For the past two months, my previously stable Unraid server (running fine for ~1 year) has been experiencing unexplained, sudden reboots. The key issues are:

1. Random Reboots: The system reboots without warning, logs, or error messages. It behaves like a sudden power cut followed by an immediate restart.

2. Array Failure: These reboots eventually led to the main array failing to start.

3. ZFS Mirror Crash: Attempting to start the array (which includes a ZFS mirror pool of SSDs) causes the system to either reboot instantly or freeze completely indefinitely (observed when trying Safe Mode).

4. Hardware Replacement Didn't Fix: Suspecting the SSDs, I backed up data, replaced both SSDs with new ones, and created a completely new configuration. The array started successfully initially.

5. Problem Recurrence: Unfortunately, the sudden, unexplained reboot symptom has now occurred again even with the new hardware and configuration.

The core problem persists: sudden, unlogged reboots, now happening even after replacing the SSDs and rebuilding the ZFS pool.

bnas-diagnostics-20250727-1653.zip

Random reboots are almost always a hardware issue, since you have multiple RAM sticks, try using the server with just one , if the same try with the other one, that will basically rule out bad RAM.

Also, which CPU is this? Is it an engineering sample?

Model name: Genuine Intel(R) 0000

Thanks for the suggestion regarding the RAM. That's definitely a logical next step.

To provide an update:

1. RAM Tested: I did run an extended memtest yesterday. It ran without errors for several hours, but unfortunately, the system still experienced a sudden reboot during or after the test period.

2. CPU Information: You asked about the CPU - this is a key point I hadn't mentioned before. Yes, it is an Engineering Sample (ES) CPU.

3. Action Plan: Given the memtest results and the fact it's an ES CPU (which can sometimes be unstable), I have already ordered a standard, retail CPU to replace it.

4. Next Steps: My plan is to:

   • Wait for the new retail CPU to arrive.

   • Install it.

   • Then restart the troubleshooting process from the beginning, including rigorous memory testing with the new CPU installed.