How to replace a disk

I have OMV 6 on a Raspberry Pi 4 with 2 USB HDD formated Ext4, both just normal mounted (no RAID, LVM,...)

I have different users, some shares on each disk and gave access to the shares for services (e.g. rsanpshot, SFTP, rsync task, rsync module) and users.

I am wondering whats the recomended way to replace one of the disks by a newer one.

e.g. in case I want to replace a 2 TB disk by a 4 TB disk.

On OMV 5 this should have been easy. Just copy the whole contents (ensure UID, GID are the same), label the disk exactly same as the smaler one, shutdown, unplug 2 TB disk, plug 4 TB disk.

But on OMV 6 disks are identified by UUID. How can I tell OMV that the new disk is the replacement for the smaler one?

Where to assign the new disk so that the shares with all access rights,... are mapped to the new disk?

Or do I have to change the UUID of the new disk to be exactly the same as the old one?

So whats best practice for this quit common usecase?

Thanx in advance!

BR - Jochen

P.S.: Background/motivation/reason for asking:

1. I have another sytem, same setup as above, and I rsync one of the disks on my working system to the other system; rsync is is donw with "-azgo -H --delete --numeric-ids " so that the shares on the remote disk is a exact "clone" of the local one).

So if the local one fails, I ll get the one from the remote location, plug it and should be able to work normal as if nothing had happened.

2. One of the disks migth run out of space. I ll get a large one cp/rsync the contents of the working disk, undplug it, plug the larger one, work normal as if nothing had happened.

BR - Jochen

Thanx for exact explanations.

Seems to be a good, straight forward practice if the old/smal disk is stil ok and running and more disk space is needed.

Also thanx for the hint using screen in the ssh session if doing such time consuming tasks remotely.

But whats the reccomended way if the work disk just failed and a backup restore to a new disk must be done.

How restoreing form a previous local rsnapshot or remote rsync to an new empty disk is quit clear for me.

But then whats the best practice to get this disk up and running in OMV 6, so that shares, users, services (accessing some shares) are working?!?

Is it just prevent the file system structure (restoring rsnapshot / rsync backup) and setting same UUID the failed disk had to the new one?

If so where is a good place to lookup the old UUID if the old disk already failed totally (cant be accessed, mounted,...)?

BR - Jochen