Our root partition is filling up and we want to increase its size on LVM.
General disclaimer applies, no liability will be accepted for any loss or damage, use at your own risk and do frequent backups!
Software used in this article:
- Oracle Linux 6.6
- lvm2, e2fsck, resize2fs
Before We Begin
We are using Oracle Linux 6.6 on VirtualBox in this example (VirtualBox is not covered here).
Disk partition table looks like this:
# fdisk -l | grep sd Disk /dev/sda: 12.9 GB, 12884901888 bytes /dev/sda1 * 1 52 409600 83 Linux /dev/sda2 52 1567 12172288 8e Linux LVM
We have a single 13GB disk and two partitions on it.
Root partition usage can be seen below. It’s got around 600MB of free space.
# df -h / Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg_oracle-lv_root 7.0G 6.0G 631M 91% /
Disks scans for physical volumes:
# pvscan PV /dev/sda2 VG vg_oracle lvm2 [11.61 GiB / 0 free] Total: 1 [11.61 GiB] / in use: 1 [11.61 GiB] / in no VG: 0 
# pvs PV VG Fmt Attr PSize PFree /dev/sda2 vg_oracle lvm2 a-- 11.61g 0
Volume groups and logical volumes are as below:
# vgs VG #PV #LV #SN Attr VSize VFree vg_oracle 1 4 0 wz--n- 11.61g 0
# lvs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert lv_home vg_oracle -wi-ao---- 1.95g lv_root vg_oracle -wi-ao---- 7.21g lv_swap vg_oracle -wi-ao---- 500.00m lv_var vg_oracle -wi-ao---- 1.95g
Extend root LVM
Extend the disk on VirtualBox and check the disk partition table:
# fdisk -l | grep sd Disk /dev/sda: 32.2 GB, 32212254720 bytes /dev/sda1 * 1 52 409600 83 Linux /dev/sda2 52 1567 12172288 8e Linux LVM
It’s now got 32GB of disk space.
Modify disk partition table so that the second partition (the LVM one) is extended. Be very careful here.
# fdisk /dev/sda >> d (delete) >> 2 >> n (create a new one) >> p >> 2 >> [enter] make sure the first cylinder matches the one you deleted before (i.e. 52) >> [enter] last cylinder should be default to use all space available >> p >> t (change filesystem type to LVM) >> 2 >> 8e >> p >> w (save changes)
Partitions information will be re-read after reboot:
Alternatively to system reboot, you can read disk (see https://access.redhat.com/solutions/57542) and try to add a new partition to the system (use at your own risk):
# partx -v -a /dev/sda
After reboot, resize
/dev/sda2 physical volume:
# pvresize /dev/sda2 Physical volume "/dev/sda2" changed 1 physical volume(s) resized / 0 physical volume(s) not resized
Check physical volume and volume group information:
# pvs PV VG Fmt Attr PSize PFree /dev/sda2 vg_oracle lvm2 a-- 29.61g 18.00g
# vgs VG #PV #LV #SN Attr VSize VFree vg_oracle 1 4 0 wz--n- 29.61g 18.00g
Extend the logical root volume by 10GB:
# lvextend --size +10GB /dev/mapper/vg_oracle-lv_root Size of logical volume vg_oracle/lv_root changed from 7.21 GiB (1846 extents) to 17.21 GiB (4406 extents). Logical volume lv_root successfully resized
You should really check the filesystem at this point, however, the results printed by e2fsck are not valid if the filesystem is mounted:
# e2fsck -n /dev/mapper/vg_oracle-lv_root
Resize an ext4 filesystem on the root volume:
# resize2fs /dev/mapper/vg_oracle-lv_root resize2fs 1.43-WIP (20-Jun-2013) Filesystem at /dev/mapper/vg_oracle-lv_root is mounted on /; on-line resizing required old_desc_blocks = 1, new_desc_blocks = 2 The filesystem on /dev/mapper/vg_oracle-lv_root is now 4511744 blocks long.
Check root partition usage:
# df -h / Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg_oracle-lv_root 17G 6.0G 11G 38% /