I've been meaning to post a forum question for well maybe over a year.

UnRAID 7.2.4 - installed on a Intel NUC 11 Extreme Kit (NUC11BTMi9) Mini PC - Core i9-11900KB, using Samsung 4TB NVMe, for cache.

It was stable, and then I started getting complete restarts, when using VMs, and I suspected it was because I was using nested ESXi.

Earlier I decided to upgrade to 7.3.2, and to my amazement, managed to get 29 days of uptime with no issues or restarts, which was a bonus, as previously it would restart at least every two days, I then decided it was about time to setup a new syslog to harvest all the messages, so I could refer to later.

But, recently I noticed the all the VMs had stopped, but oddly the server had not restarted.

I noticed BTRFS errors on the cache, and it was put into read only mode, and hence all the VMs stopped.

BTRFS error (device nvme2n1p1 state EA): parent transid verify failed on logical 4693510684672 mirror 2 wanted 585721 found 585705

I copied all the data off the NVMe devices, and found no errors, and on restart and the scrub found no errors.

Checking syslog, I can see this sort of activity recently

2026-09-24T03:02:50+01:00 root: /mnt/cache: 212.4 GiB (228075569152 bytes) trimmed on /dev/nvme2n1p1

2026-09-24T03:02:50+01:00 kernel: I/O error, dev loop2, sector 85536 op 0x3:(DISCARD) flags 0x800 phys_seg 1 prio class 2

2026-09-24T03:02:50+01:00 kernel: BTRFS warning (device loop2 state EA): failed to trim 1 block group(s), last error -5

2026-09-24T03:02:50+01:00 kernel: I/O error, dev loop2, sector 85536 op 0x3:(DISCARD) flags 0x800 phys_seg 1 prio class 2

2026-09-24T03:02:50+01:00 kernel: BTRFS warning (device loop2 state EA): failed to trim 1 block group(s), last error -5

2026-09-24T03:02:50+01:00 kernel: I/O error, dev loop3, sector 37832 op 0x3:(DISCARD) flags 0x800 phys_seg 1 prio class 2

2026-09-24T03:02:50+01:00 kernel: I/O error, dev loop3, sector 75776 op 0x3:(DISCARD) flags 0x800 phys_seg 1 prio class 2

2026-09-24T03:02:50+01:00 kernel: BTRFS warning (device loop3 state EA): failed to trim 2 block group(s), last error -5

I also notice MCE errors, but I've ran memtest86+ for over 24 hours, and no issues are detected with memory.

It would seem since, restarting today 25th, after memtest86+ all is well, and after the scrub found no errors, just trying to identify why it went offline.

btrfs scrub status /mnt/cache
UUID: e859fbd1-6099-4943-8c4f-3cb5f630dca8
Scrub started: Fri Sep 25 11:18:10 2026
Status: finished
Duration: 0:22:15
Total to scrub: 5.97TiB
Rate: 4.58GiB/s
Error summary: no errors found

because at present its not been a very stable server, and I'm trying to consolidate 7 Synology NAS, and two Storage Servers, and many ESXi servers and home labs - to reduce electricity costs. But don't have issues with Synology, Storage Servers and ESXi servers in terms of stability. It could be a faulty Intel NUC 11 Extreme Kit (NUC11BTMi9) Mini PC or not suitable, but would rather not waste my time, if this is going to be a long term issue, don't get me wrong had UnRAID running on other mobos with no issues for years.

Comments ?

Attach Diagnostics ZIP to your NEXT post in this thread.

Setup Syslog Server.