RHCE_LAB(6)RHEL5的LVM应用实例（LVM调整大小和删除）

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实验目的：

         理解LVM（逻辑卷管理器），添加、删除和调整LVM大小。

实验环境：

         操作系统：RedHat Enterprise Linux 5 （RHEL5）

         相关软件：lvm2-2.02.16-3.el5

 

实验步骤：

注：在RHCE_LAB(6)中我们建立了3个PV分别是“/dev/hda5 /dev/hda6 /dev/hda7 ”

1. 增大LVM

为VG添加新的PV使其增加容量

[root@linux tmp]#  vgextend vg1 /dev/hda7
  Volume group "vg1" successfully extended

显示VG信息

[root@linux tmp]#  vgdisplay 
  --- Volume group ---
  VG Name               vg1
  System ID             
  Format                lvm2
  Metadata Areas        3
  Metadata Sequence No  8
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                1
  Open LV               1
  Max PV                0
  Cur PV                3
  Act PV                3
  VG Size               252.00 MB
  PE Size               4.00 MB
  Total PE              63
  Alloc PE / Size       45 / 180.00 MB
  Free  PE / Size       18 / 72.00 MB
  VG UUID               GOysUz-Fyeu-ttE0-R3UE-ra3Z-s1dM-l4QZ7n

为LV增加容量

[root@linux tmp]#  lvextend -L +50M /dev/vg1/lv1 
  Rounding up size to full physical extent 52.00 MB
  Extending logical volume lv1 to 252.00 MB
  Logical volume lv1 successfully resized

显示LV信息
[root@linux tmp]#  lvdisplay /dev/vg1/lv1 
  --- Logical volume ---
  LV Name                /dev/vg1/lv1
  VG Name                vg1
  LV UUID                PkCxki-KweE-AcpE-r1KO-cguR-mxUm-xvPP0n
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                252.00 MB
  Current LE             63
  Segments               3
  Allocation             inherit
  Read ahead sectors     0
  Block device           253:3

在线格式化新加的LV，让其可以正常使用

[root@linux tmp]#  resize2fs /dev/vg1/lv1 
resize2fs 1.39 (29-May-2006)
Filesystem at /dev/vg1/lv1 is mounted on /tmp/lvm; on-line resizing required
Performing an on-line resize of /dev/vg1/lv1 to 258048 (1k) blocks.
The filesystem on /dev/vg1/lv1 is now 258048 blocks long.

查看挂载点的信息

[root@linux tmp]#  df -h  /tmp/lvm/
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/vg1-lv1   244M  6.1M  226M   3% /tmp/lvm

2. 减小LV容量

释放LV容量150M

[root@linux tmp]#  reduce -L -150M /dev/vg1/lv1 
  Rounding up size to full physical extent 148.00 MB
  WARNING: Reducing active and open logical volume to 104.00 MB
  THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce lv1? [y/n]: y
  Reducing logical volume lv1 to 104.00 MB
  Logical volume lv1 successfully resized

查看LV信息

[root@linux tmp]#  lvdisplay /dev/vg1/lv1 
  --- Logical volume ---
  LV Name                /dev/vg1/lv1
  VG Name                vg1
  LV UUID                PkCxki-KweE-AcpE-r1KO-cguR-mxUm-xvPP0n
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                104.00 MB
  Current LE             26
  Segments               2
  Allocation             inherit
  Read ahead sectors     0
  Block device           253:3

删除VG中的容量100M的分区“/dev/hda6”

[root@linux tmp]#  vgreduce vg1 /dev/hda6
  Removed "/dev/hda6" from volume group "vg1"

显示VG信息

[root@linux tmp]#  vgdisplay vg1
  --- Volume group ---
  VG Name               vg1
  System ID             
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  17
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                1
  Open LV               1
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               152.00 MB
  PE Size               4.00 MB
  Total PE              38
  Alloc PE / Size       24 / 96.00 MB
  Free  PE / Size       14 / 56.00 MB
  VG UUID               GOysUz-Fyeu-ttE0-R3UE-ra3Z-s1dM-l4QZ7n

删除PV“/dev/hda6”

[root@linux tmp]#  pvremove /dev/hda6
  Labels on physical volume "/dev/hda6" successfully wiped

显示PV信息
[root@linux tmp]#  pvdisplay 
  --- Physical volume ---
  PV Name               /dev/hda5
  VG Name               vg1
  PV Size               101.94 MB / not usable 1.94 MB
  Allocatable           yes 
  PE Size (KByte)       4096
  Total PE              25
  Free PE               1
  Allocated PE          24
  PV UUID               jSaI8a-D2B3-5HSA-LkPT-hQ1v-gut6-yY10t6
   
  --- Physical volume ---
  PV Name               /dev/hda7
  VG Name               vg1
  PV Size               54.88 MB / not usable 2.88 MB
  Allocatable           yes 
  PE Size (KByte)       4096
  Total PE              13
  Free PE               13
  Allocated PE          0
  PV UUID               KLBWkX-l694-Yagy-BdHf-RkJ2-2NIC-ltGty0

3. 删除所有的LVM

取消挂载的分区

[root@linux tmp]#  umount /tmp/lvm/

删除LV

[root@linux tmp]#  lvremove /dev/vg1/lv1 
Do you really want to remove active logical volume "lv1"? [y/n]:  y
  Logical volume "lv1" successfully removed

删除VG
[root@linux tmp]#  vgremove vg1
  Volume group "vg1" successfully removed

删除PV
[root@linux tmp]# pvremove /dev/hda5 /dev/hda7
  Labels on physical volume "/dev/hda5" successfully wiped
  Labels on physical volume "/dev/hda7" successfully wiped

删除物理分区的方法是使用“fdisk”命令

[root@linux tmp]#  fdisk /dev/hda

纤细信息显示如下

Command (m for help):  d
Partition number (1-7):  7

Command (m for help):  d
Partition number (1-6):  6

Command (m for help):  d
Partition number (1-5):  5

Command (m for help):  p

Disk /dev/hda: 80.0 GB, 80026361856 bytes
255 heads, 63 sectors/track, 9729 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/hda1   *           1          16      128488+  83  Linux
/dev/hda2              17        7665    61440592+  8e  Linux LVM
/dev/hda3            7666        7796     1052257+  82  Linux swap / Solaris
/dev/hda4            7797        9729    15526822+   5  Extended

Command (m for help):

 

实验总结：

         LVM的建立和删除，增加容量和容量减小是一个互逆的过程。

 

RHCE_LAB(6)RHEL5的LVM应用实例（LVM调整大小和删除）——结束