Resizing (or removing) Local-LVM

When installing Proxmox to an ext4 volume, the installer assigns the majority of your boot disk to "Local-LVM". This may not be desirable if you plan on using a secondary disk for VM storage, and would like to store more ISO images and backups in the root volume (known in Proxmox as "Local").

First, run lvdisplay (Logical Volume display) as root to check the current layout:

root@pve:~# lvdisplay
  --- Logical volume ---
  LV Path                /dev/pve/swap
  LV Name                swap
  VG Name                pve
  LV UUID                DkDV6A-7iqo-70kO-i9Gx-d9qo-XaCu-VUCAYb
  LV Write Access        read/write
  LV Creation host, time proxmox, 2021-03-13 22:40:36 +0000
  LV Status              available
  # open                 2
  LV Size                8.00 GiB
  Current LE             2048
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:0
   
  --- Logical volume ---
  LV Path                /dev/pve/root
  LV Name                root
  VG Name                pve
  LV UUID                pqcv3c-Csis-fBqQ-ARkb-3xzo-7xau-DaRzxT
  LV Write Access        read/write
  LV Creation host, time proxmox, 2021-03-13 22:40:37 +0000
  LV Status              available
  # open                 1
  LV Size                58.00 GiB
  Current LE             14848
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:1
   
  --- Logical volume ---
  LV Name                data
  VG Name                pve
  LV UUID                tyoWtm-fyEr-PqRg-5Sn2-dcTq-tE69-qKHprl
  LV Write Access        read/write
  LV Creation host, time proxmox, 2021-03-13 22:40:37 +0000
  LV Pool metadata       data_tmeta
  LV Pool data           data_tdata
  LV Status              available
  # open                 0
  LV Size                <147.38 GiB
  Allocated pool data    0.00%
  Allocated metadata     1.08%
  Current LE             37728
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:4

Based on the above output, we see that pve-data (local-lvm in the Proxmox GUI) is almost 3 times the size of the root volume. To resize this, you will first need to remove it. This will delete all contents of local-lvm, so please back up any virtual machines and remove them first so you don't lose anything!

root@pve:~# lvremove /dev/pve/data -y
  Logical volume "data" successfully removed

Optional - If you still require a local-lvm partition (but want to give it less space) you can recreate it with the following command (in this example, 40G is specified to give it 40 Gibibytes).

root@pve:~# lvcreate -L 40G -n data pve -T
  Thin pool volume with chunk size 64.00 KiB can address at most 15.81 TiB of data.
  Logical volume "data" created.

The logical volume for root can then be resized to give it all available free space:

root@pve:~# lvresize -l +100%FREE /dev/pve/root
  Size of logical volume pve/root changed from 58.00 GiB (14848 extents) to 224.38 GiB (57442 extents).
  Logical volume pve/root successfully resized.

Once the logical volume has been resized, the ext4 partition must also be resized using resize2fs:

root@pve:~# resize2fs /dev/mapper/pve-root
resize2fs 1.44.5 (15-Dec-2018)
Filesystem at /dev/mapper/pve-root is mounted on /; on-line resizing required
old_desc_blocks = 8, new_desc_blocks = 29
The filesystem on /dev/mapper/pve-root is now 58820608 (4k) blocks long.

Once resized, run lvdisplay again to verify the changes have taken effect.

root@pve:~# lvdisplay 
  --- Logical volume ---
  LV Path                /dev/pve/swap
  LV Name                swap
  VG Name                pve
  LV UUID                DkDV6A-7iqo-70kO-i9Gx-d9qo-XaCu-VUCAYb
  LV Write Access        read/write
  LV Creation host, time proxmox, 2021-03-13 22:40:36 +0000
  LV Status              available
  # open                 2
  LV Size                8.00 GiB
  Current LE             2048
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:0
   
  --- Logical volume ---
  LV Path                /dev/pve/root
  LV Name                root
  VG Name                pve
  LV UUID                pqcv3c-Csis-fBqQ-ARkb-3xzo-7xau-DaRzxT
  LV Write Access        read/write
  LV Creation host, time proxmox, 2021-03-13 22:40:37 +0000
  LV Status              available
  # open                 1
  LV Size                224.38 GiB
  Current LE             57442
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:1

Then, log into the Proxmox GUI and go to Datacenter > Storage and remove the local-lvm entry: