[SOLVED] swapoff - Is it possible to reclaim pve-swap space for pve-root?

[thisisbenwoo]

Hello all,

I run all my nodes with SSDs or NVMe drives. I don't like using swap with these devices. Additionally, most of my nodes are read-only nodes. I've measured that my R/W ratio is >90%/10%. I know that many of you might want to challenge my decision on doing this, and I am happy to debate this in another thread.

But since that's the decision I am taking, what I'd like to understand is if it is possible now that my swap volume (pve-swap) is now 0, to reclaim that space and allocate it to the pve-root volume.

lsblk gives the following output:
NAME                         MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
nvme0n1                      259:0    0   477G  0 disk
├─nvme0n1p1                  259:1    0  1007K  0 part
├─nvme0n1p2                  259:2    0   512M  0 part /boot/efi
└─nvme0n1p3                  259:3    0 476.4G  0 part
  ├─pve-swap                 253:0    0     8G  0 lvm
  ├─pve-root                 253:1    0    96G  0 lvm  /
  ├─pve-data_tmeta           253:2    0   3.6G  0 lvm
  │ └─pve-data-tpool         253:4    0 349.3G  0 lvm
  │   ├─pve-data             253:5    0 349.3G  0 lvm
  │   ├─pve-vm--100--disk--0 253:6    0     4M  0 lvm
  │   ├─pve-vm--100--disk--1 253:7    0    32G  0 lvm
  │   ├─pve-vm--101--disk--0 253:8    0     4M  0 lvm
  │   └─pve-vm--101--disk--1 253:9    0    48G  0 lvm
  └─pve-data_tdata           253:3    0 349.3G  0 lvm
    └─pve-data-tpool         253:4    0 349.3G  0 lvm
      ├─pve-data             253:5    0 349.3G  0 lvm
      ├─pve-vm--100--disk--0 253:6    0     4M  0 lvm
      ├─pve-vm--100--disk--1 253:7    0    32G  0 lvm
      ├─pve-vm--101--disk--0 253:8    0     4M  0 lvm
      └─pve-vm--101--disk--1 253:9    0    48G  0 lvm

Is it possible to reclaim pve-swap 8G and allocate it to pve-root??
Thanks in advance!

 

[Lorenz.S]

Yes, this is theoretically possible. You would have to swapoff -a, remove the swap entry in /etc/fstab, delete the lvm swap LV (logical volume) and extend the root LV and its FS.

There are plenty of tutorials online on how to such operations on LVM environments (e.g. Step 4+5 of [0]) - ask your favorite search engine

[0] https://creativeandcritical.net/hel...lete-swap-volume-extend-root-volume-fedora-20

 

[thisisbenwoo]

Thanks Lorenz. This is a great solution. Thanks! Marking solved.