linux LVM配置

續上一章日誌《LVM 簡介》

實例：建立一個LVM

首先分出4個分區,每個分區1.5G左右,且system ID 需要為8e

全部整合成一個VG,VG名稱為aixevg；PE大小改為16M

全部VG轉換為LV,

最終把LV格式化為ext3,並掛載到/mnt/lvm

第一步：建立分區

具體的建立方法,我就不多說了在我的《linux 新加硬碟》中具體講述了的,這個要注意的是：我們使用t來講system ID改為8e.

[root@CentOS5 ~]# fdisk /dev/sdb 
Command (m for help): p 
 
Disk /dev/sdb: 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/sdb1               1        1246    10008463    5  Extended 
/dev/sdb5               1         183     1469884   8e  Linux LVM 
/dev/sdb6             184         366     1469916   8e  Linux LVM 
/dev/sdb7             367         549     1469916   8e  Linux LVM 
/dev/sdb8             550         732     1469916   8e  Linux LVM 
 
Command (m for help): w 
The partition table has been altered! 
 
Calling ioctl() to re-read partition table. 
Syncing disks. 
[root@CentOS5 ~]# partprobe 

第二步：建立PV

[root@CentOS5 ~]# pvcreate /dev/sdb{5,6,7,8} 
  Physical volume "/dev/sdb5" successfully created 
  Physical volume "/dev/sdb6" successfully created 
  Physical volume "/dev/sdb7" successfully created 
  Physical volume "/dev/sdb8" successfully created 
 
[root@CentOS5 ~]# pvscan  
        
                 
  PV /dev/sdb5                      lvm2 [1.40 GB] 
  PV /dev/sdb6                      lvm2 [1.40 GB] 
  PV /dev/sdb7                      lvm2 [1.40 GB] 
  PV /dev/sdb8                      lvm2 [1.40 GB] 
 
[root@CentOS5 ~]# pvdisplay 
  --- NEW Physical volume --- 
  PV Name               /dev/sdb5 
  VG Name                
  PV Size               1.40 GB 
  Allocatable           NO 
  PE Size (KByte)       0 
  Total PE              0 
  Free PE               0 
  Allocated PE          0 
  PV UUID               R4Qnom-CFRz-rt8s-sU0p-D3ze-GbZ0-eU7BZ7 
    
  "/dev/sdb6" is a new physical volume of "1.40 GB" 
  --- NEW Physical volume --- 
  PV Name               /dev/sdb6 
  VG Name                
  PV Size               1.40 GB 
  Allocatable           NO 
  PE Size (KByte)       0 
  Total PE              0 
  Free PE               0 
  Allocated PE          0 
  PV UUID               MYEOVx-o8zH-EbXv-ObHm-F9EY-bA9N-0choil 
…（省略部分）… 

第三步：創建VG

Vgcreate命令格式

[root@CentOS5 ~]# vgcreate [-s N[mgt]] VG名稱 PV名稱 
-s：是設置PV大小選項,它的單位可以是M、G、T 

[root@CentOS5 ~]# vgcreate -s 16M aixevg /dev/sdb{5,6,7} 
  Volume group "aixevg" successfully created 
[root@CentOS5 ~]# vgdisplay  
  --- Volume group --- 
  VG Name               aixevg 
  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               4.17 GB 
  PE Size               16.00 MB 
  Total PE              267 
  Alloc PE / Size       0 / 0    
  Free  PE / Size       267 / 4.17 GB 
  VG UUID               oLaH3J-SGFs-wTTO-bT84-pytG-dSu8-4nfaVe 

第四步：創建

Lvcreate命令格式

[root@CentOS5 ~]# lvcreate [-L N[mgt]] [-n 名稱] VG名稱 
[root@CentOS5 ~]# lvcreate [-l N]] [-n 名稱] VG名稱 
-L：設置LV大小選項,單位是M、G、T 
-l：也是設置LV大小選項,只是-l後面跟的是LV裡面包含多少PV 
-n：設置LV名稱選項 

[root@CentOS5 ~]# lvcreate -l 356 -n aixelv aixevg 
  Logical volume "aixelv" created 
[root@CentOS5 ~]# lvdisplay  
  --- Logical volume --- 
  LV Name                /dev/aixevg/aixelv 
  VG Name                aixevg 
  LV UUID                n0aooF-UaAS-MRlw-JW5F-1gW2-uLkf-R2XHxm 
  LV Write Access        read/write 
  LV Status              available 
  # open                 0 
  LV Size                5.56 GB 
  Current LE             356 
  Segments               4 
  Allocation             inherit 
  Read ahead sectors     auto 
  - currently set to     256 
  Block device           253:2 

第五步：格式化、掛載

[root@CentOS5 ~]# mkfs -t ext3 /dev/aixevg/aixelv 
[root@CentOS5 ~]# mkdir /mnt/lvm 
[root@CentOS5 ~]# mount /dev/aixevg/aixelv /mnt/lvm/ 
[root@CentOS5 ~]# df -h /mnt/lvm/ 
Filesystem            Size  Used Avail Use% Mounted on 
/dev/mapper/aixevg-aixelv 
                      5.5G  140M  5.1G   3% /mnt/lvm 
[root@CentOS5 ~]# cp -a /etc /var /mnt/lvm/ 
[root@CentOS5 ~]# df -h /mnt/lvm/ 
Filesystem            Size  Used Avail Use% Mounted on 
/dev/mapper/aixevg-aixelv 
                      5.5G  321M  4.9G   7% /mnt/lvm 

到這裡我們的LVM已經創建好了,但是像我這樣掛載,在每次重啟伺服器后又需要重新掛載,所以建議大家在/etc/fstab下掛載,或者將命令寫入/etc/rc.local中

日誌字數限制,我會在下一章日誌中講解LVM的延伸與縮減