CentOS 5 LVM 在線擴容根分區

說明：
Linux 2.6以上內核支持ext3的在線擴容

第一種狀況：直接添加一個新硬盤
# df -h 看看如今硬盤的狀況
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/VolGroup00-LogVol00
                      6.7G  5.2G  1.3G  81% /
/dev/sda1              99M   12M   82M  13% /boot
tmpfs                 633M     0  633M   0% /dev/shm
# fdisk -l 能夠看到新添加的硬盤/dev/sdb
Disk /dev/sda: 8589 MB, 8589934592 bytes
255 heads, 63 sectors/track, 1044 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          13      104391   83  Linux
/dev/sda2              14        1044     8281507+  8e  Linux LVM

Disk /dev/sdb: 8589 MB, 8589934592 bytes
255 heads, 63 sectors/track, 1044 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/sdb doesn't contain a valid partition table
# lvm
lvm>vgdisplay 能夠先看卷組是否還有剩餘空間能夠擴展，有的話直接擴展，沒有或不夠的話把新的硬盤添加進去
  --- Volume group ---
  VG Name               VolGroup00
  System ID            
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  3
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                2
  Open LV               2
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               7.88 GB
  PE Size               32.00 MB
  Total PE              252
  Alloc PE / Size       252 / 7.88 GB
  Free  PE / Size       0 / 0  
  VG UUID               0U8dPB-UTJZ-Mdv5-eZJM-Xj7f-gR1M-63BcCh
lvm>pvcreate /dev/sdb  使用新的整個硬盤建立一個lvm物理卷
lvm>vgextend /dev/VolGroup00 /dev/sdb  把新的物理卷添加到卷組中
lvm>vgdisplay 能夠看到已分配空間和剩餘未分配空間 All PE / Size 和 Free PE / Size
 --- Volume group ---
  VG Name               VolGroup00
  System ID            
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  4
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                2
  Open LV               2
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               15.84 GB
  PE Size               32.00 MB
  Total PE              507
  Alloc PE / Size       252 / 7.88 GB
  Free  PE / Size       255 / 7.97 GB
  VG UUID               0U8dPB-UTJZ-Mdv5-eZJM-Xj7f-gR1M-63BcCh
lvm>lvextend -L +7.9G /dev/VolGroup00/LogVol00 擴展邏輯卷大小
lvm>vgdisplay
lvm>pvdisplay
lvm>lvdisplay 能夠看到已經添加了
 --- Logical volume ---
  LV Name                /dev/VolGroup00/LogVol00
  VG Name                VolGroup00
  LV UUID                QtNkTM-TeSo-WnZD-fSUr-6k1F-5aLX-zAIfSQ
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                14.78 GB
  Current LE             473
  Segments               2
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:0
  
  --- Logical volume ---
  LV Name                /dev/VolGroup00/LogVol01
  VG Name                VolGroup00
  LV UUID                bhTEBX-t8XK-zGku-NCzx-eolz-Anvj-jUMUER
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                1.00 GB
  Current LE             32
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:1
lvm>quit
# resize2fs -p /dev/VolGroup00/LogVol00  修改文件系統大小以實現擴充空間
# df -h

第二種狀況：只添加一個新分區
# df -h 能夠看到新添加的硬盤/dev/sdb1
# lvm
lvm>pvcreate /dev/sdb1  使用新的硬盤建立一個lvm物理卷
lvm>vgextend /dev/VolGroup00 /dev/sdb1
lvm>vgdisplay 能夠看到已分配空間和剩餘未分配空間 All PE / Size 和 Free PE / Size
lvm>lvextend -L +5G /dev/VolGroup00/LogVol00
lvm>vgdisplay
lvm>pvdisplay
lvm>lvdisplay
lvm>quit
# resize2fs -p /dev/VolGroup00/LogVol00  擴展
# df -h