Risks involved with restoring Umbrel from snapshot

Hello all. This is my first message here so I hope to be in the correct section.

On https://plebnet.wiki/wiki/Node_Hardware, I read:

For the host operating system, Proxmox is a great open source virtualization platform based on QEMU/KVM. You can then set up your disks as a ZFS storage pool with mirroring which instantly gets you local storage redundancy. If one disk fails, you won’t lose any data and when you replace the drive the mirroring brings the new disk up to speed automatically. Couple that with ZFS snapshots that can be created at no cost (due to CoW) and sent off site and you have a pretty robust and reliable setup with hardware that is designed to take a beating 24/7 for years. Be aware that you should never restore an old image of an LND database, doing so could expose you to risk of transmitting an old state and loss of funds.

Your Lightning node software of choice can then be run in a VM.

This is exactly the configuration I am running Umbrel on. But I am a bit confused:

  • first it praises the merits of ZFS snapshots
  • then it states an old image of an LND database should not be restored

So my question is simple: if I snapshot my Virtual Machine on January 1st, can I safely rollback to this snapshot on January 2nd? Or is it dangerous because the balances of my channels will have changed by then? I understand this situation is dangerous when closing channels after the rollback because:

  • if I close a channel, I can mistakenly claim a wrong balance so the other party can have it all
  • if the other party closes a channel with a fraudulent balance, I might not be able to prove the correct balance on my side

But if I rollback on January 2nd and don’t close any channel, is it possible for Umbrel to safely restore the correct balance of each channel by “talking” with the other parties (before they try to close a channel)? Or maybe the correct balance for each channel will only be restored after a transaction?

Virtual Machine snapshots are incredibly convenient when tinkering/upgrading but I am just trying to evaluate the risks involved.

Thank you very much for your comments

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