My server started crashing randomly after months of stable uptime. The crashes have no obvious trigger and have left nothing useful in syslog. Key symptoms:

• Server completely frozen — web UI unreachable, shares dropped, Docker containers unresponsive

• Still pingable after the crash (network stack survived)

• Nothing in syslog at the crash point — logging just stopped

• XFS journal recovery running on all 5 array disks on every boot (confirming unclean shutdown each time)

• Crashes happening on a very consistent 12 hour interval after each reboot

System specs

• Unraid 7.1.4, kernel 6.12.24

• 31 GiB RAM, no swap configured

• 5 array disks (2× ST12000NM0127, 2× ST14000VN0008, 1× WD30EFRX) + WD140EDFZ parity

• 1TB Crucial P310 NVMe cache

• ~30 Docker containers including Plex, Jellyfin, Sonarr, Radarr, qBittorrent, Bitmagnet, AdGuard

• 1 VM: Home Assistant OS 13.1 (qcow2)

• NIC: Realtek RTL8111/8168 (not the problematic RTL8126)

What I ruled out

• RAM — all SMART and memtest clean, no OOM killer events in logs

• Thermals — all drives under 44°C, no CPU throttling

• NVMe — 100% available spare, 2% endurance used, zero media errors, never throttled

• Network driver — RTL8111 is stable and well-supported, not the buggy RTL8126

• Disk health — all SMART attributes clean, zero pending/uncorrectable sectors

• Docker memory leak — RAM available actually increased slightly over 10 hours (though Bitmagnet grew ~340 MiB in 10 hours, worth watching)

Attach Diagnostics ZIP to your NEXT post in this thread.

Here are diagnostics:
phyllis-diagnostics-20260406-1246.zip

If the issue started out of the blue and there's nothing logged, it may have developed a hardware issue, start by running memtest, if nothing is found , you can try to boot the server in safe mode with all docker containers/VMs disabled, let it run as a basic NAS for a few days, if it still crashes it's likely a hardware problem, if it doesn't start turning on the other services one by one, including the individual docker containers.