LVM逻辑卷管理---用来扩展分区内存

[root@lvm ~]#
[root@lvm ~]# pvcreate /dev/sd[de]
  Physical volume "/dev/sdd" successfully created
  Physical volume "/dev/sde" successfully created
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[root@lvm ~]# pvcreate /dev/sdf 创建pv
  Physical volume "/dev/sdf" successfully created
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[root@lvm ~]# pvdisplay /dev/sde 显示下pv的详细信息
  "/dev/sde" is a new physical volume of "20.00 GB"
  --- NEW Physical volume ---
  PV Name               /dev/sde
  VG Name              
  PV Size               20.00 GB
  Allocatable           NO
  PE Size (KByte)       0
  Total PE              0
  Free PE               0
  Allocated PE          0
  PV UUID               R4WGy1-ui4I-gsrB-EkFu-grfi-w4hN-VCkj3n
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[root@lvm ~]# pvscan   扫描下pv
  PV /dev/sdd                      lvm2 [12.00 GB]
  PV /dev/sde                      lvm2 [20.00 GB]
  PV /dev/sdf                      lvm2 [20.00 GB]
  Total: 3 [52.00 GB] / in use: 0 [0   ] / in no VG: 3 [52.00 GB]
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vgcreate photo /dev/sd[def]  创建vg
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[root@lvm ~]# vgscan  扫描vg
  Reading all physical volumes.  This may take a while...
  Found volume group "photo" using metadata type lvm2
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[root@lvm ~]# vgdisplay  显示vg的信息
  --- Volume group ---
  VG Name               photo
  System ID            
  Format                lvm2
  Metadata Areas        3
  Metadata Sequence No  1
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                0
  Open LV               0
  Max PV                0
  Cur PV                3
  Act PV                3
  VG Size               51.99 GB
  PE Size               4.00 MB
  Total PE              13309
  Alloc PE / Size       0 / 0  
  Free  PE / Size       13309 / 51.99 GB
  VG UUID               PLphxo-OP8v-ZSwy-Lw6C-0tqD-EvsJ-RdJ2FZ
   ================

[root@lvm ~]# pvscan
  PV /dev/sdd   VG photo   lvm2 [12.00 GB / 12.00 GB free]
  PV /dev/sde   VG photo   lvm2 [20.00 GB / 20.00 GB free]
  PV /dev/sdf   VG photo   lvm2 [20.00 GB / 20.00 GB free]
  Total: 3 [51.99 GB] / in use: 3 [51.99 GB] / in no VG: 0 [0   ]
可以查询哪个pv属于哪个vg
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[root@lvm ~]# lvcreate -L 20G -n 7yue5 photo
  /dev/cdrom: open failed: 只读文件系统
  Logical volume "7yue5" created
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-L  指定大小
-n  指定lv的名字
7yue5 是lv的名字
photo是vg的名字
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[root@lvm ~]# lvcreate -L 25G -n 9yue5 photo
  /dev/cdrom: open failed: 只读文件系统
  Logical volume "9yue5" created
[root@lvm ~]# lvscan
  ACTIVE            '/dev/photo/7yue5' [20.00 GB] inherit
  ACTIVE            '/dev/photo/9yue5' [25.00 GB] inherit
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[root@lvm ~]# mkfs.ext3 /dev/photo/7yue5
[root@lvm ~]# mkfs.ext3 /dev/photo/9yue5
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修改/etc/fstab文件
添加
/dev/photo/7yue5         /7yue5     ext3    defaults  0 0
/dev/photo/9yue5         /9yue5     ext3    defaults  0 0
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实现开机自动挂载
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[root@lvm ~]# mkdir /7yue5
[root@lvm ~]# mkdir /9yue5
新建挂载点
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mount -a
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扩容vg
 1.[root@lvm ~]# pvcreate /dev/sdg
  Physical volume "/dev/sdg" successfully created
[root@lvm ~]# pvcreate /dev/sdh
  Physical volume "/dev/sdh" successfully created
 2.[root@lvm ~]# vgextend photo /dev/sd[gh]
  /dev/cdrom: open failed: 只读文件系统

  /dev/cdrom: open failed: 只读文件系统
  Attempt to close device '/dev/cdrom' which is not open.
  Volume group "photo" successfully extended
给photo 这个vg扩容，增加了2个pv进来
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扩容lv
 1.[root@lvm 7yue5]# lvextend -L +20G /dev/photo/7yue5
扩容20G
  /dev/cdrom: open failed: 只读文件系统
  Extending logical volume 7yue5 to 40.00 GB
 2.[root@lvm 7yue5]# resize2fs /dev/photo/7yue5 重新识别文件系统的大小
resize2fs 1.39 (29-May-2006)
Filesystem at /dev/photo/7yue5 is mounted on /7yue5; on-line resizing required
Performing an on-line resize of /dev/photo/7yue5 to 10485760 (4k) blocks.
The filesystem on /dev/photo/7yue5 is now 10485760 blocks long.
 3.df -Th   查看是否生效
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