场景：sdb之前是3G容量，现在扩容了sdb的容量到8G。现在把新扩容的5G容量扩展到现有的逻辑卷中


[root@localhost ~]# pvresize /dev/sdb
  Physical volume "/dev/sdb" changed
  1 physical volume(s) resized / 0 physical volume(s) not resized




[root@localhost ~]# pvdisplay
  --- Physical volume ---
  PV Name               /dev/sdb
  VG Name               domuvg
  PV Size               8.00 GiB / not usable 3.00 MiB
  Allocatable           yes
  PE Size               4.00 MiB
  Total PE              2047
  Free PE               1280
  Allocated PE          767
  PV UUID               Do2B23-Mg1v-z5JX-6NoJ-sXIk-Smwy-uR7IoE



[root@localhost ~]# vgdisplay
  --- Volume group ---
  VG Name               domuvg
  System ID             
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  6
  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               8.00 GiB
  PE Size               4.00 MiB
  Total PE              2047
  Alloc PE / Size       767 / 3.00 GiB
  Free  PE / Size       1280 / 5.00 GiB
  VG UUID               4Shwbf-0m2N-3icW-cEil-6W5x-JNLS-bXCZ7W



[root@localhost ~]# lvextend -l +100%FREE /dev/domuvg/alidata
  Size of logical volume domuvg/alidata changed from 2.00 GiB (511 extents) to 7.00 GiB (1791 extents).
  Logical volume alidata successfully resized


[root@localhost ~]# lvdisplay
  --- Logical volume ---
  LV Path                /dev/domuvg/swap
  LV Name                swap
  VG Name                domuvg
  LV UUID                xZdi63-3wLm-rKE5-1EYh-0Q7p-bHZM-oibkoj
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2015-10-08 15:10:14 +0800
  LV Status              available
  # open                 1
  LV Size                1.00 GiB
  Current LE             256
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:0
   
  --- Logical volume ---
  LV Path                /dev/domuvg/alidata
  LV Name                alidata
  VG Name                domuvg
  LV UUID                g2pjLY-epuy-2Ba0-eBLc-EjIr-sSAO-mt8VOF
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2015-10-08 15:10:15 +0800
  LV Status              available
  # open                 1
  LV Size                7.00 GiB
  Current LE             1791
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:1



[root@localhost ~]# resize2fs /dev/domuvg/alidata
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/domuvg/alidata is mounted on /alidata; on-line resizing required
old desc_blocks = 1, new_desc_blocks = 1
Performing an on-line resize of /dev/domuvg/alidata to 1833984 (4k) blocks.
The filesystem on /dev/domuvg/alidata is now 1833984 blocks long.



[root@localhost ~]# df -Ph
Filesystem                  Size  Used Avail Use% Mounted on
/dev/sda2                   7.3G 1020M  5.9G  15% /
tmpfs                       939M     0  939M   0% /dev/shm
/dev/mapper/domuvg-alidata  6.9G  4.5M  6.6G   1% /alidata