Extending and Reducing LV in LINUX

Lets extend the size of  testlv

[root@localhost ~]# lvdisplay /dev/testvg/testlv

  --- Logical volume ---

  LV Name                /dev/testvg/testlv

  VG Name                testvg

  LV UUID                jFiX1B-SL0k-bZZ3-yHMb-zO4h-OySU-1Sw3a9

  LV Write Access        read/write

  LV Status              available

  # open                 0

  LV Size                100.00 MB

  Current LE             25

  Segments               1

  Allocation             inherit

  Read ahead sectors     auto

  - currently set to     256

  Block device           253:0

[root@localhost ~]# umount /dev/testvg/testlv 

[root@localhost ~]# fsck -f /dev/testvg/testlv 

fsck 1.39 (29-May-2006)

e2fsck 1.39 (29-May-2006)

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/testvg/testlv: 11/25792 files (9.1% non-contiguous), 8927/102400 blocks

[root@localhost ~]# lvextend -L +150M /dev/testvg/testlv 

  Rounding up size to full physical extent 152.00 MB

  Extending logical volume testlv to 252.00 MB

  Logical volume testlv successfully resized

[root@localhost ~]# resize2fs /dev/testvg/testlv 

resize2fs 1.39 (29-May-2006)

Resizing the filesystem on /dev/testvg/testlv to 258048 (1k) blocks.

The filesystem on /dev/testvg/testlv is now 258048 blocks long.

[root@localhost ~]# lvdisplay /dev/testvg/testlv 

  --- Logical volume ---

  LV Name                /dev/testvg/testlv

  VG Name                testvg

  LV UUID                jFiX1B-SL0k-bZZ3-yHMb-zO4h-OySU-1Sw3a9

  LV Write Access        read/write

  LV Status              available

  # open                 0

  LV Size                252.00 MB

  Current LE             63

  Segments               1

  Allocation             inherit

  Read ahead sectors     auto

  - currently set to     256

  Block device           253:0

****************************************************

After we are done with increasing the size of testlv, let's reduce the size of testlv

[root@localhost ~]# umount /dev/testvg/testlv

[root@localhost ~]# fsck -f /dev/testvg/testlv

fsck 1.39 (29-May-2006)

e2fsck 1.39 (29-May-2006)

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/testvg/testlv: 11/63488 files (9.1% non-contiguous), 14193/258048 blocks

[root@localhost ~]# resize2fs /dev/testvg/testlv 150M

resize2fs 1.39 (29-May-2006)

Resizing the filesystem on /dev/testvg/testlv to 153600 (1k) blocks.

The filesystem on /dev/testvg/testlv is now 153600 blocks long.

[root@localhost ~]# lvreduce -L 150M /dev/testvg/testlv 

  Rounding up size to full physical extent 152.00 MB

  WARNING: Reducing active logical volume to 152.00 MB

  THIS MAY DESTROY YOUR DATA (filesystem etc.)

Do you really want to reduce testlv? [y/n]: y

  Reducing logical volume testlv to 152.00 MB

  Logical volume testlv successfully resized

[root@localhost ~]# lvdisplay /dev/testvg/testlv 

  --- Logical volume ---

  LV Name                /dev/testvg/testlv

  VG Name                testvg

  LV UUID                jFiX1B-SL0k-bZZ3-yHMb-zO4h-OySU-1Sw3a9

  LV Write Access        read/write

  LV Status              available

  # open                 0

  LV Size                152.00 MB

  Current LE             38

  Segments               1

  Allocation             inherit

  Read ahead sectors     auto

  - currently set to     256

  Block device           253:0

(have u noticed the sequence of commands: lvextend and resize2fs commands are in different order for two different operations. Keep only one thing in mind, resize2fs should be run before lvextend while reducing the size of LV )