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 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: 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 cylinders
255 heads：表示磁头数为255
63 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 bytes
16065=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/sda
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
p primary partition (1-4)
p
Partition number (1-4): 3
First cylinder (7650-13054, default 7650):
Using default value 7650
Last cylinder, +cylinders or +size{K,M,G} (7650-13054, default 13054): +1024M
Command (m for help): p
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: 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
Command (m for help): n
Command action
e extended
p primary partition (1-4)
e
Selected partition 4
First cylinder (7782-13054, default 7782):
Using default value 7782
Last cylinder, +cylinders or +size{K,M,G} (7782-13054, default 13054):
Using default value 13054
Command (m for help): p
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: 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
Command (m for help): n
First cylinder (7782-13054, default 7782):
Using default value 7782
Last cylinder, +cylinders or +size{K,M,G} (7782-13054, default 13054): +10G
Command (m for help): p
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: 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
Command (m for help):w
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)
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 busy
error adding partition 1
BLKPG: Device or resource busy
error adding partition 2
[root@docker ~]# partx -a /dev/sda
BLKPG: Device or resource busy
error adding partition 1
BLKPG: Device or resource busy
error adding partition 2
BLKPG: Device or resource busy
error adding partition 3
BLKPG: Device or resource busy
error adding partition 4
BLKPG: Device or resource busy
error adding partition 5
[root@docker ~]# fdisk -l
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: 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/sda3
mke2fs 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 blocks
66384 inodes, 264964 blocks
13248 blocks (5.00%) reserved for the super user
第一个数据块=0
Maximum filesystem blocks=272629760
9 block groups
32768 blocks per group, 32768 fragments per group
7376 inodes per group
Superblock 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 or
180 days, whichever comes first. Use tune2fs -c or -i to override.4、挂载分区
[root@docker ~]# df -Th
Filesystem 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 -Th
Filesystem 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 -s
Filename Type Size Used Priority
/dev/sda2 partition 10239996 11820 -12、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/sda
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
First cylinder (9088-13054, default 9088):
Using default value 9088
Last cylinder, +cylinders or +size{K,M,G} (9088-13054, default 13054): +2G
Command (m for help): p
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: 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 Linux
Command (m for help): t #更改分区的类型为swap
Partition number (1-6): 6
Hex 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 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): 82
Changed system type of partition 6 to 82 (Linux swap / Solaris)
Command (m for help): p
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: 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 / Solaris
Command (m for help): w
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)
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/sda6
Setting up swapspace version 1, size = 2104476 KiB
no label, UUID=5c54d9bb-cded-477a-aba0-bd5cac82751f4、激活swap分区
[root@docker ~]# swapon /dev/sda65、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 file
mkswap: file: warning: don't erase bootbits sectors
on whole disk. Use -f to force.
Setting up swapspace version 1, size = 102396 KiB
no 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 -32、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