LVM逻辑卷基本操作

相关命令

• pvcreate /dev/sdb //创建物理卷(VGDA:卷组描述区域)
  • pvscan, pvdisplay //扫瞄，显示物理卷
  • pvremove /dev/sdb //删除物理卷

[root@KMVS-CENTOS shm]# pvdisplay 
  --- Physical volume ---
  PV Name               /dev/sda2
  VG Name               vg_kmvscentos
  PV Size               79.51 GiB / not usable 3.00 MiB
  Allocatable           yes (but full)
  PE Size               4.00 MiB
  Total PE              20354
  Free PE               0
  Allocated PE          20354
  PV UUID               Ggncx1-y0eb-XVyQ-6jxi-SX35-tzbp-rSeJHP

• vgdisplay 查看卷组，vgcreate 创建卷组
  • vgcreate <volume-group1卷组名> /dev/sdb1 /dev/sdb2 /dev/sdb3
  • vgremove <volume-group1> //删除卷组
  • vgchange -a y // 激活所有卷组
  • vgextend <volume-group1> <pv-path> //增大卷组，把新的物理卷加入现在卷组
  • vgreduce <volume-group1> <pv-path>//减小卷组，把物理卷从卷组中移出

[root@KMVS-CENTOS shm]# vgdisplay 
  --- Volume group ---
  VG Name               vg_kmvscentos
  System ID             
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  4
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                3
  Open LV               3
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               79.51 GiB
  PE Size               4.00 MiB
  Total PE              20354
  Alloc PE / Size       20354 / 79.51 GiB
  Free  PE / Size       0 / 0   
  VG UUID               HbeVkk-bnpi-O4NZ-aGzQ-N8jy-D8rZ-QNcqgD

• lvcreate -L 100M -n <lv1逻辑卷名> <volume-group1卷组名> //创建逻辑卷
  • lvdisplay
  • lvremove /dev/volume-group1/lv1 //删除逻辑卷
  • lvresize -L 200M /dev/volume-group1/lv1 // 增大，或 缩小逻辑卷大小
  • lvextend -L|--size +逻辑卷大小增量 逻辑卷全路径名 //增大
  • lvreduce q -L|--size +逻辑卷减小量 逻辑卷全路径名 //缩小
  • lvchange -an <logical volume path> //inactive 逻辑卷
  • lvchange -ay <logical volume path>//active 激活逻辑卷

[root@KMVS-CENTOS shm]# lvdisplay 
  --- Logical volume ---
  LV Path                /dev/vg_kmvscentos/lv_home
  LV Name                lv_home
  VG Name                vg_kmvscentos
  LV UUID                UoK2Gc-Y1Ec-lJXr-Vv57-xAkc-iZsz-HaAtNV
  LV Write Access        read/write
  LV Creation host, time KMVS-CENTOS, 2013-08-08 12:25:46 +0800
  LV Status              available
  # open                 1
  LV Size                25.63 GiB
  Current LE             6562
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:2

• 格式化逻辑卷
  • sudo mkfs.ext4 /dev/mapper/dataVG-data
• 每次开机自动挂载
  • echo "/dev/mapper/dataVG-data /data ext4 defaults,noatime,barrier=0,data=writeback 0 0" | sudo tee -a /etc/fstab
• 建立/data目录，不然挂载不上
  • sudo mkdir /data

不重启，显示新硬盘

• 确定主机总线号：

[root@KMVS-CENTOS shm]# ls /sys/class/scsi_host/
host0  host1  host2

• 重新扫描SCSI总线来添加设备：

 [root@iNeedle~]# echo "- - -" > /sys/class/scsi_host/host0/scan
 [root@iNeedle~]# echo "- - -" > /sys/class/scsi_host/host1/scan
 [root@iNeedle~]# echo "- - -" > /sys/class/scsi_host/host2/scan

• fdisk -l

Disk /dev/sdb: 32.2 GB, 32212254720 bytes
255 heads, 63 sectors/track, 3916 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

添加新硬盘，纳入逻辑卷

• create物理卷

[root@KMVS-CENTOS shm]# pvcreate  /dev/sdb 
  Physical volume "/dev/sdb" successfully created

• 扩充逻辑卷

[root@KMVS-CENTOS shm]# vgextend vg_kmvscentos /dev/sdb
  Volume group "vg_kmvscentos" successfully extended
[root@KMVS-CENTOS shm]# vgdisplay 
  --- Volume group ---
  VG Name               vg_kmvscentos
  System ID             
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  5
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                3
  Open LV               3
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               109.50 GiB
  PE Size               4.00 MiB
  Total PE              28033
  Alloc PE / Size       20354 / 79.51 GiB
  Free  PE / Size       7679 / 30.00 GiB
  VG UUID               HbeVkk-bnpi-O4NZ-aGzQ-N8jy-D8rZ-QNcqgD

• 给特定逻辑卷增加容量

[root@KMVS-CENTOS shm]# lvresize -L 30G /dev/mapper/vg_kmvscentos-lv_home 
  Extending logical volume lv_home to 30.00 GiB
  Logical volume lv_home successfully resized
    
[root@KMVS-CENTOS shm]# lvextend -L   +25.6G  /dev/mapper/vg_kmvscentos-lv_home 
  Rounding size to boundary between physical extents: 25.60 GiB
  Extending logical volume lv_home to 55.60 GiB
  Logical volume lv_home successfully resized

• resize2fs /dev/mapper/vg_kmvscentos-lv_home

[root@KMVS-CENTOS shm]# resize2fs /dev/mapper/vg_kmvscentos-lv_home 
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/mapper/vg_kmvscentos-lv_home is mounted on /home; on-line resizing required
old desc_blocks = 2, new_desc_blocks = 4
Performing an on-line resize of /dev/mapper/vg_kmvscentos-lv_home to 14582784 (4k) blocks.
The filesystem on /dev/mapper/vg_kmvscentos-lv_home is now 14582784 blocks long.

[root@KMVS-CENTOS shm]# df -h
文件系统          容量  已用  可用 已用%% 挂载点
/dev/mapper/vg_kmvscentos-lv_root
                       50G   14G   33G  30% /
tmpfs                 7.9G  292K  7.9G   1% /dev/shm
/dev/sda1             485M   38M  423M   9% /boot
/dev/mapper/vg_kmvscentos-lv_home
                       55G   20G   33G  39% /home
/dev/sda3             119G   13G  101G  11% /disk