Problem Overview

• A filesystem is running out of space, but the volume group already has unallocated free space.

• Instead of attaching a new disk or resizing partitions, the goal is to extend the logical volume and grow the filesystem using the available VG space while the system remains online.

Prerequisites

Before starting, make sure the following conditions are met:

• The system is already using LVM for storage management

• The volume group contains unused free space

• Backup of the LV for which the storage is increased

Solution

• Identify the logical volume that needs more space and confirm its mount point to ensure the correct LV is being modified.

  • [root@pythonlinuxhub ~]# lsblk
    NAME             MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS
    sda                8:0    0   20G  0 disk
    ├─sda1             8:1    0    1G  0 part /boot
    └─sda2             8:2    0   19G  0 part
      ├─rhel_10-root 253:0    0   17G  0 lvm  /
      └─rhel_10-swap 253:1    0    2G  0 lvm  [SWAP]
    sdb                8:16   0    6G  0 disk
    ├─sdb1             8:17   0    1G  0 part
    │ └─rhel_10-home 253:2    0 1020M  0 lvm  /home
    └─sdb2             8:18   0    2G  0 part
      └─rhel_10-data 253:3    0    1G  0 lvm  /data
    sr0               11:0    1 1024M  0 rom
    [root@pythonlinuxhub ~]# df -h /data
    Filesystem                Size  Used Avail Use% Mounted on
    /dev/mapper/rhel_10-data  960M   39M  922M   5% /data

• Verify that the volume group has sufficient unused free space available for allocation.

  • [root@pythonlinuxhub ~]# pvs
      PV         VG      Fmt  Attr PSize    PFree
      /dev/sda2  rhel_10 lvm2 a--   <19.00g       0
      /dev/sdb1  rhel_10 lvm2 a--  1020.00m       0
      /dev/sdb2  rhel_10 lvm2 a--    <2.00g 1020.00m
    [root@pythonlinuxhub ~]# vgs
      VG      #PV #LV #SN Attr   VSize   VFree
      rhel_10   3   4   0 wz--n- <21.99g 1020.00m
    [root@pythonlinuxhub ~]# lvs
      LV   VG      Attr       LSize    Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
      data rhel_10 -wi-ao----    1.00g
      home rhel_10 -wi-ao---- 1020.00m
      root rhel_10 -wi-ao----  <17.00g
      swap rhel_10 -wi-ao----    2.00g

• Extend the logical volume using the selected portion of free space from the volume group.

  • [root@pythonlinuxhub ~]# lvextend -l +50%FREE /dev/rhel_10/data
      Size of logical volume rhel_10/data changed from 1.00 GiB (256 extents) to 1.50 GiB (384 extents).
      Logical volume rhel_10/data successfully resized.

• Grow the filesystem, so it can utilize the newly extended logical volume without downtime.

  • [root@pythonlinuxhub ~]# xfs_growfs /data
    meta-data=/dev/mapper/rhel_10-data isize=512    agcount=4, agsize=65536 blks
             =                       sectsz=512   attr=2, projid32bit=1
             =                       crc=1        finobt=1, sparse=1, rmapbt=0
             =                       reflink=1    bigtime=1 inobtcount=1 nrext64=0
    data     =                       bsize=4096   blocks=262144, imaxpct=25
             =                       sunit=0      swidth=0 blks
    naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
    log      =internal log           bsize=4096   blocks=16384, version=2
             =                       sectsz=512   sunit=0 blks, lazy-count=1
    realtime =none                   extsz=4096   blocks=0, rtextents=0
    data blocks changed from 262144 to 393216

• Validate the change by confirming that the logical volume and filesystem now reflect the increased capacity.

  • [root@pythonlinuxhub ~]# df -h /data
    Filesystem                Size  Used Avail Use% Mounted on
    /dev/mapper/rhel_10-data  1.5G   43M  1.4G   3% /data

    [root@pythonlinuxhub ~]# pvs
      PV         VG      Fmt  Attr PSize    PFree
      /dev/sda2  rhel_10 lvm2 a--   <19.00g      0
      /dev/sdb1  rhel_10 lvm2 a--  1020.00m      0
      /dev/sdb2  rhel_10 lvm2 a--    <2.00g 508.00m
    [root@pythonlinuxhub ~]# vgs
      VG      #PV #LV #SN Attr   VSize   VFree
      rhel_10   3   4   0 wz--n- <21.99g 508.00m
    [root@pythonlinuxhub ~]# lvs
      LV   VG      Attr       LSize    Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
      data rhel_10 -wi-ao----    1.50g
      home rhel_10 -wi-ao---- 1020.00m
      root rhel_10 -wi-ao----  <17.00g
      swap rhel_10 -wi-ao----    2.00g

• lvextend -L 1.5G /dev/rhel_10/data
  # Resizes the logical volume to an exact size of 1.5 GB

• lvextend -L +500M /dev/rhel_10/data
  # Adds 500 MB to the current size of the logical volume

• lvextend -l +50%FREE /dev/rhel_10/data
  # Extends the logical volume using 50% of the free space available in the volume group