Mergerfs together with snapraid

What hardware are you using?

Have you looked at SMART stat's for the drives?
(And)
Are you booting on the SSD?

You might consider reseating the PCI to SATA card. (Free and easy.)

I think what crashtest is saying is:

- Turn off the server.

- Extract the pcie to sata card.

- Connect the card again.

- Start the server.

This can work if it is not connected well or makes poor contact.

I asked about your hardware because the symptoms suggest a hardware problem rather than a software problem. And in fact, there are several aspects of your setup that catch my attention.

1. The pcie to sata card. If you look at the manufacturer's website, this card has a port multiplier chip. This is not ideal and can cause problems, access to the disks is not simultaneous. At least you don't have a real Raid set up, don't do it or you'll be in real trouble. I'm not sure how that might affect a setup with SanpRaid.

2. The picoPSU power supply. I don't know that brand but for the price I would say it shouldn't be very good. If the power supply is not correct you can lose access to the hard drives.

I would be inclined to do a test run with a standard power supply that you can have around the house for a while. If you check that everything is working normally, you already have the cause of the problem.

If it still doesn't work, go to the next point. Check if the pcie to sata card is the cause.

The first thing I would do is connect the parity hard drive to the sata port that you have free. This won't cost you any money. It might fix it, try it for a while.

If it is not solved, it would go to the card itself. Since the pcie port on this board is x1, finding a 4-port card without a port multiplier is going to be difficult, but since you have the mini pcie port occupied you have no choice but to use the pcie port for the hard drives. You'll probably only find two-port adapters if you stick to those without a multiplier. But since you have a sata port you can connect a hard drive to that port and it would be enough for your current setup, although it will limit your future expansion. In this post there is information on how to find suitable pcie to sata adapters. Why I chose an N100 over a Raspberry PI5

I forgot, ram is not specified in the list of supported ram by the motherboard manufacturer. That could also cause problems. If all of the above doesn't work, I would try replacing it with a supported RAM module.

Quote from Stasys

How to do that reseating?

Literally unplug the SATA card and plug in back in.

Quote from chente

I think what crashtest is saying is:

- Turn off the server.

- Extract the pcie to sata card.

- Connect the card again.

- Start the server.

Exactly. While there's a relatively low chance that this will correct an issue, it's free, easy and worth a try.

Quote from chente

I forgot, ram is not specified in the list of supported ram by the motherboard manufacturer. That could also cause problems. If all of the above doesn't work, I would try replacing it with a supported RAM module.

This is a good reason to run a test using -> Memtest86

For those who may be reading this thread - for future ref:

For the best use experience and to aid those who are attempting to support OMV, it's best not to add 3rd party packages until well after your installation is up, running, and fully configured. Even for an experienced Linux user, becoming familiar with the way OMV operates takes a bit of time. Then, after a reasonable period of time that could be called "familiarization" and "baselining", admin's might consider adding on packages, one at a time, while watching for potential side effects..