LVM Resize – How to Increase an LVM Partition

Here we show you how to expand an LVM volume or partition in Linux by first resizing logical volume followed by resizing the file system to take advantage of the additional space.

See here if you’re instead trying to do the opposite and shrink an LVM volume.

Note: In this example we are working in CentOS 7, some commands may differ in different Linux distributions.

In this example we will work through expanding logical volume /var/centos/var from 5GB to 10GB. We currently have this logical volume mounted to /mnt.

Overview of Logical Volume Manager (LVM)

Before working through the resizing process it’s important you first understand some basic concepts around physical volumes, volume groups, logical volumes, and the file system.

  • Physical Volume (PV): This can be created on a whole physical disk (think /dev/sda) or a Linux partition.
  • Volume Group (VG): This is made up of at least one or more physical volumes.
  • Logical Volume (LV): This is sometimes referred to as the partition, it sits within a volume group and has a file system written to it.
  • File System: A file system such as ext4 will be on the logical volume.

LVM Resize – How to increase or expand the logical volume

This process is extremely easy to do with LVM as it can be done on the fly with no downtime needed, you can perform it on a mounted volume without interruption. In order to increase the size of a logical volume, the volume group that it is in must have free space available.

To view the free space of your volume group, run vgdisplay command as shown below and look at the “Free PE / Size” field.

[root@CentOS7 ~]# vgdisplay
  --- Volume group ---
  VG Name               centos
  System ID
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  6
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                3
  Open LV               2
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               20.74 GiB
  PE Size               4.00 MiB
  Total PE              5309
  Alloc PE / Size       4030 / 15.74 GiB
  Free  PE / Size       1280 / 5.00 GiB
  VG UUID               VvG6Sp-wIgb-LTh0-szdU-s9R1-a6K9-qHassI

In this example we have 5GB of free space in the volume group, as shown by “Free PE / Size 1279 / 5.00 GiB”.

Note: If you do not have any or enough free space in the volume group, you will first need to expand the volume group to complete the resize. Alternatively if you have multiple LVM partitions, you could shrink a different logical volume first to create space within the volume group.

Now that we have confirmed there is space free within the volume group, confirm the name of the logical volume you want to increase as well as how much space you plan on adding. The below lvdisplay command will show all logical volumes and their current size. It will also show the volume group that the logical volume is a member of, so ensure that the correct volume group has been checked for enough space with vgdisplay as previously mentioned to prevent trying to increase a logical volume that is inside some other volume group.

As shown in the example below, we are going to be working with the logical volume “var” which is in volume group “centos”, the volume group we saw in vgdisplay. In this example we only have just the one volume group, but you may have more so you need to check.

[root@CentOS7 ~]# lvdisplay
  --- Logical volume ---
  LV Path                /dev/centos/var
  LV Name                var
  VG Name                centos
  LV UUID                7PNgg2-ZmnG-a26g-zRoT-PRVM-RDc1-oq6J4M
  LV Write Access        read/write
  LV Creation host, time CentOS7, 2015-04-16 07:50:25 +1000
  LV Status              available
  # open                 0
  LV Size                5.00 GiB
  Current LE             1280
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:2

Now it’s time to expand the logical volume. In the below example we are using the -L flag to increase by a size specified (M for Megabytes, G for Gigabytes, T for Terabytes). You can alternatively remove the + to increase to the amount specified rather than by the amount specified.

lvextend -L+5G /dev/centos/var
  Rounding size to boundary between physical extents: 4.90 GiB
  Size of logical volume centos/var changed from 5.00 GiB (1280 extents) to 10.00 GiB (2560 extents).
  Logical volume var successfully resized

The above command will increase the logical volume /dev/centos/var by 5GB, currently it is already 5GB so this will increase it to a total of 10GB. You could achieve the same with “lvextend -L 10G /dev/centos/var” which will increase the logical volume to 10GB as well, as this is what was specified with no +. Alternatively if you instead want to just use all free space in the volume group rather than specifying a size to increase to, run “lvextend -l +100%FREE /dev/centos/var”.

We can run the below lvdisplay command shown below to check that the extend completed as expected.

[root@CentOS7 ~]# lvdisplay
  --- Logical volume ---
  LV Path                /dev/centos/var
  LV Name                var
  VG Name                centos
  LV UUID                7PNgg2-ZmnG-a26g-zRoT-PRVM-RDc1-oq6J4M
  LV Write Access        read/write
  LV Creation host, time CentOS7, 2015-04-16 07:50:25 +1000
  LV Status              available
  # open                 0
  LV Size                10.00 GiB
  Current LE             2560
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:2

Now that the logical volume has been extended, we can resize the file system. This will extend the file system so that it takes up the newly created space inside the logical volume. The command may differ depending on the type of file system you are using.

Use this for ext3/4 based file systems

resize2fs /dev/centos/var

Alternatively, use this for xfs based file systems

xfs_growfs /dev/centos/var

After the file system has been resized the space should be ready to use. If you run a ‘df’ command to view the disk space you should see that it’s been increased successfully.

[root@CentOS7 mnt]# df -h
Filesystem               Size  Used Avail Use% Mounted on
/dev/mapper/centos-root  9.8G  1.4G  8.5G  14% /
devtmpfs                 908M     0  908M   0% /dev
tmpfs                    914M     0  914M   0% /dev/shm
tmpfs                    914M  8.6M  905M   1% /run
tmpfs                    914M     0  914M   0% /sys/fs/cgroup
/dev/sda1                497M   96M  402M  20% /boot
/dev/mapper/centos-var    10G   33M   10G   1% /mnt

In this example I have run a ‘mount /dev/centos/var /mnt’ to mount the logical volume to /mnt, as shown above /mnt is correctly reporting a size of 10G.


We have now successfully expanded a file system and corresponding LVM logical volume without any down time. This was done by first expanding the logical volume, and then performing an on-line resize of the file system.

Leave a comment ?


  1. THANK YOU! The only site that explains resizing a LVM without adding another partition.

  2. Agreed! This was very helpful as well. I have a headless server running Fedora 25 that was granted 512 GB of space (what can I say, those base-2 numbers stick) and I couldn’t figure out why my root partition was only using 15 GB. Any other resources online mention creating a new partition which I didn’t even entertain as an option, since it’s an unacceptable solution

    Following your procedure I was able to expand the root partition by 300 GB and now I can start copying my 250 GB KVM image file again…. ;-)

    Others tutorials on others websites didn’t work!

    You saved me from format and reinstall all system. Thanks!

  4. Thank you so much for this informative article. I was stuck on a sunday afternoon with our sql server not being able to work due to space shortage on the hard disk drive.

  5. If the lvdisplay is showing the logical volume without path.

    How can I get the path so I can mount the volume? Thx

    • Can you provide the output that you get?

      You should be able to find it at /dev/vg_name/lv_name, so as long as you can get the vg/lv names from vgdisplay and lvdisplay it should be there by default.

  6. Appreciated! Especially the

    > you can perform it on a mounted volume without interruption.

    “little detail” :)

  7. …and it works like a charm on Fedora 26 too. Newly thanks.

  8. Thank you! This guide was exactly what I needed after adding some space in VMware to a Linux appliance and using a Gparted live CD to add the space to the partition.

  9. excellent repository.

  10. Well that was easy. Thanks for taking the complexity out of the problem.

  11. This works for CentOS 5.11. It was the fourth Internet recipe I tried. VERY much appreciated!

  12. Nice Explanation

  13. Super explanation, thanks. A little detail though, I think the resize command should be:

    resize2fs /dev/mapper/centos-var

  14. Ty it’s helped me out alot

  15. In CentOS 7 you can use the -r option to lvextend to resize the file system as well as resizing the volume size, instead of a separate call to resize2fs / xfs_growfs. Particulary useful if you want to shrink a partition as it does all the calculations for you. Doing it manually risks wrecking the file system if you make a mistake when shrinking.

    While I haven’t tested it it should also error out without making any changes if it can’t shrink the filesystem (e.g. too much data present in your ext4, and you can’t shrink an xfs filesystem).

  16. Tricky subject with amazing and pretty simple explanation.

  17. does it delete my data in the LV?

    • Which command are you referring to? The process as a whole, no it shouldn’t, if you you’re running something like lvremove on the other hand that then could be bad.

  18. It worked on a virtual Ubuntu 18.04 saving me a lot of headaches later! Thank you!

  19. Sumit srivastava

    excellent article.

    simple and crystal clear

  20. Great article – thanks – there was one typo I think where you said to
    “We can run the below lvdisplay command shown below to check that the extend completed as expected.”
    but the example in the box was vgdisplay

    “[root@CentOS7 ~]# vgdisplay”

  21. Thank you. After a lot of searching, your instructions were thorough and perfect for expanding our VM running an important climate research modeling tool, but running out of space!

  22. Your guide is simply EXCELLENT. Worked like a charm! Thank you very very much!

  23. I had to use:

    sudo xfs_growfs /var

    Instead of the xfs_growfs /dev/debian-vg/var
    cause it was giving me error:
    xfs_growfs: /dev/debian-vg/var is not a mounted XFS filesystem

    But thanks for this instruction. I’ll put this page to my bookmark

  24. I hate to be the only detractor, but I think the “How to increase an LVM partition” in this article’s title is inaccurate. What is described here is how to increase an LVM logical volume, not an LVM partition.

  25. Will these steps works for ONLINE File System(FS) extension even the FS is in inconsistent state.

    I’m extending the FS by increasing the existing device size and it fails at step resize2fs saying the permission denied. I’m using lvresize command instead of lvextend.

    Correction proposed for this issue is: unmount the MP, e2fsck and resize2fs but my use case does not allow unmount.

    Any help on extending the FS without un mounting the MP and correcting the FS and extending the FS.

  26. I cannot thank you enough. the amount of times i had to do this on production systems is…

  27. What does it mean if in vgdisplay and lvdisplay, the VG Size and LV Size are negative?!

  28. I successfully shrunk my `vgmint/root` volume using your related tutorial. There’s now 68G of free space according to `vgdisplay`:

    $ sudo vgdisplay
    --- Volume group ---
    VG Name vgmint
    System ID
    Format lvm2
    Metadata Areas 1
    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 1
    Act PV 1
    VG Size <930.28 GiB
    PE Size 4.00 MiB
    Total PE 238151
    Alloc PE / Size 220574 / <861.62 GiB
    Free PE / Size 17577 / 68.66 GiB

    But I run into errors trying to extend my second volume, `vgmint/swap`.

    $ sudo lvextend -L 48G /dev/vgmint/swap_1
    Size of logical volume vgmint/swap_1 changed from 976.00 MiB (244 extents) to 48.00 GiB (12288 extents).
    Logical volume vgmint/swap_1 successfully resized.

    $ sudo resize2fs /dev/vgmint/swap_1
    resize2fs 1.45.5 (07-Jan-2020)
    resize2fs: Bad magic number in super-block while trying to open /dev/vgmint/swap_1
    Couldn't find valid filesystem superblock.

    $ sudo e2fsck -fy /dev/vgmint/swap_1
    e2fsck 1.45.5 (07-Jan-2020)
    /dev/vgmint/swap_1 is mounted.
    e2fsck: Cannot continue, aborting.

    $ umount /dev/vgmint/swap_1
    umount: /dev/mapper/vgmint-swap_1: not mounted.

    Any ideas what’s going wrong here?

  29. A perfect guide, exactly what I needed. No fluff, right to the meat of the issue. Everything worked perfectly on RHEL 8.5.

    Much apprecaited!

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