因生产需要对/data目录进行扩容，由原来的90G扩容到190G，增加100G的空间.
生产环境是RHEL服务器，后端通过光纤交换机连的EMC存储。首先在EMC存储上把空闲的硬盘做RAID，划分LUN，映射到生产RHEL服务器。
（注意：此种扩容的前提是分区必须采用LVM格式完成）
一、原服务器磁盘信息
#df -H
/dev/datavg/lv_data
90G 81G 9G 90% /data
#lvdisplay
--- Logical volume ---
LV Name /dev/datavg/lv_data
VG Name datavg
LV UUID Sgpcu1-7Xhr-0gwH-qjJ6-QwBB-k2KA-9DJvFt
LV Write Access read/write
LV Status available
# open 1
LV Size 90.00 GB
Current LE 24882
Segments 10
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:1
二、重启服务器，识别到EMC上新加的LUN后，在服务器端进行扩容datavg卷
#powerrmt display dev=all
Pseudo name=emcpowery
CLARiiON ID=CKM00110900942 [SG_DRAGON]
Logical device ID=6006016003602C00F0154D04917BE011 [LUN 211]
state=alive; policy=CLAROpt; priority=0; queued-IOs=0;
Owner: default=SP A, current=SP A Array failover mode: 1
==============================================================================
--------------- Host --------------- - Stor - -- I/O Path -- -- Stats ---
### HW Path I/O Paths Interf. Mode State Q-IOs Errors
==============================================================================
7 qla2xxx sdan SP B0 active alive 0 0
5 qla2xxx sdas SP B1 active alive 0 0
7 qla2xxx sdbo SP A1 active alive 0 0
5 qla2xxx sdq SP A0 active alive 0 0
