linux动态增加LV空间的方法

一直都说LVM可以在线增加空间，一直都没有试过

下面小试一下：

1.增加硬盘

2.创建PV

3.添加PV到VG

4.扩展LV

1.增加硬盘

该干嘛干嘛

添加后需要重启（有知道不用重启的办法吗）

--这个是新添加的硬盘
[root@localhost ~]# fdisk -l /dev/sdb
Disk /dev/sdb: 5368 MB, 5368709120 bytes
255 heads, 63 sectors/track, 652 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk /dev/sdb doesn't contain a valid partition table

2.创建PV
--命令很简单

--命令很简单
[root@localhost ~]# pvcreate /dev/sdb
Physical volume "/dev/sdb" successfully created

--可以看到新的PV了
[root@localhost ~]# pvdisplay
/dev/hdc: open failed: No medium found
--- Physical volume ---
PV Name /dev/sda2
VG Name VolGroup00
PV Size 9.90 GB / not usable 22.76 MB
Allocatable yes (but full)
PE Size (KByte) 32768
Total PE316
Free PE 0
Allocated PE316
PV UUID n5fS6M-jBiH-n9vU-pBTd-iOCv-BbTe-BUeNZo

"/dev/sdb" is a new physical volume of "5.00 GB"
--- NEW Physical volume ---
PV Name /dev/sdb
VG Name 
PV Size 5.00 GB
Allocatable NO
PE Size (KByte) 0
Total PE0
Free PE 0
Allocated PE0
PV UUID TDs3mN-3ON3-eHbl-cohr-7Hr3-8608-jiLlXG

3.添加PV到VG

--指定对应的VG和PV
[root@localhost ~]# vgextend VolGroup00 /dev/sdb
Volume group "VolGroup00" successfully extended

--看到新的5G添加到VG里面了，状态是没有分配
[root@localhost ~]# vgdisplay 
--- Volume group ---
VG Name VolGroup00
System ID 
Formatlvm2
Metadata Areas2
Metadata Sequence No4
VG Access read/write
VG Status resizable
MAX LV0
Cur LV2
Open LV 2
Max PV0
Cur PV2
Act PV2
VG Size 14.84 GB
PE Size 32.00 MB
Total PE475
Alloc PE / Size 316 / 9.88 GB
FreePE / Size 159 / 4.97 GB
VG UUID x1uyPD-qBgE-2yQV-T1Cb-IGIz-e4LB-fghf1W

4.扩展LV

--先添加2G练手
[root@localhost ~]# lvextend -L +2G /dev/VolGroup00/LogVol00
Extending logical volume LogVol00 to 10.88 GB
Logical volume LogVol00 successfully resized
--成功后还未看到新的空间
[root@localhost ~]# df -m
Filesystem 1M-blocksUsed Available Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
88047362 98889% /
--需要手动刷新
[root@localhost ~]# resize2fs /dev/VolGroup00/LogVol00
resize2fs 1.39 (29-May-2006)
Filesystem at /dev/VolGroup00/LogVol00 is mounted on /; on-line resizing required
Performing an on-line resize of /dev/VolGroup00/LogVol00 to 2850816 (4k) blocks.
The filesystem on /dev/VolGroup00/LogVol00 is now 2850816 blocks long.

--现在就完成了
[root@localhost ~]# df -m
Filesystem 1M-blocksUsed Available Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
 107887365286772% / 

若需要先缩小则使用以下命令：
lvreduce -L -20G /dev/mapper/vg_mysvr-lv_home
resize2fs /dev/mapper/vg_my-lv_home
lvextend -L +20G /dev/mapper/vg_mysvr-lv_root
resize2fs /dev/mapper/vg_mysvr-lv_root