linux 为 逻辑卷管理 增加磁盘空间

1.问题

linux使用逻辑卷管理磁盘空间，现在磁盘空间不足：

[root@test1 log]# df -h
Filesystem                    Size  Used Avail Use% Mounted on
/dev/mapper/vg_test1-lv_root   16G   15G   16M 100% /
tmpfs                         499M  224K  498M   1% /dev/shm
/dev/sda1                     485M   35M  426M   8% /boot

2.确认
[root@test1 log]# lvdisplay     #确认vg_test1-lv_root确认是逻辑卷
  --- Logical volume ---
  LV Path                /dev/vg_test1/lv_root
  LV Name                lv_root
  VG Name                vg_test1
  LV UUID                Kvt5rT-03rj-dnfn-kpNA-1Ham-ZPzh-kuBAO9
  LV Write Access        read/write
  LV Creation host, time test1, 2016-05-11 10:56:46 +0800
  LV Status              available
  # open                 1
  LV Size                15.71 GiB
  Current LE             4022
  Segments               2
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:0
   
  --- Logical volume ---
  LV Path                /dev/vg_test1/lv_swap
  LV Name                lv_swap
  VG Name                vg_test1
  LV UUID                aeULjI-OeNe-eNjr-iGE0-Wz2O-4bXA-3Kb8n4
  LV Write Access        read/write
  LV Creation host, time test1, 2016-05-11 10:56:47 +0800
  LV Status              available
  # open                 1
  LV Size                816.00 MiB
  Current LE             204
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:1

3.加磁盘

[root@test1 log]# shutdown -h now

Broadcast message from root@test1
(/dev/pts/2) at 6:19 ...

The system is going down for halt NOW!

这里用的是Oracle VM VirtualBox，加块磁盘如下：

设置->存储->控制器 SATA->添加 虚拟 磁盘->创建新的虚拟盘->类型选VDI->动态分配大小->起个名字，调整好大小，点创建->启动虚拟机

[root@test1 ~]# fdisk -l     #看一下有没有新加的磁盘

Disk /dev/sda: 8589 MB, 8589934592 bytes
255 heads, 63 sectors/track, 1044 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: 0x00093d66

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          64      512000   83  Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2              64        1045     7875584   8e  Linux LVM

Disk /dev/sdb: 10.7 GB, 10737418240 bytes
255 heads, 63 sectors/track, 1305 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: 0xb7312e9f

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1        1305    10482381   83  Linux

Disk /dev/sdc: 8589 MB, 8589934592 bytes     #这就是我们刚加的磁盘，大小8G
255 heads, 63 sectors/track, 1044 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

Disk /dev/mapper/vg_test1-lv_root: 16.9 GB, 16869490688 bytes
255 heads, 63 sectors/track, 2050 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

Disk /dev/mapper/vg_test1-lv_swap: 855 MB, 855638016 bytes
255 heads, 63 sectors/track, 104 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

[root@test1 ~]# fdisk /dev/sdc     #分区
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0x27410e25.
Changes will remain in memory only, until you decide to write them.
After that, of course, the previous content won't be recoverable.


Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)


WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
         switch off the mode (command 'c') and change display units to
         sectors (command 'u').


Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-1044, default 1): 
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-1044, default 1044): 
Using default value 1044


Command (m for help): w
The partition table has been altered!


Calling ioctl() to re-read partition table.
Syncing disks.

[root@test1 ~]# fdisk -l     #验证一下，这时会看到分区/dev/sdc1

4.扩展空间

[root@test1 ~]# pvcreate /dev/sdc1     #创建物理卷
  Physical volume "/dev/sdc1" successfully created
[root@test1 ~]# pvdisplay     #验证

[root@test1 ~]# pvs     #验证，也可以使用pvdisplay
  PV         VG       Fmt  Attr PSize PFree   
  /dev/sda2  vg_test1 lvm2 a--  7.51g       0 
  /dev/sdb1  vg_test1 lvm2 a--  9.99g 1016.00m
  /dev/sdc1           lvm2 a--  8.00g    8.00g

[root@test1 ~]# lvs     #确认要扩展空间的逻辑卷所属的卷组
  LV      VG       Attr       LSize   Pool Origin Data%  Move Log Cpy%Sync Convert
  lv_root vg_test1 -wi-ao----  15.71g                                             
  lv_swap vg_test1 -wi-ao---- 816.00m                

[root@test1 ~]# vgextend vg_test1 /dev/sdc1     #扩展卷
  Volume group "vg_test1" successfully extended

[root@test1 ~]# vgs     #验证
  VG       #PV #LV #SN Attr   VSize  VFree
  vg_test1   3   2   0 wz--n- 25.50g 8.99g

[root@test1 ~]# lvs
  LV      VG       Attr       LSize   Pool Origin Data%  Move Log Cpy%Sync Convert
  lv_root vg_test1 -wi-ao----  15.71g                                             
  lv_swap vg_test1 -wi-ao---- 816.00m                                             
[root@test1 ~]# lvextend -L +8.99g /dev/vg_test1/lv_root 
  Rounding size to boundary between physical extents: 8.99 GiB
  Extending logical volume lv_root to 24.70 GiB
  Insufficient free space: 2302 extents needed, but only 2301 available     #报错，因为加大了
[root@test1 ~]# lvs
  LV      VG       Attr       LSize   Pool Origin Data%  Move Log Cpy%Sync Convert
  lv_root vg_test1 -wi-ao----  15.71g     #没加成功                                             
  lv_swap vg_test1 -wi-ao---- 816.00m                                             
[root@test1 ~]# lvextend -L +8.90g /dev/vg_test1/lv_root 
  Rounding size to boundary between physical extents: 8.90 GiB
  Extending logical volume lv_root to 24.61 GiB
  Logical volume lv_root successfully resized
[root@test1 ~]# lvs
  LV      VG       Attr       LSize   Pool Origin Data%  Move Log Cpy%Sync Convert
  lv_root vg_test1 -wi-ao----  24.61g     #加成功                                             
  lv_swap vg_test1 -wi-ao---- 816.00m                

[root@test1 ~]# df -h
Filesystem                    Size  Used Avail Use% Mounted on
/dev/mapper/vg_test1-lv_root   16G   15G   18M 100% /    #大小没变，需要resize下逻辑卷才行
tmpfs                         499M   72K  499M   1% /dev/shm
/dev/sda1                     485M   35M  426M   8% /boot
[root@test1 ~]# resize2fs /dev/vg_test1/lv_root 
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/vg_test1/lv_root is mounted on /; on-line resizing required
old desc_blocks = 1, new_desc_blocks = 2
Performing an on-line resize of /dev/vg_test1/lv_root to 6452224 (4k) blocks.
The filesystem on /dev/vg_test1/lv_root is now 6452224 blocks long.

[root@test1 ~]# df -h
Filesystem                    Size  Used Avail Use% Mounted on
/dev/mapper/vg_test1-lv_root   25G   15G  8.4G  64% /    #OK，加空间完成。
tmpfs                         499M   72K  499M   1% /dev/shm
/dev/sda1                     485M   35M  426M   8% /boot
[root@test1 ~]#