1、查看磁盘情况：

   [root@xus ~]# df -h
Filesystem      Size  Used Avail Use% Mounted on
devtmpfs        7.8G     0  7.8G   0% /dev
tmpfs           7.9G     0  7.9G   0% /dev/shm
tmpfs           7.9G   17M  7.8G   1% /run
tmpfs           7.9G     0  7.9G   0% /sys/fs/cgroup
/dev/vda1        20G  2.4G   18G  12% /
/dev/vdb1        69G   24K   66G   1% /dataext
tmpfs           1.6G     0  1.6G   0% /run/user/0

2、查看磁盘挂载

[root@xus ~]# fdisk -l
# /dev/vda已经做了分区 
Disk /dev/vda: 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: 0x0000c4ba

Device Boot      Start         End        Blo