出现这个错误是在我试图将扩容的LV应用到文件系统上的时候爆出的，具体的情况如下所示：

[root@oel71 ~]# df -h
Filesystem           Size  Used Avail Use% Mounted on
/dev/mapper/ol-root   18G   11G  6.7G  62% /
devtmpfs             1.8G     0  1.8G   0% /dev
tmpfs                1.8G   80K  1.8G   1% /dev/shm
tmpfs                1.8G  8.9M  1.8G   1% /run
tmpfs                1.8G     0  1.8G   0% /sys/fs/cgroup
/dev/sda1            497M  150M  348M  31% /boot
[root@oel71 ~]# 
[root@oel71 ~]# lvdisplay 
  --- Logical volume ---
  LV Path                /dev/ol/swap
  LV Name                swap
  VG Name                ol
  LV UUID                AbAcmW-6Ar7-N0IY-DTwv-VfUf-nGuc-dhlDcw
  LV Write Access        read/write
  LV Creation host, time localhost, 2015-12-04 06:20:48 +0800
  LV Status              available
  # open                 2
  LV Size                2.00 GiB
  Current LE             512
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           252:1
   
  --- Logical volume ---
  LV Path                /dev/ol/root
  LV Name                root
  VG Name                ol
  LV UUID                GY9Oto-5SR7-GrbL-Ml6i-8Cwu-sy79-Cfz01X
  LV Write Access        read/write
  LV Creation host, time localhost, 2015-12-04 06:20:49 +0800
  LV Status              available
  # open                 1
  LV Size                57.47 GiB
  Current LE             14712
  Segments               2
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           252:0
   
[root@oel71 ~]# 
[root@oel71 ~]# resize2fs /dev/mapper/ol-root 
resize2fs 1.42.9 (28-Dec-2013)
resize2fs: Bad magic number in super-block while trying to open /dev/mapper/ol-root
Couldn't find valid filesystem superblock.
[root@oel71 ~]#

解法：

[root@oel71 ~]# xfs_growfs /dev/mapper/ol-root 
meta-data=/dev/mapper/ol-root    isize=256    agcount=4, agsize=1144832 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=0        finobt=0
data     =                       bsize=4096   blocks=4579328, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=0
log      =internal               bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
data blocks changed from 4579328 to 15065088
[root@oel71 ~]# 
[root@oel71 ~]# df -h
Filesystem           Size  Used Avail Use% Mounted on
/dev/mapper/ol-root   58G   11G   47G  19% /
devtmpfs             1.8G     0  1.8G   0% /dev
tmpfs                1.8G   80K  1.8G   1% /dev/shm
tmpfs                1.8G  8.9M  1.8G   1% /run
tmpfs                1.8G     0  1.8G   0% /sys/fs/cgroup
/dev/sda1            497M  150M  348M  31% /boot
[root@oel71 ~]#

————————————————————————
Done。