lvm逻辑卷管理实验（创建、扩容、删除LVM）

一、新建LVM

1、查看磁盘的分区状态
[root@rhel5 ~]# fdisk -l

Disk /dev/sda: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1         765     6144831   83  Linux
/dev/sda2             766        1785     8193150   83  Linux
/dev/sda3            1786        2046     2096482+  82  Linux swap / Solaris
/dev/sda4            2047        2610     4530330    5  Extended
/dev/sda5            2047        2301     2048256   83  Linux
/dev/sda6            2302        2428     1020096   83  Linux

Disk /dev/sdb: 2147 MB, 2147483648 bytes
255 heads, 63 sectors/track, 261 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1          13      104391   83  Linux
/dev/sdb2              14          26      104422+  83  Linux
/dev/sdb3              27          39      104422+  83  Linux
/dev/sdb4              40         162      987997+   5  Extended
2、建立物理卷

[root@rhel5 ~]# pvcreate /dev/sdb1 /dev/sdb2 /dev/sdb3
  Physical volume "/dev/sdb1" successfully created
  Physical volume "/dev/sdb2" successfully created
  Physical volume "/dev/sdb3" successfully created

3、建立名为vgwuhan的卷组并进行查看
[root@rhel5 ~]# vgcreate vgwuhan /dev/sdb1 /dev/sdb2 /dev/sdb3
  /dev/cdrom: open failed: Read-only file system
  /dev/cdrom: open failed: Read-only file system
  Attempt to close device '/dev/cdrom' which is not open.
  /dev/cdrom: open failed: Read-only file system
  Attempt to close device '/dev/cdrom' which is not open.
  /dev/cdrom: open failed: Read-only file system
  Attempt to close device '/dev/cdrom' which is not open.
  Volume group "vgwuhan" successfully created
[root@rhel5 ~]# vgdisplay
  --- Volume group ---
  VG Name               vgwuhan
  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               300.00 MB
  PE Size               4.00 MB
  Total PE              75
  Alloc PE / Size       0 / 0  
  Free  PE / Size       75 / 300.00 MB
  VG UUID               MhEO9N-p5p8-SEbm-Dsr9-8WFq-6O33-7U6JNB

4、创建逻辑卷（文件名为lvmwuhan，大小为100M)
[root@rhel5 ~]# lvcreate -L 100M -n lvmwuhan vgwuhan
  /dev/cdrom: open failed: Read-only file system
  Logical volume "lvmwuhan" created
[root@rhel5 ~]# lvdisplay -v
    Finding all logical volumes
  --- Logical volume ---
  LV Name                /dev/vgwuhan/lvmwuhan
  VG Name                vgwuhan
  LV UUID                E6H3PK-enYT-n1wm-VSax-WIo7-VyiN-1LI5jm
  LV Write Access        read/write
  LV Status              available
  # open                 0
  LV Size                100.00 MB
  Current LE             25
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:0
5、格式化逻辑卷
[root@rhel5 ~]# mkfs.ext3 /dev/vgwuhan/lvmwuhan
mke2fs 1.39 (29-May-2006)
Filesystem label=
OS type: Linux
Block size=1024 (log=0)
Fragment size=1024 (log=0)
25688 inodes, 102400 blocks
5120 blocks (5.00%) reserved for the super user
First data block=1
Maximum filesystem blocks=67371008
13 block groups
8192 blocks per group, 8192 fragments per group
1976 inodes per group
Superblock backups stored on blocks:
        8193, 24577, 40961, 57345, 73729

Writing inode tables: done                           
Creating journal (4096 blocks): done
Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 25 mounts or
180 days, whichever comes first.  Use tune2fs -c or -i to override.

6、挂载逻辑卷
[root@rhel5 ~]# mount /dev/vgwuhan/lvmwuhan /mnt
[root@rhel5 ~]# cd /mnt

7、在线扩容
[root@rhel5 ~]# lvextend -L +100M /dev/vgwuhan/lvmwuhan
  /dev/cdrom: open failed: Read-only file system
  Extending logical volume lvmwuhan to 200.00 MB
  Logical volume lvmwuhan successfully resized
[root@rhel5 ~]# lvdisplay
  --- Logical volume ---
  LV Name                /dev/vgwuhan/lvmwuhan
  VG Name                vgwuhan
  LV UUID                E6H3PK-enYT-n1wm-VSax-WIo7-VyiN-1LI5jm
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                200.00 MB
  Current LE             50
  Segments               2
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:0
  
[root@rhel5 ~]# resize2fs -p /dev/vgwuhan/lvmwuhan
resize2fs 1.39 (29-May-2006)
Filesystem at /dev/vgwuhan/lvmwuhan is mounted on /mnt; on-line resizing required
Performing an on-line resize of /dev/vgwuhan/lvmwuhan to 204800 (1k) blocks.
The filesystem on /dev/vgwuhan/lvmwuhan is now 204800 blocks long.

[root@rhel5 ~]# lv
lv           lvdisplay    lvmdiskscan  lvm.static   lvresize    
lvchange     lvextend     lvmdump      lvreduce     lvs         
lvconvert    lvm          lvmsadc      lvremove     lvscan      
lvcreate     lvmchange    lvmsar       lvrename    

[root@rhel5 ~]# lvextend -L +100M /dev/vgwuhan/lvmwuhan
  /dev/cdrom: open failed: Read-only file system
  Extending logical volume lvmwuhan to 300.00 MB
  Logical volume lvmwuhan successfully resized
[root@rhel5 ~]# lvdisplay -v
    Finding all logical volumes
  --- Logical volume ---
  LV Name                /dev/vgwuhan/lvmwuhan
  VG Name                vgwuhan
  LV UUID                E6H3PK-enYT-n1wm-VSax-WIo7-VyiN-1LI5jm
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                300.00 MB
  Current LE             75
  Segments               3
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:0

二、卸载LVM

1、执行lvremove相关命令进行卸载（此时会报错，所以需要首先进行卸载）

[root@rhel5 ~]# lvremove /dev/vgwuhan/lvmwuhan
  /dev/cdrom: open failed: Read-only file system
  Can't remove open logical volume "lvmwuhan"

2、卸载文件系统并卸载逻辑卷
[root@rhel5 ~]# umount /dev/vgwuhan/lvmwuhan
[root@rhel5 ~]# lvremove /dev/vgwuhan/lvmwuhan
  /dev/cdrom: open failed: Read-only file system
Do you really want to remove active logical volume lvmwuhan? [y/n]: y
  Logical volume "lvmwuhan" successfully removed
3、查看卷组信息

[root@rhel5 ~]# vgdisplay -v
    Finding all volume groups
    Finding volume group "vgwuhan"
  --- Volume group ---
  VG Name               vgwuhan
  System ID            
  Format                lvm2
  Metadata Areas        3
  Metadata Sequence No  5
  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               300.00 MB
  PE Size               4.00 MB
  Total PE              75
  Alloc PE / Size       0 / 0  
  Free  PE / Size       75 / 300.00 MB
  VG UUID               MhEO9N-p5p8-SEbm-Dsr9-8WFq-6O33-7U6JNB
  
  --- Physical volumes ---
  PV Name               /dev/sdb1    
  PV UUID               cu9atA-55iM-6eMo-SAi8-ULly-irGI-hKetJk
  PV Status             allocatable
  Total PE / Free PE    25 / 25
  
  PV Name               /dev/sdb2    
  PV UUID               p8jLW1-EXe0-6VHQ-PK5l-gd30-5GbL-7zvJMF
  PV Status             allocatable
  Total PE / Free PE    25 / 25
  
  PV Name               /dev/sdb3    
  PV UUID               qTgWn8-4e6N-qLeX-7jwW-brwv-TRMb-XnnaxP
  PV Status             allocatable
  Total PE / Free PE    25 / 25
4、卸载卷组  
[root@rhel5 ~]# vgremove vgwuhan
  /dev/cdrom: open failed: Read-only file system
  Volume group "vgwuhan" successfully removed
[root@rhel5 ~]# vgdisplay -v
    Finding all volume groups

5、移除物理卷
[root@rhel5 ~]# pvremove /dev/sdb1 /dev/sdb2 /dev/sdb3
  /dev/cdrom: open failed: Read-only file system
  Attempt to close device '/dev/cdrom' which is not open.
  Labels on physical volume "/dev/sdb1" successfully wiped
  /dev/cdrom: open failed: Read-only file system
  Attempt to close device '/dev/cdrom' which is not open.
  Labels on physical volume "/dev/sdb2" successfully wiped
  /dev/cdrom: open failed: Read-only file system
  Attempt to close device '/dev/cdrom' which is not open.
  Labels on physical volume "/dev/sdb3" successfully wiped
[root@rhel5 ~]# pvdisplay