Extending a logical volume and filesystem online in RHEL after disk resize

Environment

• Red Hat Enterprise Linux 10
• Red Hat Enterprise Linux 9
• Red Hat Enterprise Linux 8
• Red Hat Enterprise Linux 7
• Red Hat Enterprise Linux 6
• Red Hat Enterprise Linux 5
• Logical Volume Manager (LVM) 2

Issue

• How do I make the extended size visible in PV and VG after extending the size of the existing disk?
• When the existing vmdk disk is extended in ESX, PV and VG does not detect the new size.
• How can I increase the size of my physical volume without rebooting?

Resolution

Warning: Red Hat recommends that all critical data be backed up and verified before making any changes to the underlying storage, as an unforeseen problem might occur.

1. Extend the disk in question (/dev/sdx) from the storage side, then rescan the device:

# echo 1 > /sys/block/sdx/device/rescan 

Verify the new size:

# lsblk

2. Determine how the disk is used, check whether the disk is partitioned:

# lsblk

Proceed according to one of the following scenarios:

Scenario A: Disk is not partitioned (PV directly on /dev/sdx)
No partition changes are required. Resize the physical volume:

# pvresize /dev/sdx

Scenario B: Disk has a single partition that will be extended
Extend the existing partition to use all available space:

# parted /dev/sdx resizepart 1 100%

Resize the physical volume on the partition:

# pvresize /dev/sdx1

Scenario C: Disk has existing partitions, and a new partition will be created
Create a new partition using the free space:

# parted /dev/sdx u s p (to check the current configuration)
# parted /dev/sdx

Create a PV on the new partition:

# pvcreate /dev/sdx2 

Extend the VG:

# vgextend vgname /dev/sdx2

3. Extend the logical volume using the newly available free space. The following example extends the logical volume to use all new free space in the volume group:

# lvextend -l +100%FREE /dev/vgname/lvname

4. Resize the filesystem:

# resize2fs /dev/mapper/vgname-lvname (for ext4)
# xfs_growfs /dev/mapper/vgname-lvname (for xfs)

For further assistance, please open a Red Hat support This content is not included.case.

Notes:

• If the filesystem is GFS2, refer to: How do I grow a GFS2 file-system on RHEL?.
• Once an XFS filesystem is extended, it cannot be reduced: How to reduce XFS file system
• The lvextend command supports resizing the filesystem automatically using the -r option. From the man page:

-r, --resizefs
          Resize underlying filesystem together with the logical volume using

• If you are adding a new disk (PV) rather than extending the existing disk to extend the logical volume, please refer to the corresponding solution: Extending a logical volume and filesystem online in RHEL using a new disk.

Diagnostic Steps

• See the following man pages and manuals:
  • man pvcreate 8
  • man vgextend 8
  • man lvextend 8
  • man resize2fs 8
  • man xfs_growfs 8
  • RHEL5: Logical Volume Manager Administration LVM Administrator's Guide
  • RHEL6: Logical Volume Manager Administration LVM Administrator's Guide
  • RHEL7: Logical Volume Manager Administration LVM Administrator's Guide
  • RHEL8: Configuring and managing logical volumes
  • RHEL9: Configuring and managing logical volumes

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