环境，天翼云弹性主机centos7.3 系统盘40G 。扩展盘100G 系统默认未挂载到系统里
[root@mail ~]# df -h //查看系统磁盘使用情况，这里是看不到未挂载的硬盘的
Filesystem Size Used Avail Use% Mounted on
/dev/xvda2 36G 5.7G 28G 17% /
devtmpfs 902M 0 902M 0% /dev
tmpfs 908M 4.0K 908M 1% /dev/shm
tmpfs 908M 8.5M 900M 1% /run
tmpfs 908M 0 908M 0% /sys/fs/cgroup
tmpfs 182M 0 182M 0% /run/user/0
tmpfs 182M 0 182M 0% /run/user/9008
root@mail ~]# fdisk -l //使用 fdisk -l 可以看到100G的硬盘 和路径 /dev/xvde
Disk /dev/xvda: 42.9 GB, 42949672960 bytes, 83886080 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: 0x000a9cf3
Device Boot Start End Blocks Id System
/dev/xvda1 2048 8390655 4194304 82 Linux swap / Solaris
/dev/xvda2 * 8390656 83886079 37747712 83 Linux
Disk /dev/xvde: 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: 0x0e5de398
Device Boot Start End Blocks Id System
[root@mail ~]# fdisk /dev/xvde //使用 fdisk 进行分区
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.
Command (m for help): n //选n 新建 然后选e（扩展分区） 一路回车默认
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p): e
Partition number (1-4, default 1):
First sector (2048-209715199, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-209715199, default 209715199):
Using default value 209715199
Partition 1 of type Extended and of size 100 GiB is set
Command (m for help): b^Hn^H^H
There is no *BSD partition on (null).
Command (m for help): n //继续n新建 然后 L （新建逻辑分区）一路 回车默认设置
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 (4096-209715199, default 4096):
Using default value 4096
Last sector, +sectors or +size{K,M,G} (4096-209715199, default 209715199):
Using default value 209715199
Partition 5 of type Linux and of size 100 GiB is set
Command (m for help): w //保存退出
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@mail ~]# fdisk /dev/xvde //在继续 进去新磁盘
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.
Command (m for help): p // p 可以查看新磁盘的分区情况
Disk /dev/xvde: 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: 0x0e5de398
Device Boot Start End Blocks Id System
/dev/xvde1 2048 209715199 104856576 5 Extended
/dev/xvde5 4096 209715199 104855552 83 Linux
Command (m for help): quit //退出设置
接下来格式化磁盘
[root@2018sh001 ~]# mkfs.xfs /dev/vdb5 //这里注意 格式只能对逻辑分区进行操作，无法对扩展分区进行操作，第一次弄的时候吃了不少药
meta-data=/dev/vdb5 isize=256 agcount=4, agsize=6553472 blks
= sectsz=512 attr=2, projid32bit=1
= crc=0 finobt=0, sparse=0
data = bsize=4096 blocks=26213888, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=0
log =internal log bsize=4096 blocks=12799, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
[root@2018sh001 /]# mkdir -p mail //根目录下新建一个文件夹 未接下里的挂载做准备
[root@2018sh001 /]# mount /dev/vdb5 /mail //把之前格式化好的磁盘和新建的文件夹挂载关联
[root@2018sh001 /]# df -i //查看挂载成功
Filesystem Inodes IUsed IFree IUse% Mounted on
devtmpfs 218424 345 218079 1% /dev
tmpfs 222907 2 222905 1% /dev/shm
tmpfs 222907 450 222457 1% /run
tmpfs 222907 15 222892 1% /sys/fs/cgroup
/dev/vda2 37747712 79269 37668443 1% /
tmpfs 222907 1 222906 1% /run/user/9008
tmpfs 222907 1 222906 1% /run/user/0
/dev/vdb5 104855552 3 104855549 1% /mail // 挂载成功
[root@2018sh001 /]# ls -l /dev/disk/by-uuid/ //查看磁盘的UUID
total 0
lrwxrwxrwx 1 root root 10 Feb 11 16:46 3b4db05b-cb08-4cd2-84a5-89f41b392401 -> ../../vda2
lrwxrwxrwx 1 root root 10 Feb 13 15:46 611cb800-74d2-42fb-880b-f95ec82521d1 -> ../../vdb5 // 记录好该条UUID记录
lrwxrwxrwx 1 root root 10 Feb 11 16:46 a2aacb12-aefc-44b6-8a38-4de5e86462b9 -> ../../vda1
vim /etc/fstab // 编辑磁盘启动文件
UUID=3b4db05b-cb08-4cd2-84a5-89f41b392401 / xfs defaults 0 0
UUID=a2aacb12-aefc-44b6-8a38-4de5e86462b9 swap swap defaults 0 0
UUID=611cb800-74d2-42fb-880b-f95ec82521d1 /mail xfs defaults 0 0 //添加这条记录 :wq保存
reboot 重启
[root@2018sh001 ~]# df -h //查看磁盘使用情况
Filesystem Size Used Avail Use% Mounted on
devtmpfs 854M 0 854M 0% /dev
tmpfs 871M 0 871M 0% /dev/shm
tmpfs 871M 8.4M 863M 1% /run
tmpfs 871M 0 871M 0% /sys/fs/cgroup
/dev/vda2 36G 5.1G 31G 14% /
/dev/vdb5 100G 33M 100G 1% /mail // 挂载信息重启后还在
tmpfs 175M 0 175M 0% /run/user/0