Problem with NVMe system drive

First let me say that I am a Linux and OMV noob. I am not a complete NAS noob owning both a Synology and TerraMaster NAS. But I am trying to replace one or maybe both of them as well as learn stuff along the way.

I found a video on Youtube that walked me thru setting up OMV 6.5 and I have been playing with testing the setup using this video. I currently have it working very well on one of my home built PCs.. (cheap mini-ITX SZMZ Chinese MB, 1tb NVMe system drive & 4x2tb SSD data drives). This is my best attempt yet out of maybe ten tries...

However during all of these attempts, I have run into a strange situation... strange to me anyway.

If I were to power down the PC and remove the 'working' NVMe system drive and 4xdata drives, put another system drive in it (maybe windows or something), do some stuff and then shut it down again and re-install the working OMV system drive & data drives, the PC will not reboot. OMV will not reboot. Even setting the boot device in PC BIOS setup will not fix it.

First thing I thought was bad NVMe... except it has now done it on three different NVMe drives.

Next I thought, bad motherboard but I tried a second cheap micro-ATX Chinese MB (manuf unknown), and it does the same thing.

I am hoping someone will tell me that this is a security thing and there is an easy fix for it. I don't want to have to go thru this (setting OMV up from scratch) again but you know I am dying to remove the system drive on this beautifully working system just to see what happens...

Any ideas would be greatly appreciated...

Thanks for the info... I believe you hit the nail right on the head. I went ahead and setup a 2nd NAS on the other MB and now have both working.

I removed and re-installed both NVMe drives and all was well. I was even able to duplicate the problem by changing the MB in setup from UEFI to Legacy only... and then fixed it by switching it back and reselecting the debian drive designation rather than the raw NVMe drive designation.

Now my next task is to setup one using RAID 10 instead of RAID 5... fun stuff.

Quote from macom

You should use OMV7 as OMV6 is end of life for a looooong time.

Yes, I realize that but the only video I found (that I could watch) was using OMV 6.x, so I went that route for my initial test system. Currently, I am working on getting 7.7.10-1 working.

Always looking for more videos to watch...

Yes... the doc was very good. And very similar to the video I watched. I was able to get a RAID 5 v7.x system setup with little or no trouble. What I need now is to find some doc on setting up RAID 10. I have been unable to find docs or videos on this subject.

It appears that it can be done in the GUI, but I just do not have the skillset to figure out the correct order of operations. I'll have some time to play with it over the weekend and hopefully make some progress.

So... I set up a ZFS system in OMV 7 and mirrored the drives. It looks to be working fine. One thing bothers me though. Last night after copying about 100gb of files to it, the memory did this. It was still like this 8 hours later... is this Flashmem?

Cool. I noticed that when I deleted all my files and then removed them from .recycle, the RAM returned to normal.

No I read it after my response above. It was interesting and informative.