openHAB crashed, log full of NUL bytes

This morning I recognized openHAB had crashed and was no longer available by any GUI or even PuTTY. After switching power off and back on I could see very little info about the issue in the log.

As NUL bytes are not shown in code fences I’ll post a screenshot of the log.


The line has 1148 NUL bytes if that is any valuable information and the CPU temperature just before the crash was 53.7 °C. openHAB has been up and running for weeks before.

So I pretty much know WHEN the problem happened, but I have no clue, WHAT was the problem and HOW I could find it.

Any suggestion is very welcome!

  • Platform information:
    • Hardware: Raspberry Pi 3B
    • OS: openHABian
    • Java Runtime Environment: which java platform is used and what version
    • openHAB version: 2.5.1-2 (Release Build)
    • Memory: SanDisk Extreme PRO USB 3.1 Solid State

Neither do we. It’s no wellknown issue.
If I was to guess, your SD card got corrupted.
To play it safe, exchange it and use ZRAM next time.

Thank you for the hint. Actually I’m not using an SD card (sorry to miss that info in the original post; edited it now to include it).
The whole system runs and boots from SanDisk Extreme PRO USB 3.1 Solid State.

That is a USB stick that can get corrupted the same as an SD Card.

Basically true, but I thought to have picked an option with extremely low chance for such failure. I intentionally didn’t use a cheap USB stick I had laying around but a solid state flash drive with way too much capacity for wear leveling and “liftime warranty”.
Is there any way to find out for sure?

SSDs are a different architecture that USB Sticks and SD Cards.

Exactly. So my current understanding is that the stick I have is technically a SSD, just with a shape similar to a USB stick, thus being much more reliable than SD cards or USB sticks. Therefore I would be surprised if the issue is caused by corrupted memory.
But I’m not a memory technology professional and somehow have to rely on the way too often exaggerated marketing statements. So I may be totally wrong and have wasted a lot of money on a USB stick.

I don’t think so. That would require a battery and a DRAM cache, eventually, both of which I think your stick does not have. There’s no way to verify if that truely is the cause of your problems, but short of other information, it’s not unreasonable to believe in that. Also check this post.

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It’s important to realize that power failures can and will also cause file system corruptions, especially on flash memory. 3.5" type SSDs can also have this problem though they often have room to insert some capacitors or batteries that give the SSD enough time to dump out the currently ongoing writes before the drive loses all power. That is almost certainly not going to be available in a thumb drive form factor.

I agree that it’s unlikely that this drive has worn out, but that’s not the only way the file system can become corrupted.

But all appearances something that makes up openHAB’s program git corrupted somehow. So regardless of the root cause, I’d recommend a rebuild of the system or restore from backup.

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Alright, thank you all very much for your support.
Actually there has been a power outage during the recent storm Ciara. That would make sense.
I’ll make another backup, set the system up from scratch and urgently finish my UPS setup (parts laying here for months now).