一、fdisk分區
1.使用fdisk -l查看新掛載的硬盤是否被識別
[root@Node2 test]# fdisk -l
Disk /dev/sda: 21.5 GB, 21474836480 bytes, 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 label type: dos
Disk identifier: 0x0008f184
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 1026047 512000 83 Linux
/dev/sda2 1026048 41943039 20458496 8e Linux LVM
Disk /dev/sdb: 1073 MB, 1073741824 bytes, 2097152 sectors
#在vmware中添加一塊1G的虛擬硬盤
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
2.新掛載硬盤分區方法
2.1 fdisk /dev/sdb
[root@Node2 ~]# fdisk /dev/sdb #使用fdisk命令對/dev/sdb進行分區
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 0x46480706.
Command (m for help): m #使用m幫助命令查看可輸入命令
Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
g create a new empty GPT partition table
G create an IRIX (SGI) partition table
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): p #打印輸出分區表
Disk /dev/sdb: 1073 MB, 1073741824 bytes, 2097152 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: 0x46480706
Device Boot Start End Blocks Id System
Command (m for help): n #添加新分區
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p): p #添加主分區，默認的分區格式是主分區
Partition number (1-4, default 1): 1 #分區號爲1
First sector (2048-2097151, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-2097151, default 2097151): +200M#可以採用+sectors或者+size的方式定義分區大小，這裏使用+200M這種方式定義分區大小，方便快捷
#定義分區的大小爲200M
Partition 1 of type Linux and of size 200 MiB is set
Command (m for help): p
Disk /dev/sdb: 1073 MB, 1073741824 bytes, 2097152 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: 0x46480706
Device Boot Start End Blocks Id System
/dev/sdb1 2048 411647 204800 83 Linux#分配第一個主分區成功
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): 2
First sector (411648-2097151, default 411648):
Using default value 411648
Last sector, +sectors or +size{K,M,G} (411648-2097151, default 2097151): +200M
Partition 2 of type Linux and of size 200 MiB is set
Command (m for help): p
Disk /dev/sdb: 1073 MB, 1073741824 bytes, 2097152 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: 0x46480706
Device Boot Start End Blocks Id System
/dev/sdb1 2048 411647 204800 83 Linux
/dev/sdb2 411648 821247 204800 83 Linux
Command (m for help): n
Partition type:
p primary (2 primary, 0 extended, 2 free)
e extended
Select (default p): e #選擇的分區格式是擴展分區
Partition number (3,4, default 3): 4
First sector (821248-2097151, default 821248):
Using default value 821248
Last sector, +sectors or +size{K,M,G} (821248-2097151, default 2097151):#未輸入分區大小表示將剩下的所有空間分配給該擴展分區
Using default value 2097151
Partition 4 of type Extended and of size 623 MiB is set
Command (m for help): p
Disk /dev/sdb: 1073 MB, 1073741824 bytes, 2097152 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: 0x46480706
Device Boot Start End Blocks Id System
/dev/sdb1 2048 411647 204800 83 Linux
/dev/sdb2 411648 821247 204800 83 Linux
/dev/sdb4 821248 2097151 637952 5 Extended
Command (m for help): n
Partition type:
p primary (2 primary, 1 extended, 1 free)
l logical (numbered from 5)
Select (default p): l
Adding logical partition 5
First sector (823296-2097151, default 823296):
Using default value 823296
Last sector, +sectors or +size{K,M,G} (823296-2097151, default 2097151): +300M
Partition 5 of type Linux and of size 300 MiB is set
Command (m for help): p
Disk /dev/sdb: 1073 MB, 1073741824 bytes, 2097152 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: 0x46480706
Device Boot Start End Blocks Id System
/dev/sdb1 2048 411647 204800 83 Linux
/dev/sdb2 411648 821247 204800 83 Linux
/dev/sdb4 821248 2097151 637952 5 Extended
/dev/sdb5 823296 1437695 307200 83 LinuxCommand (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
[root@Node2 ~]# fdisk -l
Disk /dev/sda: 21.5 GB, 21474836480 bytes, 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 label type: dos
Disk identifier: 0x0008f184
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 1026047 512000 83 Linux
/dev/sda2 1026048 41943039 20458496 8e Linux LVM
Disk /dev/sdb: 1073 MB, 1073741824 bytes, 2097152 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: 0x522f80fa
Device Boot Start End Blocks Id System
/dev/sdb1 2048 411647 204800 83 Linux
/dev/sdb2 411648 821247 204800 83 Linux
/dev/sdb4 821248 2050047 614400 5 Extended
/dev/sdb5 823296 2050047 613376 83 Linux
[root@Node2 ~]# mkfs.ext3 /dev/sdb1 #格式化某個分區
mke2fs 1.42.9 (28-Dec-2013)
Filesystem label=
OS type: Linux
Block size=1024 (log=0) #32位系統的塊大小默認是1k
Fragment size=1024 (log=0)
Stride=0 blocks, Stripe width=0 blocks
51200 inodes, 204800 blocks
10240 blocks (5.00%) reserved for the super user
First data block=1
Maximum filesystem blocks=67371008
25 block groups
8192 blocks per group, 8192 fragments per group
2048 inodes per group
Superblock backups stored on blocks:
8193, 24577, 40961, 57345, 73729
Allocating group tables: done
Writing inode tables: done
Creating journal (4096 blocks): done
Writing superblocks and filesystem accounting information: done[root@Node2 ~]#mkdir /data #創建新目錄用於掛載新的分區
[root@Node2 ~]# mount /dev/sdb1 /data #將/dev/sdb1掛載到/data目錄下
[root@Node2 ~]# vim /etc/fstab
因爲使用mount掛載分區後，系統重啓後分區掛載配置會失效，所以需要修改/etc/fstab配置文件使分區掛載永久生效
3.troubleshooting
學習速度最快的方法是在錯誤中學習。
3.1別人總是說在linux中一塊硬盤最多只能有四個主分區，剩下的都是擴展分區。注意，擴展分區佔用一個主分區位置，即爲如分了三個主分區和一個擴展分區後無法再劃分一個主分區。
3.2擴展分區、主分區、邏輯分區之間的關係：擴展分區大小=邏輯分區之和；硬盤大小=擴展分區+主分區；邏輯分區從擴展分區中劃分。
3.3如果硬是要在有了四個主分區情況下任性地再劃分一個主分區，會怎麼樣呢？試驗爲準。
Command (m for help): P
Disk /dev/sdb: 1073 MB, 1073741824 bytes, 2097152 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: 0x522f80fa
Device Boot Start End Blocks Id System
/dev/sdb1 2048 411647 204800 83 Linux
/dev/sdb2 411648 821247 204800 83 Linux
/dev/sdb3 821248 1230847 204800 83 Linux
/dev/sdb4 1230848 1640447 204800 83 Linux
Command (m for help): n
If you want to create more than four partitions, you must replace a
primary partition with an extended partition first.
#提示已經很明顯，如果想要創建更多的分區，首先得將一個主分區變成一個擴展分區。驗證了linux中一塊磁盤最多隻能劃分四個主分區，如果想劃分更多分區，得至少有一個主分區爲擴展分區，從擴展分區中劃分更多分區。同時也驗證了在linux中一塊磁盤可以沒有擴展分區。總結：主分區最少得有一個，擴展分區最多能有三個。
3.4遇到過一個問題。在進行分區操作中，如果因爲意外因素沒有保存（輸入w）而直接退出了操作命令行，則分區操作不會被保存。
3.5能不能把全部磁盤都變成擴展分區呢？
可以：
Command (m for help): P
Disk /dev/sdb: 1073 MB, 1073741824 bytes, 2097152 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: 0x522f80fa
Device Boot Start End Blocks Id System
/dev/sdb1 2048 411647 204800 5 Extended
3.6不能從擴展分區中劃分主分區，只能劃分爲邏輯分區
Command (m for help): n
Partition type:
p primary (0 primary, 1 extended, 3 free)
l logical (numbered from 5)
Select (default p): l
Adding logical partition 5
First sector (4096-411647, default 4096):
Using default value 4096
Last sector, +sectors or +size{K,M,G} (4096-411647, default 411647): 700+
Value out of range.
#強制劃分會提示 value out of range ，劃分失敗
4.練習
在虛擬機中添加一塊1G的虛擬磁盤，使用fdisk進行分區，分成2個主分區，個擴展分區。
主分區大小分別是200M、200M；
擴展分區大小爲600M；
對於擴展分區，分成兩個邏輯驅動器，分別爲300M。
思路：將物理硬盤掛載到服務器上----->查看新掛載的硬盤並對硬盤進行分區---->分區完成後對新的分區進行格式化--->將分區掛載到某個目錄下----->修改/etc/fstab配置文件