linux下磁盘管理之利器 lvm使用介绍(2)

[root@stau11 ~]# fdisk -l //查看分区的情况
[root@stau11 ~]# fdisk /dev/sda //进行分区
Command (m for help): n //n为添加一个分区，p查看分区
First cylinder (2898-10443, default 2898): //按【Enter】键决定
Using default value 2898 //起始柱面选择默认 值
Last cylinder or +size or +sizeM or +sizeK (289810443, default 10443): +2G // 给2G的大小
Command (m for help): t //更改分区类型
Partition number (1-5): 5 //选着分区
Hex code (type L to list codes): l //分区类型列表
Hex code (type L to list codes):8e //将新添加的分区标注成lvm
Command (m for help): p //查看分区表
/dev/sda5 2756 2999 1959898+ 8e Linux LVM
Command (m for help): w //保存
[root@localhost ~]# partprobe /dev/sda //是系统识别分区（代替重启）
[root@localhost ~]# mkfs.ext3 /dev/sda5 //格式化新添加的分区

[root@localhost ~]# pvcreate /dev/sda5 //创建pv
Writing physical volume data to disk "/dev/sda5"
Physical volume "/dev/sda5" successfully created
[root@localhost ~]# pvs //查看当前pv的信息
PV VG Fmt Attr PSize PFree
/dev/sda5 lvm2 a-- 1.87G 1.87G

[root@localhost ~]# vgcreate vg0 /dev/sda5 //vg0为当前vg的名
Volume group "vg0" successfully created
[root@localhost ~]# vgs //查看vg的信息
VG #PV #LV #SN Attr VSize VFree
vg0 1 0 0 wz--n- 1.87G 1.87G

[root@localhost ~]# lvcreate -L 500M -n lv01 vg0
Logical volume "lv01" created
[root@localhost ~]# lvs //查看lv的信息
LV VG Attr LSize Origin Snap% Move Log Copy% Convert
lv01 vg0 -wi-a- 500.00M
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[root@localhost ~]# mkfs.ext3 /dev/vg0/lv01 //格式化

[root@localhost ~]# lvextend -L +300M /dev/vg0/lv01 //(原来lv大小500M ，拉伸分区到 800M) Extending logical volume lv01 to 800.00 MB
Logical volume lv01 successfully resized
[root@localhost ~]# resize2fs /dev/vg0/lv01 //拉伸文件系统
[root@localhost ~]# lvs
LV VG Attr LSize Origin Snap% Move Log Copy% Convert
lv01 vg0 -wi-ao 800.00M //大小变成了800M

# umount /dev/vg0/lv01 //卸载逻辑卷/dev/vg0/lv01
# df -h //查看
# e2fsck -f /dev/vg0/lv01 //磁盘校验
# resize2fs /dev/vg0/lv01 500M //回缩文件系统到 500M
# lvreduce -L 500M /dev/vg0/lv01 //回缩分区到 500M
WARNING: Reducing active logical volume to 500.00 MB
THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce lv01? [y/n]: y
# lvs
LV VG Attr LSize Origin Snap% Move Log Copy% Convert
lv01 vg0 -wi-a- 500.00M //此时已变成500M大小
# mount /dev/vg0/lv01 /mnt/lv01 //重新挂载分区
# df -h //查看
# ls /mnt/lv01 //查看文件

[root@localhost ~] # mount /dev/vg0/lv01 /mnt/lv01
[root@localhost ~]# cd /mnt/lv01
[root@localhost lv01]# touch {a,b,c}{a,b,c}
[root@localhost lv01]# ls
aa ab ac ba bb bc ca cb cc lost+found lv.file restoresymtable

[root@localhost lv01]# lvcreate -L 64M -s -n lv-backup /dev/vg0/lv01
Logical volume "lv-backup" created