Re: is it possible to use LVM AFTER system installation?

Roger Heflin
2026-02-21T18:35:24Z

That seems pretty close to right. Step 1 I would label the
partition as LVM, not that it really matters since the labels seem to
not be actively used in Linux) I did not look at every last step in
detail, but that is pretty close to what should work if executed
correctly.

On step 7 you probably need to execute it with the primary user logged
out and from a non-gui login(or a root login assuming root's home is
/root and not in /home) to get a clean copy.

You may need to make sure your initramfs has lvm built into it, it may
not really matter for home given it can mount much later than say /
(if using lvm for /).

On Sat, Feb 21, 2026 at 11:58 AM Frédéric Baldit
<frederic.baldit@free.fr> wrote:
>
>
> Hi everybody,
>
> I'm a debian 12 user, running it on a system which was initially
> installed without LVM (on a thinkpad laptop)n with classical netinst. My
> system is totally installed on a unique nvme disk, with distinct
> partitions, among which a /home partition for all my personal data.
>
> I recently installed a second nvme disk (512G capacity). I would like
> to extend my /home ext4 partition (which is now exclusively on
> /dev/nvme0n1p6, 436G) so that I can keep my old data but have
> the possibility to split /home on the initial disk and the second
> recently added disk.
>
> This seems to be possible with LVM but only when decided at the
> beginning of the installation. Right or wrong?
>
> Or would it possible to:
>
> 0) install lvm2 on my system
> 1) create a new ext4 partition (512G size) on the new nvme disk (using
> all available space, 512G, on it)
> 2) create a new PV with this partition
> 3) create a new VG containing this unique PV
> 4) create a new LV on this VG
> 5) format this LV as an ext4 filesystem with mkfs.ext4
> 6) mount this LV on a new system directory, say /home1
> 7) migrate all the data on my old /home to the new /home1
> 8) modify the VG created before in order to add to it the
> /dev/nvme0n1p6 PV
> 9) resize the LV so that it can use the new PV added
> 10) rename /home1 to /home
>
> Is this globally correct??? Step 7 if crucial, as I really don't want
> any loss or corruption of personal data during the transfer.
>
> Thank's in advance for any help to my two questions,
>
> F. Baldit.
>
>
>
> --
> Frédéric Baldit
>