參考文檔： Linux命令大全
需求：測試環境虛擬機某個目錄下空間不足，準備通過添加一塊磁盤，並將該目錄掛載到該磁盤
前面幾步在測試服務器上操作的，截圖困難，所以網上找了幾張設置圖
- 關閉虛擬機（沒測試過不關閉的情況）
- 虛擬機中添加一塊新的磁盤
![虛擬機中添加一塊新的磁盤.png]()
- 選擇磁盤類型
![選擇磁盤類型.png]()
- 創建新磁盤
- 設置大小、拆分方式
![設置大小、拆分方式.png]()
- 設定文件名（一般默認即可）
![設定文件名.png]()
- 確定（一定要確定，不然不會保存的）
![確定.png]()
- 重啓虛擬機
- fdisk觀察硬盤實體使用情況
[root@node3 ~]# fdisk -l
Disk /dev/sda: 536.9 GB, 536870912000 bytes, 1048576000 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: 0x000bd826
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 2099199 1048576 83 Linux
/dev/sda2 2099200 1048575999 523238400 8e Linux LVM
//新加的磁盤（100G）
Disk /dev/sdb: 107.4 GB, 107374182400 bytes, 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 /dev/mapper/centos-root: 53.7 GB, 53687091200 bytes, 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 /dev/mapper/centos-swap: 2147 MB, 2147483648 bytes, 4194304 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 /dev/mapper/centos-home: 480.0 GB, 479954206720 bytes, 937410560 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- 選擇要進行操作的磁盤
[root@node3 ~]# fdisk /dev/sdb
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 0x2890866a.- 輸入m列出可以執行的命令：
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 //刪除現有分區
l list known partition types
m print this menu
n add a new partition //添加新的分區
o create a new empty DOS partition table
p print the partition table //查看分區情況
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)- 輸入p列出磁盤目前的分區情況 （如果是新的磁盤 忽略步驟）
Command (m for help): p
Disk /dev/sdb: 3221 MB, 3221225472 bytes
255 heads, 63 sectors/track, 391 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 1 8001 8e Linux LVM
/dev/sdb2 2 26 200812+ 83 Linux- 刪除現有分區
Command (m for help): d
Partition number (1-4): 1
Command (m for help): d
Selected partition 2- 確認分區已經刪除
Command (m for help): p
Disk /dev/sdb: 3221 MB, 3221225472 bytes
255 heads, 63 sectors/track, 391 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
Command (m for help):- 建立新的磁盤分區（兩個主磁盤分區）
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p //建立主分區
Partition number (1-4): 1 //分區號
First cylinder (1-391, default 1): //分區起始位置
Using default value 1
last cylinder or +size or +sizeM or +sizeK (1-391, default 391): 100 //分區結束位置，單位爲扇區(磁盤扇區默認是512Byte)
Command (m for help): n //再建立一個分區
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 2 //分區號爲2
First cylinder (101-391, default 101):
Using default value 101
Last cylinder or +size or +sizeM or +sizeK (101-391, default 391): +200M //分區結束位置，單位爲M- 建一個擴展分區
Command (m for help): n
Command action
e extended
p primary partition (1-4)
e //選擇擴展分區
Partition number (1-4): 3
First cylinder (126-391, default 126):
Using default value 126
Last cylinder or +size or +sizeM or +sizeK (126-391, default 391)://剩下的空間都用做擴展分區
Using default value 391- 查看擴展分區
Command (m for help): p
Disk /dev/sdb: 3221 MB, 3221225472 bytes
255 heads, 63 sectors/track, 391 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 100 803218+ 83 Linux
/dev/sdb2 101 125 200812+ 83 Linux
/dev/sdb3 126 391 2136645 5 Extended- 擴展分區上建立邏輯分區
Command (m for help): n
Command action
l logical (5 or over)
p primary partition (1-4)
l //選擇邏輯分區
First cylinder (126-391, default 126):
Using default value 126
Last cylinder or +size or +sizeM or +sizeK (126-391, default 391): +400M
Command (m for help): n
Command action
l logical (5 or over)
p primary partition (1-4)
l
First cylinder (176-391, default 176):
Using default value 176
Last cylinder or +size or +sizeM or +sizeK (176-391, default 391):
Using default value 391- 查看當前分區情況
Command (m for help): p
Disk /dev/sdb: 3221 MB, 3221225472 bytes
255 heads, 63 sectors/track, 391 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 100 803218+ 83 Linux
/dev/sdb2 101 125 200812+ 83 Linux
/dev/sdb3 126 391 2136645 5 Extended
/dev/sdb5 126 175 401593+ 83 Linux
/dev/sdb6 176 391 1734988+ 83 Linux
Command (m for help):從上面的結果我們可以看到，在硬盤sdb我們建立了2個主分區（sdb1，sdb2），1個擴展分區（sdb3），2個邏輯分區（sdb5，sdb6）
注意：主分區和擴展分區的磁盤號位1-4，也就是說最多有4個主分區或者擴展分區，邏輯分區開始的磁盤號爲5，因此在這個實驗中試沒有sdb4的。
- 保存分區操作
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
分區創建方式按照參考文檔的操作，但是我並沒有創建這麼多分區，100G全部創建了主分區即
/dev/sdb1
- fdisk 查看硬盤分區情況
[root@node3 ~]# fdisk -l
Disk /dev/sda: 536.9 GB, 536870912000 bytes, 1048576000 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: 0x000bd826
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 2099199 1048576 83 Linux
/dev/sda2 2099200 1048575999 523238400 8e Linux LVM
Disk /dev/sdb: 107.4 GB, 107374182400 bytes, 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 label type: dos
Disk identifier: 0x2890866a
Device Boot Start End Blocks Id System
/dev/sdb1 2048 209715199 104856576 83 Linux //新的分區（sbd1:100G）
Disk /dev/mapper/centos-root: 53.7 GB, 53687091200 bytes, 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 /dev/mapper/centos-swap: 2147 MB, 2147483648 bytes, 4194304 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 /dev/mapper/centos-home: 480.0 GB, 479954206720 bytes, 937410560 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- cat /proc/partitions 查看磁盤文件信息
[root@node3 ~]# cat /proc/partitions
major minor #blocks name
8 0 524288000 sda
8 1 1048576 sda1
8 2 523238400 sda2
8 16 104857600 sdb
8 17 104856576 sdb1
11 0 1048575 sr0
253 0 52428800 dm-0
253 1 2097152 dm-1
253 2 468705280 dm-2- mkfs -t ext3 /dev/sdb1格式化分區
[root@node3 ~]# mkfs -t ext3 /dev/sdb1
mke2fs 1.42.9 (28-Dec-2013)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
6553600 inodes, 26214144 blocks
1310707 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4294967296
800 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000, 7962624, 11239424, 20480000, 23887872
Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done- mount /dev/sdb1 /guazai
#/usr/hdp/ 目錄要先存在
[root@node3 ~]# mount /dev/sdb1 /usr/hdp/- 查看掛載情況
[root@node3 usr]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/centos-root 50G 50G 20K 100% /
devtmpfs 3.8G 0 3.8G 0% /dev
tmpfs 3.9G 0 3.9G 0% /dev/shm
tmpfs 3.9G 12M 3.8G 1% /run
tmpfs 3.9G 0 3.9G 0% /sys/fs/cgroup
/dev/sda1 1014M 142M 873M 14% /boot
/dev/mapper/centos-home 447G 1018M 446G 1% /home
tmpfs 781M 0 781M 0% /run/user/0
/dev/sdb1 99G 60M 94G 1% /usr/hdp //掛載成功- 取消掛載
[root@node3 /]# umount /dev/sdb1
[root@node3 /]# df -k
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/mapper/centos-root 52403200 52403180 20 100% /
devtmpfs 3983896 0 3983896 0% /dev
tmpfs 3996168 0 3996168 0% /dev/shm
tmpfs 3996168 11992 3984176 1% /run
tmpfs 3996168 0 3996168 0% /sys/fs/cgroup
/dev/sda1 1038336 145260 893076 14% /boot
/dev/mapper/centos-home 468476420 1041428 467434992 1% /home
tmpfs 799236 0 799236 0% /run/user/0取消掛載成功
還可以用umount /usr/hdp取消掛載