Can my backup really be restored?
That question cannot be answered from the backup report — only by trying. This page explains the depths of testing there are, what each of them proves, and what you need for a test worth relying on.
What a green backup report proves — and what it does not
Backup software reports success when a job has run without errors. That is a statement about the job, not about your company. The report does not know which systems are business-critical. It does not know whether a server set up two years ago was ever added to the backup plan. And it does not know whether the systems it saved add up to a working whole again.
That is precisely where the gap lies. Most companies that fail when it matters do not fail because no backup existed. They fail on details nobody checked beforehand: a missing licence server, a service that will not start without a reachable domain controller, an application whose configuration points at an IP address that does not exist in the new environment.
Dependencies like these appear in no documentation — they only become visible when you actually carry the restart out.
Four levels, four very different statements
People who say „we test our backups“ often mean one of the lower levels. The difference is considerable.
The job completed
The backup was created. What it tells you: the job worked. About the contents it says nothing.
The backup is readable and verified
Checksums match and the backup can be opened. Proxmox Backup Server, for instance, can verify this itself. What it tells you: the data is technically intact.
Individual data or systems can be written back
The classic restore test. What it tells you: the way back works for whatever was tested. Whether the system is then fit to work remains open.
A running environment emerges from the backups
The systems are restored, started and connected into a coherent environment in which you check your processes. What it tells you: your company can start again from these backups — or it cannot, and you know why.
- recovery lab test
- restart
- customer test
What a test needs from you
Preparation decides how much the test is worth. The volume of data is not the problem; unclear expectations are. Anyone who does not settle beforehand what should work at the end cannot say afterwards whether the test succeeded.
So before the test we clarify the scope, the format of your backups and the question of which software the restore needs. You provide that backup software and its licences; we provide the recovery environment and carry out the restore.
Which systems are included — and in what order do they have to start?
What did the backing up, and how does the data reach us?
What do you already know about services waiting on each other? The test finds the rest.
Which processes have to be demonstrably running at the end? You set those, not us.
Frequently asked questions about testing restores
How do I spot that my backup is only apparently fine?
A green backup report tells you a job ran to completion. It says nothing about whether the state captured is consistent, whether every business-critical system is included in the job, or whether a running operation can be built from it. Forgotten systems typically only come to light when you rehearse the whole restart once.
Isn't it enough to pull back a file now and then?
For the question „is the backup readable?“, yes. For the question „will my company run again?“, no. A single restored file says nothing about bootability, system dependencies, or whether your applications will start without the production environment around them.
What do you need from me for a test?
Which systems are in scope, what format the backups are in, which dependencies you already know about and which business processes should be checked at the end. For the enquiry we need no credentials, no IP ranges and no information about where your backups are stored.
Do I have to test every system?
No. What usually makes sense is the core that carries the business: directory service, database, the central line-of-business application and the systems without which the others cannot work. The scope is agreed together before the test.
Who checks at the end whether the applications run?
You do. We restore, start the systems and give you controlled access to the isolated environment. Whether your business application is behaving correctly can only be judged by the people who use it every day.
More on this: disaster recovery test for the planned emergency, Proxmox recovery for environments with Proxmox Backup Server — or back to the overview in the Recovery Lab.