Hi, we are experiencing a weird issue with our Ovirt setup. We have two physical hosts (DC1 and DC2) and mounted Lenovo NAS storage for all VM data. They are connected via a managed network switch. What happens is that if switch goes down for whatever reason (firmware update etc), physical host reboots. Not sure if this is an action performed by Ovirt but I suspect it is because connection to mounted storage is lost and it  performs some kind of an emergency action. I would need to get some direction pointers to find out a) who triggers the reboot and why c) a way to prevent reboots by increasing storage? timeouts Switch reboot takes 2-3 minutes. These are the host /var/log/messages just before reboot occurs: Sep 28 16:20:00 ovirtnode02 sanlock[10993]: 2021-09-28 16:20:00 7690984 [10993]: s11 check_our_lease warning 72 last_success 7690912 Sep 28 16:20:00 ovirtnode02 sanlock[10993]: 2021-09-28 16:20:00 7690984 [10993]: s3 check_our_lease warning 76 last_success 7690908 Sep 28 16:20:00 ovirtnode02 sanlock[10993]: 2021-09-28 16:20:00 7690984 [10993]: s1 check_our_lease warning 68 last_success 7690916 Sep 28 16:20:00 ovirtnode02 sanlock[10993]: 2021-09-28 16:20:00 7690984 [27983]: s11 delta_renew read timeout 10 sec offset 0 /var/run/vdsm/storage/15514c65-5d45-4ba7-bcd4-cc772351c940/fce598a8-11c3-44f9-8aaf-8712c96e00ce/65413499-6970-4a4c-af04-609ef78891a2 Sep 28 16:20:00 ovirtnode02 sanlock[10993]: 2021-09-28 16:20:00 7690984 [27983]: s11 renewal error -202 delta_length 20 last_success 7690912 Sep 28 16:20:00 ovirtnode02 wdmd[11102]: test warning now 7690984 ping 7690970 close 7690980 renewal 7690912 expire 7690992 client 10993 sanlock_hosted-engine:2 Sep 28 16:20:00 ovirtnode02 wdmd[11102]: test warning now 7690984 ping 7690970 close 7690980 renewal 7690908 expire 7690988 client 10993 sanlock_3cb12f04-5d68-4d79-8663-f33c0655baa6:2 Sep 28 16:20:01 ovirtnode02 systemd: Created slice User Slice of root. Sep 28 16:20:01 ovirtnode02 systemd: Started Session 15148 of user root. Sep 28 16:20:01 ovirtnode02 systemd: Removed slice User Slice of root. Sep 28 16:20:01 ovirtnode02 sanlock[10993]: 2021-09-28 16:20:01 7690985 [10993]: s11 check_our_lease warning 73 last_success 7690912 Sep 28 16:20:01 ovirtnode02 sanlock[10993]: 2021-09-28 16:20:01 7690985 [10993]: s3 check_our_lease warning 77 last_success 7690908 Sep 28 16:20:01 ovirtnode02 sanlock[10993]: 2021-09-28 16:20:01 7690985 [10993]: s1 check_our_lease warning 69 last_success 7690916 Sep 28 16:20:01 ovirtnode02 wdmd[11102]: test warning now 7690985 ping 7690970 close 7690980 renewal 7690912 expire 7690992 client 10993 sanlock_hosted-engine:2 Sep 28 16:20:01 ovirtnode02 wdmd[11102]: test warning now 7690985 ping 7690970 close 7690980 renewal 7690908 expire 7690988 client 10993 sanlock_3cb12f04-5d68-4d79-8663-f33c0655baa6:2 Sep 28 16:20:02 ovirtnode02 sanlock[10993]: 2021-09-28 16:20:02 7690986 [10993]: s11 check_our_lease warning 74 last_success 7690912 Sep 28 16:20:02 ovirtnode02 sanlock[10993]: 2021-09-28 16:20:02 7690986 [10993]: s3 check_our_lease warning 78 last_success 7690908 Sep 28 16:20:02 ovirtnode02 sanlock[10993]: 2021-09-28 16:20:02 7690986 [10993]: s1 check_our_lease warning 70 last_success 7690916 Sep 28 16:20:02 ovirtnode02 wdmd[11102]: test warning now 7690986 ping 7690970 close 7690980 renewal 7690916 expire 7690996 client 10993 sanlock_15514c65-5d45-4ba7-bcd4-cc772351c940:2 Sep 28 16:20:02 ovirtnode02 wdmd[11102]: test warning now 7690986 ping 7690970 close 7690980 renewal 7690912 expire 7690992 client 10993 sanlock_hosted-engine:2 Sep 28 16:20:02 ovirtnode02 wdmd[11102]: test warning now 7690986 ping 7690970 close 7690980 renewal 7690908 expire 7690988 client 10993 sanlock_3cb12f04-5d68-4d79-8663-f33c0655baa6:2 Sep 28 16:20:03 ovirtnode02 sanlock[10993]: 2021-09-28 16:20:03 7690987 [10993]: s11 check_our_lease warning 75 last_success 7690912 Sep 28 16:20:03 ovirtnode02 sanlock[10993]: 2021-09-28 16:20:03 7690987 [10993]: s3 check_our_lease warning 79 last_success 7690908 Sep 28 16:20:03 ovirtnode02 sanlock[10993]: 2021-09-28 16:20:03 7690987 [10993]: s1 check_our_lease warning 71 last_success 7690916