How To Resize A Partition Of A Disk Define As A Physical Volume

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Hello,

I have a CentOS VM with only one disk on a Xenserver.

The disk has 2 partitions:

/dev/xvda1 -> /boot
/dev/xvda2 -> a physical volume for LVM

I added 5GB to this disk via Xencenter to extend /dev/xvda2. Usually I
just have to do “pvresize /dev/xvda” to have the additional space added to the disk. But for some reason it does not work for this disk.

[root ~]# pvresize /dev/xvda
Failed to find physical volume “/dev/xvda”.
0 physical volume(s) resized / 0 physical volume(s) not resized

[root ~]# pvresize /dev/xvda2
Physical volume “/dev/xvda2” changed
1 physical volume(s) resized / 0 physical volume(s) not resized

Does someone have seen this problem before or could have an idea of the problem?

Thanks, Bernard

9 thoughts on - How To Resize A Partition Of A Disk Define As A Physical Volume

  • Looks like xvda2 was resized. You should now have an added
    5GB worth of unallocated extents in the vg

  • I should have added the output of pvs:

    [root ~]# pvs
    PV VG Fmt Attr PSize PFree
    /dev/xvda2 cl_vm731611 lvm2 a– 9.00g 0

    PFree still show 0. It should show 5g.

    Also:
    [root ~]# pvdisplay /dev/xvda2
    — Physical volume –

  • It is preferrable to create PV on the whole disk also to manage these kind of situations. In case I have to manage with partitions, the must is that you can do it only if it is the last partition, and you are ok. Normally I use fidsk and I first delete the last partition and then without exiting the utility I create again it using the same starting point and the new larger end. For this, take care of using option to show sectors and not cylinders (“u”
    switches between the two options) and print your partition layout (“p”
    comamnd), so that you can set exactly the same starting point of the new xvda2 partition otherwise you will have destroyed it and LVM layer would not be able to identify it (also the type if now it is 8e for Linux LVM). Eventually you will have to run also the command

    partprobe /dev/xvda

    to align os with new partition layout

    Take care and read well (also on other sources on internet in case). Also backup your partiion layout before making changes with

    sfdisk -d /dev/xvda > part_table.before

    and compare with what you have after.

    HIH, Gianluca

  • I usually use the whole disk a PV but this disk has the /boot partition which cannot be LVM.

    I decided to simply use the third partition as another PV and extended the VG.

    Thanks,

  • If you don’t trust yourself to do it right, just create a new partition on the disk, pvcreate it, add it to the existing volume group.

    jh

  • Bernard Fay wrote:

    Dunno ’bout gparted, but parted->t, if you ask for help, it lists types, and linux lvm is one type. A quick search tells me partition type e1.

    mark

  • Hello,

    I have a CentOS VM with only one disk on a Xenserver.

    The disk has 2 partitions:

    /dev/xvda1 -> /boot
    /dev/xvda2 -> a physical volume for LVM

    I added 5GB to this disk via Xencenter to extend /dev/xvda2. Usually I
    just have to do “pvresize /dev/xvda” to have the additional space added to the disk. But for some reason it does not work for this disk.

    [root ~]# pvresize /dev/xvda
    Failed to find physical volume “/dev/xvda”.
    0 physical volume(s) resized / 0 physical volume(s) not resized

    K

    Xvda does not seem to be read as an LVM volume. Xvda2 is handled by lvm so this can be resized. However xvda is just the harddrive itself. From what I
    have learned using lvm briefly, you can only resize lvm volumes or partitions created using lvm.

    [root ~]# pvresize /dev/xvda2
    Physical volume “/dev/xvda2” changed
    1 physical volume(s) resized / 0 physical volume(s) not resized

    Does someone have seen this problem before or could have an idea of the problem?

    Thanks, Bernard