centos7扩展磁盘空间

[root@hn ~]# fdisk /dev/sdb

The device presents a logical sector size that is smaller than
the physical sector size. Aligning to a physical sector (or optimal
I/O) size boundary is recommended, or performance may be impacted.
欢迎使用 fdisk (util-linux 2.23.2)。

更改将停留在内存中，直到您决定将更改写入磁盘。
使用写入命令前请三思。

命令(输入 m 获取帮助)：n
Partition type:
p primary (1 primary, 0 extended, 3 free)
e extended
Select (default p): p
分区号 (2-4，默认 2)：
起始 扇区 (476773168-976773167，默认为 476774400)：
将使用默认值 476774400
Last 扇区, +扇区 or +size{K,M,G} (476774400-976773167，默认为 976773167)：
将使用默认值 976773167
分区 2 已设置为 Linux 类型，大小设为 238.4 GiB

命令(输入 m 获取帮助)：w
The partition table has been altered!

Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error 16: 设备或资源忙.
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)
正在同步磁盘。
[root@hn ~]# ll /dev/sd
sda sda1 sda2 sda3 sdb sdb1
[root@hn ~]# ll /dev/sdb
sdb sdb1
[root@hn ~]# ll /dev/sdb
sdb sdb1
[root@hn ~]# partprobe

[root@hn ~]# mkfs.xfs /dev/sdb1
mkfs.xfs: /dev/sdb1 appears to contain an existing filesystem (LVM2_member).
mkfs.xfs: Use the -f option to force overwrite.

[root@hn ~]# mkfs.xfs -f /dev/sdb1
meta-data=/dev/sdb1 isize=256 agcount=4, agsize=14899098 blks
= sectsz=4096 attr=2, projid32bit=1
= crc=0 finobt=0
data = bsize=4096 blocks=59596390, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=0
log =internal log bsize=4096 blocks=29099, version=2
= sectsz=4096 sunit=1 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0