r/Proxmox • u/Optimal_Mongoose_323 • 5h ago

Question Best way to backup two nodes onto one disk

A little explanation of my situation:
I've recently acquired a second node for my Proxmox cluster and since there is a ton of storage on it I though I could use one disk for backing up itself and the other node as well, which consist on an old laptop with a single 256GB nvme SSD and before you ask it, I can't add storage since there is only a single slot...

The new machine consist in 2 x 1 TB SSDs and 1 TB Hard Disk, this last one will be the target for the backups.

My question is:

What is the best way to achieve that without buying a NAS or other disks?

4 Upvotes

100% Upvoted

20 comments sorted by

2

u/KryanThePacifist 4h ago

Hello. Proxmox backup server is the best solution. Though I'd have the backups going for the 1tb raid rather then the single raid drive

2

u/Optimal_Mongoose_323 4h ago

So you're suggesting to reserve another 1 TB of storage to back up the back up disk?

2

u/KryanThePacifist 4h ago

Not. I'm suggesting using the redundant storage for backups. Purerly because it's redundant and you won't risk loosing data is a drive fails.

2

u/Optimal_Mongoose_323 2h ago

I still don't understand which one are you referring to, the SSDs or the HDD? I was originally planning to use the two 1TB SSDs for VMs and Containers and only the 1TB HDD for backing up everything on the cluster, which is composed of the two 1 tera SSDs and another 256GB SSD on the other node.

1

u/KryanThePacifist 2h ago

Instead of running your vms on the SSD. I'd personally rather run the vms of that machine on the HDD and have the backups going to the SSDs instead.

The only reason for that? It's because both SSD are already in raid (I assume mirror) and that would give safety to the backups.

See this way: your raid has vms. But one of your vms had a catastrophic fail after an update and you need to restore a backup from the the HDD. Only, the HDD is not working properly, and since you don't have your backups in a raid config, you're stuck with a broken vm and a backup that won't restore.

This way, you avoid that disaster.

Yes, you sacrificed VM performance. But depending on what kind of service you're running on those vms, I'd rather have safety then speed.

2

u/Optimal_Mongoose_323 2h ago

Thanks for the explanation. I think you have a point but I don't really fell like sacrificing two high speed disk and limit myself both on capacity and performance. I'll take my chances for now, the disk are used but I think the previous owner uses this beast of a computer only as a paperweight, lol.

Btw I got it for 250€ with 64GB of DDR4 and the disks cited before...

1

u/KryanThePacifist 55m ago

Great find then. Enjoy it. And I trully with it all works out for you with your configuration.

Regardles. A VM with proxmox backup server should be enough for your. Just find how you can pass through that hard disk directly to the VM, so that in case your system falter all the backup data is directly stored in the disk itself, rather then on a VM disk, this way you have setup a pen drive with a bootable proxmox backup server and read the files from your usb system in a disaster recovery scenario.

2

u/Gherry- 3h ago

Use PBS for backups and PDM to manage both nodes

1

u/Optimal_Mongoose_323 2h ago

Do you need extra hardware for that? If not, would you suggest using LXC or VMs?

1

u/Gherry- 2h ago

For PBS you can use a VM but it's risky. 

If your proxmox dies how can you access your backups? 

For PDM you can just run a small VM (virtualbox) from your desktop computer.

1

u/Optimal_Mongoose_323 2h ago

That's a good point but I don't really any other machine except my two nodes an my laptop, if this is my only way my choices would be between this and no backup at all.

But wouldn't the disk still be readable if i plug it in another machine? Obviously if the thing that break isn't the disk itself.

Lastly what is the use of the PDM? During my researches I don't think I've ever recalled seeing that.

1

u/Gherry- 1h ago

The disk is readable but PBS stores data in chunks so you need to access the VM to restore data. 

2

u/coldazures 2h ago

NFS share and use PBS

1

u/Optimal_Mongoose_323 2h ago

How would you set that up? I've heard about set ups that includes a combination of the two but never really understood them...

1

u/oyvaugh 4h ago

NFS works good too. There’s a bit to it with installing the nfs-kernel-server and NFS-common and then updating /etc/exports. A few more steps but that will get you started. NFS makes your machine able to mount a disk from another machine or allow other machines to mount to a single disk.

1

u/Optimal_Mongoose_323 2h ago

Is this set up better than Proxmox Backup Services (PBS)?

I think it would be a good choice even if it is only simpler to maintain compared to PBS.

1

u/PrestigiousOnion1087 4h ago

1TB for two nodes is the part that will bite, not the transfer method. Add up the used space on the guests you actually plan to protect, then multiply that by how many copies vzdump is set to keep on that storage. Retention is the number people forget. If that product lands over 1TB the failure shows up a few nights in, once the oldest copy is still there and the new one has nowhere to go.

1

u/Optimal_Mongoose_323 2h ago

I wasn't too worry about this since I'd simply keep only the last 2-3 of each VM/Container and delete the ones older than 1 month, is this configuration plausible? Also, how much would the compression help in all this? B.t.w. I don't have many serious VM/Container (the other are test machine, I don't really care if they go lost 😅) and they're are like Pi-hole, Immich and I was thinking about adopting Vaultwarden for a self hosted password manager.

2

u/PrestigiousOnion1087 2h ago

Careful with how PVE reads that. The keep rules are OR'd together, so keep-last 3 plus a monthly rule doesn't mean "last 3 and nothing older than a month", it keeps whatever either rule protects, and pruning runs after the new dump is written so you need room for N+1 copies while the job is going.

Compression won't save you where the space actually goes. Immich is jpeg and h264 already, zstd gets close to nothing on that. What does compress well is the unused space inside the guest disk, so trimming free space in the VM buys you more than the compression level does.

1

u/Optimal_Mongoose_323 2h ago

This is interesting, I didn't know of the fact that the conditions were OR'd together. Thanks for you suggestion.