--1.打开调试：
[root@db01 storage]# set -x
--2.执行命令：
[root@db01 storage]# /usr/sbin/lvextend -r -L 710M /dev/shazam/storage
+ /usr/sbin/lvextend -r -L 710M /dev/shazam/storage
Rounding size to boundary between physical extents: 712.00 MiB.
Size of logical volume shazam/storage changed from 700.00 MiB (175 extents) to 712.00 MiB (178 extents).
Logical volume shazam/storage successfully resized.
resize2fs 1.42.9 (28-Dec-2013)
Filesystem at /dev/mapper/shazam-storage is mounted on /storage; on-line resizing required
old_desc_blocks = 6, new_desc_blocks = 6
The filesystem on /dev/mapper/shazam-storage is now 729088 blocks long.
++ __vte_prompt_command
+++ HISTTIMEFORMAT=
+++ history 1
+++ sed 's/^ *[0-9]\+ *//'
++ local 'command=/usr/sbin/lvextend -r -L 710M /dev/shazam/storage '
++ command='/usr/sbin/lvextend -r -L 710M /dev/shazam/storage '
++ local 'pwd=~'
++ '[' /storage '!=' /root ']'
++ pwd=/storage
+++ __vte_osc7
++++ __vte_urlencode /storage
++++ LC_ALL=C
++++ str=/storage
++++ '[' -n /storage ']'
++++ safe=/storage
++++ printf %s /storage
++++ str=
++++ '[' -n '' ']'
++++ '[' -n '' ']'
+++ printf '\033]7;file://%s%s\007' db01 /storage
++ printf '\033]777;notify;Command completed;%s\007\033]0;%s@%s:%s\007%s' '/usr/sbin/lvextend -r -L 710M /dev/shazam/storage ' root db01 /storage ''
--通过以上命令可以看到，在加了 -r 选项后，自动调用了 resize2fs
--3.关闭 调试信息
[root@db01 storage]# set -x
之后就没有信息调试信息了。