以下命令针对不增加LUN，只在存储端修改LUN的大小后，linux在线更新LUN信息，并扩容LVM
multipath -ll /dev/mapper/dev01_OLD
for i in $(ls /sys/class/scsi_device/); do echo 1> /sys/class/scsi_device/$i/device/rescan; done #扫描所有LUN
multipathd resize map /dev/mapper/dev01_OLD
#扩容lvm
pvresize /dev/mapper/dev01_OLD
lvextend /dev/mapper/vgnfs-lvnfs -l +100%FREE
resize2fs /dev/mapper/vgnfs-lvnfs