Host reboot

[VecH]

Installed Proxmox on RAID 1 (ZFS)
Created guest for Windows 2012 R2 Standard x64
Installed guest operating system
When you install an update for Window (or other software), the host system crashes

I am connected remotely, where to read and how to diagnose these faults?

in /var/log/syslog and syslog.1 there is nothing special, there are no records about the services stop before the reset

root@pve:~# last
root     pts/0        10.2.33.5        Wed Jul 18 16:26   still logged in
reboot   system boot  4.15.17-3-pve    Wed Jul 18 16:26   still running
reboot   system boot  4.15.17-3-pve    Wed Jul 18 15:04   still running
reboot   system boot  4.15.17-3-pve    Wed Jul 18 14:59 - 15:04  (00:04)
reboot   system boot  4.15.17-3-pve    Wed Jul 18 14:03 - 15:04  (01:00)
root     pts/0        10.2.33.5        Tue Jul 17 21:45 - crash  (16:18)
reboot   system boot  4.15.17-3-pve    Sat Jul  7 06:15 - 15:04 (11+08:48)
root     pts/0        10.2.33.5        Thu Jul  5 14:22 - 14:43  (00:21)
root     pts/0        10.2.33.5        Mon Jul  2 17:24 - 21:47  (04:22)

 

[VecH]

root@pve:~# cat /etc/pve/qemu-server/102.conf
agent: 1
bootdisk: sata0
cores: 4
ide0: local:iso/virtio-win-0.1.141.iso,media=cdrom,size=309208K
memory: 4096
name: Win2012r2-Backup
net0: e1000=66:A8:0E:5A:BD:8E,bridge=vmbr0
numa: 0
onboot: 1
ostype: win8
sata0: local-zfs:vm-102-disk-1,size=50G
sata1: /dev/disk/by-id/ata-WDC_WD60EFRX-68L0BN1_WD-WX11D278Z56Y,backup=0,size=5860522584K
scsihw: virtio-scsi-pci
smbios1: uuid=b9b2592e-24fb-4abb-b631-aa5fbdedc107
sockets: 1

 

[VecH]

balloon: 0

Exposed parameter, it has not been rebooted for an hour and a half already

what could be the problem?

 

[VecH]

The problem remains, the host is rebooting