Mounting a second partition

Hi, im new to Nextcloud. I am running Nextcloud 11.0.2 on CentOS 6. I was hoping if someone could help me or at least direct me to some documentation that explains how to configure Nextcloud to use second partition. Because for the life of me, I cant find any information about how this is done. Currently I have 2 partitions that look like this.

Disk /dev/vda: 26.8 GB, 26843545600 bytes - primary, already used for nextcloud
Disk /dev/vdb: 53.7 GB, 53687091200 bytes - secondary that needs to be configured to work with nextcloud

You can just move the data-folder on your second partition /dev/vdb. This is very easy, the first partition is then used for the system and database.

You can just use it as external storage for Nextcloud, so you have an additional folder in your account (you have to do it with a group folder as admin user, or for each user individually).

If you really want to merge both disks that it appears to be like one large disk, you can use logical volume management: