UCS No bootable Device Detected

As the title says “No bootable Device Detected”. Had a power supply problem due to power failure which “forced” my server to shut down without any power. I tried to restart my server (ZotacBox C327) this evening but “No bootable Device Detected” are detected. Any Ideas here apart reinstalling totally the system (and buying an emergency power supply for the next time) ? Any Ideas about repair disks like Rescatux https://www.supergrubdisk.org/rescatux/ to reboot the machine and repair UCS disk failures to reboot on normal harddrive?

Any help would be welcome (running the system since first first corona lockdown to help my wife in her teachers job without any help of the official institutions. I deliberately choose a hardcore test strategy (without any backups) due to the lack of time and disposability of server components in march 2020 and time goes by…)

Would be happy any reaction before completly reinstalling my system.
Yours mangrovenjazz

This method (bootable usb stick) allowed my to start the server. How ever when logging in I get the following error

Internal server error: The service is temporarily not available.

Konnte nicht zum LDAP-Dienst verbinden.
Fehlermeldung: error:1416F086:SSL routines:tls_process_server_certificate:certificate verify failed (certificate is not yet valid)

Die folgenden Schritte können helfen, das Problem zu beheben:

  • Überprüfen Sie die SSL Zertifikate, Proxy- und Firewall-Einstellungen
  • Falls die SSL Zertifikate abgelaufen sind oder das Wurzelzertifikat kürzlich erneuert worden ist, bitte ziehen Sie http://sdb.univention.de/1000 zu rat.
  • Starten Sie den LDAP-Dienst entweder über “service slapd restart” per Kommandozeile oder mit dem UMC Modul “Systemdienste” auf dem Domänencontroller Master neu
  • Installieren Sie alle Softwareaktualisierungen

I attached a keyboard and screen to the server and logged in as admin. Trying sudo “service slapd restart” did not show any result.

Any further ideas welcome

Check time and timezone on your server!