Increasing LVM Partition Size in Proxmox Guest

This guide outlines the steps to increase the size of an LVM (Logical Volume Management) partition on a Proxmox guest machine, assuming it has free space within the existing Volume Group.

Prerequisites:

• You have a Proxmox guest VM running.
• You have SSH access to the guest VM.
• There is free space within the existing Volume Group.

Steps:

1. Check Disk and Volume Group Information:

• Use dmesg | grep sda (replace sda with your disk if different) to check if the kernel has detected the increased disk size. You should see a message indicating a capacity change.

[    0.959629] sd 2:0:0:0: [sda] 461373440 512-byte logical blocks: (236 GB/220 GiB)
[    0.960052] sd 2:0:0:0: [sda] Write Protect is off
[    0.960416] sd 2:0:0:0: [sda] Mode Sense: 63 00 00 08
[    0.960452] sd 2:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[    0.964725]  sda: sda1 sda2 sda3
[    0.965509] sd 2:0:0:0: [sda] Attached SCSI disk
[    3.451244] EXT4-fs (sda2): mounted filesystem with ordered data mode. Opts: (null). Quota mode: none.
[  203.903185] sd 2:0:0:0: [sda] 463470592 512-byte logical blocks: (237 GB/221 GiB)
[  203.903254] sda: detected capacity change from 461373440 to 463470592

• List partitions: Use fdisk -l /dev/sda to display the partition table of your disk (/dev/sda in this case). Identify the partition that holds your LVM Physical Volume (usually the largest).

/dev/sda1     2048      4095      2048    1M BIOS boot
/dev/sda2     4096   4198399   4194304    2G Linux filesystem
/dev/sda3  4198400 356515806 352317407  168G Linux filesystem

• Display Volume Group information: Use vgs to view the Volume Groups and their free space. Note the name of your Volume Group (e.g., ubuntu-vg).

  VG        #PV #LV #SN Attr   VSize    VFree
  ubuntu-vg   1   1   0 wz--n- <168.00g    0

2. Extend the Partition:

• Usefdisk to extend the partition that holds your LVM Physical Volume:
• Run sudo fdisk /dev/sda (replace sda with your disk).
• Type p and press Enter to list partitions. Note the starting sector of the LVM partition (e.g., /dev/sda3).
• Type d and press Enter to delete the LVM partition.
• Type n and press Enter to create a new partition.
• Choose partition type p for primary.
• Enter the same partition number as the one you deleted.
• Set the first sector to the starting sector you noted earlier.
• Set the last sector to use all available space (press enter).
• Do you want to remove the signature? [Y]es/[N]o: n (if you select ‘y’, it will corrupt your filesystem)
• Type w and press enter to write the changes.

3. Resize the Physical Volume:

• Use pvresizeExecute the following command to add all available free space to your Logical Volume

sudo pvresize /dev/sda3

• (Replace /dev/sda3 with the actual partition if different.)

4. Extend the Logical Volume

• Use lvextendExecute the following command to resize the filesystem to match the new Logical Volume size:

sudo lvextend -l +100%FREE /dev/ubuntu-vg/ubuntu-lv

Again, replace /dev/ubuntu-vg/ubuntu-lv with the path to your Logical Volume.)

5. Resize the Filesystem:

• Use resize2fs to resize the filesystem:

sudo resize2fs /dev/mapper/ubuntu--vg-ubuntu--lv

(Replace /dev/mapper/ubuntu--vg-ubuntu--lv with the path to your Logical Volume.)

6. Verify the Changes:

• Run df -h to confirm that the size of your partition has increased.
• Backups: Create a backup of your VM before making any disk changes.
• Online Resizing: resize2fs usually resizes the filesystem online. However, minimize disk activity during the process.

This guide provides a framework. Refer to official documentation for the most accurate information.