在linux下如何把一个lvm的文件系统减小

在linux下如何把一个lvm的文件系统/home减到1G。比aix下麻烦，aix下直接把文件系统缩到某个值，对应的lv自动就减少了，不像linux要先缩小文件系统，再缩小lv。

suse1:~ # df -m

Filesystem           1M-blocks      Used Available Use% Mounted on

/dev/mapper/system-root

                          5040      2998      1787  63% /

udev                       125         1       125   1% /dev

/dev/sda1                   69        18        48  28% /boot

/dev/mapper/system-home

                          6493       146      6018   3% /home

resize2fs以4k block为单位，1G=262144 * 4K

步骤如下

umount /home
e2fsck -f /dev/mapper/system-home
resize2fs /dev/mapper/system-home 262144
lvchange -an /dev/system/home
lvreduce -L1G /dev/system/home
lvchange -ay /dev/system/home
mount /home

详细输出如下

suse1:~ # resize2fs /dev/mapper/system-home 262144
resize2fs 1.40.8 (13-Mar-2008)
Please run 'e2fsck -f /dev/mapper/system-home' first.

suse1:~ # e2fsck -f /dev/mapper/system-home
e2fsck 1.40.8 (13-Mar-2008)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/mapper/system-home: 663/130048 files (0.5% non-contiguous), 44176/524288 blocks
suse1:~ # resize2fs /dev/mapper/system-home 262144
resize2fs 1.40.8 (13-Mar-2008)
Resizing the filesystem on /dev/mapper/system-home to 262144 (4k) blocks.
The filesystem on /dev/mapper/system-home is now 262144 blocks long.
suse1:~ # lvchange -an /dev/system/home
suse1:~ # lvreduce -L1G /dev/system/home
  Reducing logical volume home to 1.00 GB
  Logical volume home successfully resized
suse1:~ # mount /home
mount: special device /dev/system/home does not exist
suse1:~ # lvchange -ay /dev/system/home
suse1:~ # mount /home
suse1:~ # vgdisplay 
  --- Volume group ---
  VG Name               system
  System ID             
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  6
  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               11.93 GB
  PE Size               4.00 MB
  Total PE              3053
  Alloc PE / Size       1660 / 6.48 GB
  Free  PE / Size       1393 / 5.44 GB
  VG UUID               sSr6Nu-Xpy0-YtLy-kx0g-dAS1-oLks-WNpfjV