@diego said:

However, from a system design perspective, I was wondering if it would be better to:

keep the system disk small (OS + Cloudron core)
attach a separate disk dedicated to mail storage

Yes you can do that.
I also do that with my private Hetzner server so I can scale up the CPU/RAM and have the storage seperate.

@diego said:

Will the Cloudron backup system still include it normally?

Yes.
If you move e.g.: /home/yellowtent/boxdata/mail to /mnt/sdd1 and create a symlink so /home/yellowtent/boxdata/mail => /mnt/sdd1 this still works.

What you can always to is creating a small Cloudron server to test and tinker as much as you like.
This way you get a better feeling for everything without risking any damage to production.

Thanks for the response.

My question is more about architecture and best practices for running Cloudron as a more serious mail server setup.

Until now my usage was mostly hobby-level, with small mailboxes. Now I need to host around 60 accounts totaling ~1TB, so I'm trying to design the setup properly before deploying it.

What I'm trying to understand is mainly:

1. Storage layout

I understand I could simply expand the primary disk of the VM. That is straightforward in Proxmox.

However, from a system design perspective, I was wondering if it would be better to:

• keep the system disk small (OS + Cloudron core)
• attach a separate disk dedicated to mail storage

For example mounting something like:

/home/yellowtent/boxdata/mail

on a dedicated volume.

The idea behind this would be:

• better separation between system and mail data
• easier capacity management
• possibility of using a filesystem with compression (e.g. zstd) to maximize storage efficiency
• simpler disk replacement or migration in the future

But at the same time I don't want to diverge from the recommended Cloudron layout, because I would like to keep the installation as "standard" as possible in case I ever need support.

So the main question is:
Is expanding the main disk considered the recommended production setup for Cloudron mail servers?

Or is using a dedicated volume for mail storage also a common and supported approach?

2. Backups

Regarding backups, my doubt is specifically about data located on a secondary disk.

If I move /home/yellowtent/boxdata/mail to another mounted disk:

• Will the Cloudron backup system still include it normally?
• Or are there caveats when the data directory is located on another filesystem / mount point?

I'm not trying to customize Cloudron unnecessarily — I'm mainly trying to understand what a good production storage design looks like when Cloudron is used as a mail server with ~1TB of mail data.

Any recommendations or real-world setups from other users would also be very helpful.

Best regards,
Diego

@diego said:

What backup strategy should I use?
Does the PRO license already cover this scenario? Or should I use the Business license?

The Cloudron backup functionality does not require a subscription.
I am also not sure what you are asking for.
Please elaborate further, so we can give precise feedback.

@diego said:

Using it installed as a guest in a Proxmox environment.

If it is a KVM in Proxmox, why not simply enlarge the already existing disk?

If you want to use an attached disk as the storage, you can view this documentation section here:
https://docs.cloudron.io/server#default-data-directory

Note, this doc only writes about appsdata and boxdata.
You could also move the whole home /home/yellowtent to the external disk.
Or if you'd like to only move the mail data to the external disk, that would be /home/yellowtent/boxdata/mail/.