/dev/sdb1을 확장하고 싶습니다

[root@localhost ~]# df -h ; fdisk -l 
Filesystem               Size  Used Avail Use% Mounted on
devtmpfs                 894M     0  894M   0% /dev
tmpfs                    910M     0  910M   0% /dev/shm
tmpfs                    910M   11M  900M   2% /run
tmpfs                    910M     0  910M   0% /sys/fs/cgroup
/dev/mapper/centos-root   13G   12G  997M  93% /
tmpfs                    712M   20K  712M   1% /tmp
/dev/sda1               1014M  249M  766M  25% /boot
tmpfs                    182M   36K  182M   1% /run/user/0
/dev/sr0                 9.6G  9.6G     0 100% /run/media/root/CentOS 7 x86_64

Disk /dev/sda: 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: 0x000c26ad
   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048     2099199     1048576   83  Linux
/dev/sda2         2099200    31457279    14679040   8e  Linux LVM

Disk /dev/sdb: 75.2 GB, 75161927680 bytes, 146800640 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: 0xbe878527

  Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048   104857599    52427776   83  Linux

Disk /dev/mapper/centos-root: 13.4 GB, 13417578496 bytes, 26206208 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: 1610 MB, 1610612736 bytes, 3145728 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