我们看看在Linux系统中磁盘是如何分区的
磁盘分区:
fdisk:是Linux的一个操作磁盘分区表的常用工具:
常用的格式:fdisk -l列出使用的磁盘设备
[root@linux ~]# fdisk -l
Disk /dev/sda: 214.7 GB, 214748364800 bytes, 419430400 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: 0x00029f42
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 1026047 512000 83 Linux
/dev/sda2 1026048 84912127 41943040 83 Linux
/dev/sda3 84912128 126855167 20971520 83 Linux
/dev/sda4 126855168 419430399 146287616 5 Extended
/dev/sda5 126859264 131055615 2098176 82 Linux swap / Solaris
下面我们根据实验一点点讲解Linux磁盘的管理操作
0.创建主分区(MBR):
a) Fdisk /dev/sda进入磁盘分区环境
[root@bogon ~]# 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):
当然,执行在这的时候,你可以使用m便会列出命令选项:
Command (m for help): m
Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
l list known partition types
m print this menu
n add a new partition
o create a new empty DOS partition table
p print the partition table
q quit without saving changes
s create a new empty Sun disklabel
t change a partition's system id
u change display/entry units
v verify the partition table
w write table to disk and exit
x extra functionality (experts only)
Command (m for help):
b) n 添加一个新的磁盘
Command (m for help): n
Command action
e extended
p primary partition (1-4)
e:表示扩展分区,p:表示主分区(1-4)
[延伸]我们之后主分区的数量是由分区表限制的,64的分区表最多只能分为4个主分区,或者三个主分区一个扩展分区或者其他,常见的window中的就是一个主分区一个扩展分区(明白了吗)
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 3
First cylinder (7859-15665, default 7859):
c) 回车选择默认的起始扇区
123 Partition number (1-4): 3
First cylinder (7859-15665, default 7859):
Using default value 7859
这里我们直接回车表示使用的是起始的柱面(在系统版本的不同,有的是根据柱面,有的是扇区,不过呢,也没啥大碍)
d) 输入格式为”+[M,G]”磁盘空间大小
1 Last cylinder, +cylinders or +size{K,M,G} (7859-15665, default 15665): +10G
根据我们自己个人定制,使用括号里面的单位,或者你也可以选择使用柱面表示,但是前面有一个加号
e) w保存退出
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: Device or resource busy.
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.
这一切的操作其实都是在内存中完成,只有使用w才是保存下来,下面我们来验证一下
f) ls /dev/sda*或者cat /proc/partitions查看是否有新创建的分区
[root@bogon ~]# ls /dev/sda*
/dev/sda /dev/sda1 /dev/sda2
[root@bogon ~]# cat /proc/partitions
major minor #blocks name
8 0 125829120 sda
8 1 204800 sda1
8 2 62914560 sda2
253 0 20971520 dm-0
253 1 2097152 dm-1
253 2 10485760 dm-2
253 3 20971520 dm-3
[root@bogon ~]#
奇怪,这是怎么回事呢?难道没有成功?不是的,这是因为没有同步到内核罢了
g) 执行parted –a/dev/sda一次或多次直到显示创建的新的分区
[root@bogon ~]# partx -a /dev/sda
BLKPG: Device or resource busy
error adding partition 1
BLKPG: Device or resource busy
error adding partition 2
[root@bogon ~]# 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
[root@bogon ~]# fdisk -l
Disk /dev/sda: 128.8 GB, 128849018880 bytes
255 heads, 63 sectors/track, 15665 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: 0x0004a6ba
Device Boot Start End Blocks Id System
/dev/sda1 * 1 26 204800 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 26 7859 62914560 8e Linux LVM
/dev/sda3 7859 9164 10489446 83 Linux
partx -a 其实就是通知(告诉)内核,磁盘信息变动了,你更新一下,一次没有显示,我们可以多执行一下看看结果,是不是10G的主分区就创建成功了。因此,这里特别留意两个命令partx 和fdisk
主分区我们创建了,可是我想创建一个交换分区,怎么创建呢?下面我们就来看看
大家知道swap分区就是内存空间,空间前后那就是不一样的了,我们先来查看一下内存空间
[root@bogon ~]# free -m
total used free shared buffers cached
Mem: 845 157 687 0 12 55
-/+ buffers/cache: 90 754
Swap: 2047 0 2047
现在开始创建一个swap分区
[root@bogon ~]# mkswap /dev/sda4
mkswap: /dev/sda4: warning: don't erase bootbits sectors
(dos partition table detected). Use -f to force.
Setting up swapspace version 1, size = 31463296 KiB
no label, UUID=c0c990f9-9d68-41d6-8e75-1eb41b08c4fc
[root@bogon ~]# mkswap -f /dev/sda4
Setting up swapspace version 1, size = 31463296 KiB
no label, UUID=5017d30a-1d96-4e47-b4ba-274d132afeb9
[root@bogon ~]# free -m
total used free shared buffers cached
Mem: 845 157 687 0 12 55
-/+ buffers/cache: 90 754
Swap: 2047 0 2047
[root@bogon ~]# swapon /dev/sda4
[root@bogon ~]# free -m
total used free shared buffers cached
Mem: 845 180 664 0 12 55
-/+ buffers/cache: 112 732
Swap: 32773 0 32773
[root@bogon ~]#
当然我们也是可以把一个已经创建的分区调整为swap分区
a) Fdisk /dev/sda进入磁盘分区环境
b) n 添加一个新的磁盘
c) 回车选择默认的起始扇区
d) 输入格式为”+[MG]”磁盘空间大小
e) l 显示调整分区的系统ID,swap(82)
f) t 调整分区
g) 输入调整的分区号
h) 输入要想调整的分区类型ID(82)
i) p 查看分区调整的结果
j) w 保存
k) kpartx -af /dev/sda重读一次或者两次,或者手动调整,使用kpartx –a /dev/sda#,#是调整的那个分区号,手动的添加一个分区
l) fdisk –l /dev/sda 查看显示是否成功
下面是源码展示:步骤很清楚
[root@bogon ~]# 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 (9165-13081, default 9165):
Using default value 9165
Last cylinder, +cylinders or +size{K,M,G} (9165-13081, default 13081): +100M
Command (m for help): 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
Command (m for help): t
Partition number (1-5): 5
Hex code (type L to list codes): 82
Changed system type of partition 5 to 82 (Linux swap / Solaris)
Command (m for help): p
Disk /dev/sda: 128.8 GB, 128849018880 bytes
255 heads, 63 sectors/track, 15665 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: 0x0004a6ba
Device Boot Start End Blocks Id System
/dev/sda1 * 1 26 204800 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 26 7859 62914560 8e Linux LVM
/dev/sda3 7859 9164 10489446 83 Linux
/dev/sda4 9165 13081 31463302+ 5 Extended
/dev/sda5 9165 9178 112423+ 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: Device or resource busy.
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.
[root@bogon ~]# kpartx -a /dev/sda
device-mapper: reload ioctl on sda1 failed: Invalid argument
create/reload failed on sda1
device-mapper: reload ioctl on sda2 failed: Invalid argument
create/reload failed on sda2
device-mapper: reload ioctl on sda3 failed: Invalid argument
create/reload failed on sda3
device-mapper: reload ioctl on sda4 failed: Invalid argument
create/reload failed on sda4
device-mapper: reload ioctl on sda5 failed: Invalid argument
create/reload failed on sda5
2.文件系统的创建
这里使用的是mkfs格式化工具,他可以把分区格式化为mkfs.cramfs mkfs.ext2 mkfs.ext3 mkfs.ext4 mkfs.ext4dev mkfs.msdos mkfs.vfat这些文件系统例如:
[root@bogon ~]# mkfs.ext4 /dev/sda3
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
655776 inodes, 2622361 blocks
131118 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=2688548864
81 block groups
32768 blocks per group, 32768 fragments per group
8096 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 37 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
a) mkfs.ext2 /dev/sda# 格式化sda#分区成为ext2的文件系统类型(破坏已有的文件系统类型)
[root@bogon ~]# mkfs.ext2 /dev/sda3
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
655776 inodes, 2622361 blocks
131118 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=2688548864
81 block groups
32768 blocks per group, 32768 fragments per group
8096 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632
Writing inode tables: done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 24 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
b) blkid /dev/sda# 查看分区是否格式化成目标文件系统类型
[root@bogon ~]# blkid /dev/sda3
/dev/sda3: UUID="228c109c-b9f8-4339-90eb-b072c60b3433" TYPE="ext2"
更多详情见请继续阅读下一页的精彩内容: http://www.linuxidc.com/Linux/2016-03/129297p2.htm