Linux 磁盘管理 五（Raid、LVM、Quota）

3、调整LVM卷（添加一块大小为1G，类型为SCSI的磁盘）
3-1调整卷组
3-1-1、查看VG和空闲PV

[root@localhost ~]# vgdisplay LVMonRaid | grep 'VG Size'
VG Size 2.98 GB
[root@localhost ~]# pvdisplay /dev/sdf1 | grep 'PV Size'
PV Size 1019.72 MB
3-1-2、把物理卷/dev/sdf1加入到卷组LVMonRaid中

[root@localhost ~]# vgextend LVMonRaid /dev/sdf1
Attempt to close device '/dev/cdrom' which is not open.
Volume group "LVMonRaid" successfully extended
[root@localhost ~]# vgdisplay LVMonRaid | grep 'VG Size'
VG Size 3.97 GB

3-1-3、把物理卷/dev/sdf1从卷组LVMonRaid中卸载

[root@localhost ~]# vgreduce LVMonRaid /dev/sdf1
Removed "/dev/sdf1" from volume group "LVMonRaid"
[root@localhost ~]# vgdisplay LVMonRaid | grep 'VG Size'
VG Size 2.98 GB

3-2、调整逻辑卷
注意：实际工作中在进行逻辑卷调整时，应做好备份，避免错误的命令做好数据的丢失；另外使用resize2fs缩小文件系统时，要先umount文件文件系统，而且必须保证文件系统使用量，必须小于缩小后的大小；放大文件系统，可直接操作，不受上述限制。
3-2-1、查看文件系统和LV的大小

[root@localhost ~]# tune2fs -l /dev/LVMonRaid/LogicLV1 | grep Block
Block count: 262144
Block size: 4096
Blocks per group: 32768
[root@localhost ~]# lvdisplay /dev/LVMonRaid/LogicLV1 | grep 'LV Size'
LV Size 1.00 GB

3-2-2、LV增加100M，再次查看文件系统和LV的大小

[root@localhost ~]# lvextend -L +100M /dev/LVMonRaid/LogicLV1
Extending logical volume LogicLV1 to 1.10 GB
Logical volume LogicLV1 successfully resized
[root@localhost ~]# tune2fs -l /dev/LVMonRaid/LogicLV1 | grep Block
Block count: 262144
Block size: 4096
Blocks per group: 32768
[root@localhost ~]# lvdisplay /dev/LVMonRaid/LogicLV1 | grep 'LV Size'
LV Size 1.10 GB
文件系统大小没有变，LV大小增加了100M

3-2-3、放大文件系统，并查看其改变

[root@localhost ~]# resize2fs -f /dev/LVMonRaid/LogicLV1
resize2fs 1.39 (29-May-2006)
Resizing the filesystem on /dev/LVMonRaid/LogicLV1 to 287744 (4k) blocks.
resize2fs: Can't read an block bitmap while trying to resize /dev/LVMonRaid/LogicLV1
[root@localhost ~]# tune2fs -l /dev/LVMonRaid/LogicLV1 | grep Block
Block count: 307200
Block size: 4096
Blocks per group: 32768

3-2-4、缩小LV

[root@localhost ~]# lvreduce -L 1G /dev/LVMonRaid/LogicLV1
/dev/cdrom: open failed: 只读文件系统
WARNING: Reducing active logical volume to 1.00 GB
THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce LogicLV1? [y/n]: y
Reducing logical volume LogicLV1 to 1.00 GB
Logical volume LogicLV1 successfully resized

4、LVM的高级应用
4-1、卷快照
4-1-1、创建/dev/LVMonRaid/LogicLV1的卷快照bakLV1

[root@localhost ~]# lvcreate -L 500M -s -n bakLV1 /dev/LVMonRaid/LogicLV1
Logical volume "bakLV1" created

4-1-2、读取逻辑卷快照

做快照时LV上的数据
[root@localhost ~]# mount /dev/LVMonRaid/LogicLV1 /mnt/lv1
[root@localhost mnt]# ll /mnt/lv1
总计 32
-rw------- 1 root root 7168 08-23 23:46 aquota.group
-rw------- 1 root root 8192 08-23 23:31 aquota.user
drwxrwxrwx 2 root root 16384 08-22 20:38 lost+found

快照上的数据
[root@localhost ~]# mount /dev/LVMonRaid/bakLV1 /mnt/lvbak/
[root@localhost ~]# ll /mnt/lvbak/
总计 32
-rw------- 1 root root 7168 08-23 23:46 aquota.group
-rw------- 1 root root 8192 08-23 23:31 aquota.user
drwxrwxrwx 2 root root 16384 08-22 20:38 lost+found

4-1-3、卸载卷快照

[root@localhost mnt]# umount /mnt/lvbak/
[root@localhost mnt]# lvremove /dev/LVMonRaid/bakLV1
Do you really want to remove active logical volume bakLV1? [y/n]: y
Logical volume "bakLV1" successfully removed

4-2、移动卷
4-2-1、查看PV空间

[root@localhost mnt]# pvscan
PV /dev/md1 VG LVMonRaid lvm2 [1016.00 MB / 0 free]
PV /dev/md5 VG LVMonRaid lvm2 [1.99 GB / 1004.00 MB free]
PV /dev/sdf1 VG LVMonRaid lvm2 [1016.00 MB / 1016.00 MB free]
Total: 3 [3.97 GB] / in use: 3 [3.97 GB] / in no VG: 0 [0 ]

4-2-2、移动/dev/md1 到/dev/sdf1后，再查看PV空间

[root@localhost mnt]# pvmove /dev/md1 /dev/sdf1
/dev/md1: Moved: 100.0%
[root@localhost mnt]# pvscan
PV /dev/md1 VG LVMonRaid lvm2 [1016.00 MB / 1016.00 MB free]
PV /dev/md5 VG LVMonRaid lvm2 [1.99 GB / 1004.00 MB free]
PV /dev/sdf1 VG LVMonRaid lvm2 [1016.00 MB / 0 free]
Total: 3 [3.97 GB] / in use: 3 [3.97 GB] / in no VG: 0 [0 ]

5、删除LVM（请在做完磁盘配额实验后进行下面删除的实验）
5-1、删除LV

[root@localhost ~]# umount /mnt/lv1
[root@localhost ~]# umount /mnt/lv2
[root@localhost ~]# lvremove /dev/LVMonRaid/LogicLV1
Do you really want to remove active logical volume LogicLV1? [y/n]: y
Logical volume "LogicLV1" successfully removed
[root@localhost ~]# lvremove /dev/LVMonRaid/LogicLV2
Do you really want to remove active logical volume LogicLV2? [y/n]: y
Logical volume "LogicLV2" successfully removed

5-2、删除VG

[root@localhost mnt]# vgremove LVMonRaid
Volume group "LVMonRaid" successfully removed

5-3、删除PV

[root@localhost mnt]# pvremove /dev/md1
Labels on physical volume "/dev/md1" successfully wiped
[root@localhost mnt]# pvremove /dev/md5
Labels on physical volume "/dev/md5" successfully wiped

本文出自 “大海无量” 博客，请务必保留此出处http://hky008.blog.51cto.com/803965/465360