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 pe              316  
  free pe               0  
  allocated pe          316  
  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 pe              0  
  free pe               0  
  allocated pe          0  
  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               
  format                lvm2  
  metadata areas        2  
  metadata sequence no  4  
  vg access             read/write  
  vg status             resizable  
  max lv                0  
  cur lv                2  
  open lv               2  
  max pv                0  
  cur pv                2  
  act pv                2  
  vg size               14.84 gb  
  pe size               32.00 mb  
  total pe              475  
  alloc pe / size       316 / 9.88 gb  
  free  pe / 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-blocks      used available use% mounted on  
/dev/mapper/volgroup00-logvol00  
                          8804      7362       988  89% /  
--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-blocks      used available use% mounted on  
/dev/mapper/volgroup00-logvol00  
                         10788      7365      2867  72% / 

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