   e   extended   p   primary partition (1-4)eSelected partition 4First cylinder (7782-13054, default 7782): Using default value 7782Last cylinder, +cylinders or +size{K,M,G} (7782-13054, default 13054): Using default value 13054Command (m for help): pDisk /dev/sda: 107.4 GB, 107374182400 bytes255 heads, 63 sectors/track, 13054 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x000aeeec   Device Boot      Start         End      Blocks   Id  System/dev/sda1   *           1        6375    51200000   83  Linux/dev/sda2            6375        7650    10240000   82  Linux swap / Solaris/dev/sda3            7650        7781     1059858+  83  Linux/dev/sda4            7782       13054    42355372+   5  ExtendedCommand (m for help): nFirst cylinder (7782-13054, default 7782): Using default value 7782Last cylinder, +cylinders or +size{K,M,G} (7782-13054, default 13054): +10G      Command (m for help): pDisk /dev/sda: 107.4 GB, 107374182400 bytes255 heads, 63 sectors/track, 13054 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x000aeeec   Device Boot      Start         End      Blocks   Id  System/dev/sda1   *           1        6375    51200000   83  Linux/dev/sda2            6375        7650    10240000   82  Linux swap / Solaris/dev/sda3            7650        7781     1059858+  83  Linux/dev/sda4            7782       13054    42355372+   5  Extended/dev/sda5            7782        9087    10490413+  83  LinuxCommand (m for help):wThe 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 atthe next reboot or after you run partprobe(8) or kpartx(8)Syncing disks.注意：此处在之前的基础上，再添加了一个主分区和一个扩展分区，并在扩展分区上划分了一个逻辑分区p显示分区表；n添加新的分区；t改变分区系统格式；L可以显示所有系统格式；d删除分区；w保存退出；q不保存退出

2、同步磁盘

[root@docker ~]# partx -a /dev/sda     BLKPG: Device or resource busyerror adding partition 1BLKPG: Device or resource busyerror adding partition 2[root@docker ~]# partx -a /dev/sdaBLKPG: Device or resource busyerror adding partition 1BLKPG: Device or resource busyerror adding partition 2BLKPG: Device or resource busyerror adding partition 3BLKPG: Device or resource busyerror adding partition 4BLKPG: Device or resource busyerror adding partition 5[root@docker ~]# fdisk -lDisk /dev/sda: 107.4 GB, 107374182400 bytes255 heads, 63 sectors/track, 13054 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x000aeeec   Device Boot      Start         End      Blocks   Id  System/dev/sda1   *           1        6375    51200000   83  Linux/dev/sda2            6375        7650    10240000   82  Linux swap / Solaris/dev/sda3            7650        7781     1059858+  83  Linux/dev/sda4            7782       13054    42355372+   5  Extended/dev/sda5            7782        9087    10490413+  83  Linux注意：扩展分区不能格式化，也不需要挂载，扩展分区最好是把剩下的所有的空间值都给它

3、分区格式化

[root@docker ~]# mkfs.ext4 /dev/sda3mke2fs 1.41.12 (17-May-2010)文件系统标签=操作系统:Linux块大小=4096 (log=2)分块大小=4096 (log=2)Stride=0 blocks, Stripe width=0 blocks66384 inodes, 264964 blocks13248 blocks (5.00%) reserved for the super user第一个数据块=0Maximum filesystem blocks=2726297609 block groups32768 blocks per group, 32768 fragments per group7376 inodes per groupSuperblock backups stored on blocks:     32768, 98304, 163840, 229376正在写入inode表: 完成                            Creating journal (8192 blocks): 完成Writing superblocks and filesystem accounting information: 完成This filesystem will be automatically checked every 27 mounts or180 days, whichever comes first.  Use tune2fs -c or -i to override.

4、挂载分区

[root@docker ~]# df -ThFilesystem     Type   Size  Used Avail Use% Mounted on/dev/sda1      ext4    48G  4.4G   42G  10% /tmpfs          tmpfs  495M  192K  495M   1% /dev/shm[root@docker ~]# mkdir /luyun /hello[root@docker ~]# mount /dev/sda3 /luyun[root@docker ~]# mount /dev/sda5 /hello[root@docker ~]# df -ThFilesystem     Type   Size  Used Avail Use% Mounted on/dev/sda1      ext4    48G  4.4G   42G  10% /tmpfs          tmpfs  495M  192K  495M   1% /dev/shm/dev/sda3      ext4   987M  1.3M  918M   1% /luyun/dev/sda5      ext4   9.8G   23M  9.2G   1% /hello

二、交换分区

1、查看交换分区

[root@docker ~]# cat /proc/swaps Filename                Type        Size    Used    Priority/dev/sda2                               partition   10239996    11820   -1[root@docker ~]# swapon -sFilename                Type        Size    Used    Priority/dev/sda2                               partition   10239996    11820   -1

2、若交换分区不够用了，那如何添加交换分区

方法一

[root@docker ~]# fdisk /dev/sdaWARNING: 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): nFirst cylinder (9088-13054, default 9088): Using default value 9088Last cylinder, +cylinders or +size{K,M,G} (9088-13054, default 13054): +2GCommand (m for help): pDisk /dev/sda: 107.4 GB, 107374182400 bytes255 heads, 63 sectors/track, 13054 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x000aeeec   Device Boot      Start         End      Blocks   Id  System/dev/sda1   *           1        6375    51200000   83  Linux/dev/sda2            6375        7650    10240000   82  Linux swap / Solaris/dev/sda3            7650        7781     1059858+  83  Linux/dev/sda4            7782       13054    42355372+   5  Extended/dev/sda5            7782        9087    10490413+  83  Linux/dev/sda6            9088        9349     2104483+  83  LinuxCommand (m for help): t     #更改分区的类型为swapPartition number (1-6): 6Hex code (type L to list codes): L 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 b11  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 auto1b  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 FAT1Hex code (type L to list codes): 82Changed system type of partition 6 to 82 (Linux swap / Solaris)Command (m for help): p   Disk /dev/sda: 107.4 GB, 107374182400 bytes255 heads, 63 sectors/track, 13054 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x000aeeec   Device Boot      Start         End      Blocks   Id  System/dev/sda1   *           1        6375    51200000   83  Linux/dev/sda2            6375        7650    10240000   82  Linux swap / Solaris/dev/sda3            7650        7781     1059858+  83  Linux/dev/sda4            7782       13054    42355372+   5  Extended/dev/sda5            7782        9087    10490413+  83  Linux/dev/sda6            9088        9349     2104483+  82  Linux swap / SolarisCommand (m for help): wThe 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 atthe next reboot or after you run partprobe(8) or kpartx(8)Syncing disks.

2、同步磁盘

[root@docker ~]# partx -a /dev/sda     #此命令敲2次

3、分区格式化

[root@docker ~]# mkswap /dev/sda6Setting up swapspace version 1, size = 2104476 KiBno label, UUID=5c54d9bb-cded-477a-aba0-bd5cac82751f

4、激活swap分区

[root@docker ~]# swapon /dev/sda6

5、查看swap分区

[root@docker ~]# cat /proc/swaps Filename                Type        Size        Used    Priority/dev/sda2               partition   10239996    11820   -1/dev/sda6               partition   2104476     0       -2     

方法二

1、生成一个大文件，把这个文件所占用的空间变成交换分区

[root@docker ~]# dd if=/dev/zero of=file bs=1M count=100记录了100+0 的读入记录了100+0 的写出104857600字节(105 MB)已复制，2.35601 秒，44.5 MB/秒[root@docker ~]# ls -lh file -rw-r--r-- 1 root root 100M 9月  20 14:16 file[root@docker ~]# mkswap filemkswap: file: warning: don't erase bootbits sectors        on whole disk. Use -f to force.Setting up swapspace version 1, size = 102396 KiBno label, UUID=b3be4784-90fd-4e35-8d1a-9da079a3ec55[root@docker ~]# swapon file [root@docker ~]# cat /proc/swaps Filename                Type        Size        Used    Priority/dev/sda2               partition   10239996    12244   -1/dev/sda6               partition   2104476     0       -2/root/file              file        102396      0       -3

2、若想停用一个交换分区，如下

[root@docker ~]# swapoff /root/file [root@docker ~]# cat /proc/swaps Filename                Type        Size        Used    Priority/dev/sda2               partition   10239996    12244   -1/dev/sda6               partition   2104476     0       -2