[PROXMOX CLUSTER] Shared disk for VM

[avaaru]

Hi everyone,

I have a Proxmox cluster with 2 nodes. Node 2 has a 12TB disk (currently empty) that I’d like to use as shared storage between both nodes. My goal is:

• Store VMs on this shared disk
• Be able to migrate VMs between nodes without copying the disks
• Be able to take snapshots of those VMs

I’ve seen that this could be done via NFS, but from what I understand, snapshots are not supported on NFS storage in Proxmox.

Is there any viable solution that:

• Allows sharing this disk between nodes?
• Supports native snapshots?

I'm a bit lost and I don't see what the best way is.

Thank you

 

[floh8]

When u use qcow2 files via NFS u get snapshot support.

 

[bbgeek17]

Running a VM as NFS server is your best option. Keep in mind that the host that owns the disks is your single point of failure in that case.

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Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

 

[avaaru]

When u use qcow2 files via NFS u get snapshot support.

So I simply format the 12TB disk in ext4 and share it via NFS, and this will allow me to create virtual machines with qcow2?

 

[bbgeek17]

So I simply format the 12TB disk in ext4 and share it via NFS, and this will allow me to create virtual machines with qcow2?

Yes, at a high level thats correct. Whether it is wise to create a 12TB qcow on ext4 formatted consumer disk as another question. It will work for a homelab.

Cheers

PS hopefully its not USB connected...

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Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

 

[avaaru]

Yes, at a high level thats correct. Whether it is wise to create a 12TB qcow on ext4 formatted consumer disk as another question. It will work for a homelab.

Cheers

PS hopefully its not USB connected...

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Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

In this case, it's for two small dedicated servers at OVH that we have at the company. That's why I'm looking for the best way to configure a shared disk for creating the VMs, without losing VM functionality and without causing errors.
The disk is connected inside the server, not via USB.

 

[bbgeek17]

As long as this setup matches company's risk tolerance - you are ok.

---

Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

 

[avaaru]

As long as this setup matches company's risk tolerance - you are ok.

---

Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

I understand that CT containers would also work?

 

[bbgeek17]

I understand that CT containers would also work?

As NFS server? Sure.

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Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

 

[floh8]

container do have only snapshot support on btrfs, zfs or lvm thin not NFS

 

[avaaru]

Is there any way to share an LVM-THIN volume over a network? Would ZFS be the only way to have a shared volume that allows me to create both CTs and VMs?

 

[floh8]

Maybe u start reading the docu first and ask then after details

 

[avaaru]

Are you referring to the following table? I had read it, but it doesn't match the information I'm reading online or that you're giving me. You're saying that NFS can take snapshots, but the table says it can't. That's why I'm asking, because I see different opinions and it's not clear to me which one is correct.

 

[avaaru]

The guide indicates that a shared LVM is also compatible, is that correct?

 

[Onslow]

You're saying that NFS can take snapshots, but the table says it can't.

No and yes. That table says "no" but it has the remark numbered "2":

2: "On file based storages, snapshots are possible with the qcow2 format."

 

[Johannes S]

Adding to onslow: qcow2 is a format for vm discs images on file-based storages like directory, nfs, cifs etc. Since this format is restricted to vm images you can achieve snapshots of vms stored on nfs with them but not on lxcs. You could still create backups of the lxcs though, combined with change-detection-mode set to meta-data in the backup settings and ProxmoxBackupServer you can achieve a similiar functionality like with snapshots (create a backup before some change/update, do the change. If everything works: Great, if not: Restore container from backup).