Hi All, I did began a very big project, I've started upgrade a cluster from 3.5 to 4.3... It was a mistake:( Since upgrade, I can't start the host. The UI seems to working fine. [root@virt ~]# service vdsm-network start Redirecting to /bin/systemctl start vdsm-network.service Job for vdsm-network.service failed because the control process exited with error code. See "systemctl status vdsm-network.service" and "journalctl -xe" for details. [root@virt ~]# service vdsm-network status Redirecting to /bin/systemctl status vdsm-network.service ● vdsm-network.service - Virtual Desktop Server Manager network restoration Loaded: loaded (/usr/lib/systemd/system/vdsm-network.service; disabled; vendor preset: enabled) Active: failed (Result: exit-code) since Thu 2019-04-04 15:03:44 CEST; 6s ago Process: 19325 ExecStart=/usr/bin/vdsm-tool restore-nets (code=exited, status=1/FAILURE) Process: 19313 ExecStartPre=/usr/bin/vdsm-tool --vvverbose --append --logfile=/var/log/vdsm/upgrade.log upgrade-unified-persistence (code=exited, status=0/SUCCESS) Main PID: 19325 (code=exited, status=1/FAILURE) Apr 04 15:03:44 virt.bolax.hu vdsm-tool[19325]: return tool_command[cmd]["command"](*args) Apr 04 15:03:44 virt.bolax.hu vdsm-tool[19325]: File "/usr/lib/python2.7/site-packages/vdsm/tool/restore_nets.py", line 41, in restore_command Apr 04 15:03:44 virt.bolax.hu vdsm-tool[19325]: exec_restore(cmd) Apr 04 15:03:44 virt.bolax.hu vdsm-tool[19325]: File "/usr/lib/python2.7/site-packages/vdsm/tool/restore_nets.py", line 54, in exec_restore Apr 04 15:03:44 virt.bolax.hu vdsm-tool[19325]: raise EnvironmentError('Failed to restore the persisted networks') Apr 04 15:03:44 virt.bolax.hu vdsm-tool[19325]: EnvironmentError: Failed to restore the persisted networks Apr 04 15:03:44 virt.bolax.hu systemd[1]: vdsm-network.service: main process exited, code=exited, status=1/FAILURE Apr 04 15:03:44 virt.bolax.hu systemd[1]: Failed to start Virtual Desktop Server Manager network restoration. Apr 04 15:03:44 virt.bolax.hu systemd[1]: Unit vdsm-network.service entered failed state. Apr 04 15:03:44 virt.bolax.hu systemd[1]: vdsm-network.service failed. Since, the host does not start. Apr 04 14:56:00 virt.bolax.hu libvirtd[17705]: 2019-04-04 12:56:00.764+0000: 17705: error : virNetSocketReadWire:1806 : End of file while reading data: Input/output error Apr 04 14:56:00 virt.bolax.hu libvirtd[17705]: 2019-04-04 12:56:00.965+0000: 17709: error : virNetSASLSessionListMechanisms:393 : internal error: cannot list SASL ...line 1757) Apr 04 14:56:00 virt.bolax.hu libvirtd[17705]: 2019-04-04 12:56:00.966+0000: 17709: error : remoteDispatchAuthSaslInit:3440 : authentication failed: authentication failed Apr 04 14:56:00 virt.bolax.hu libvirtd[17705]: 2019-04-04 12:56:00.966+0000: 17705: error : virNetSocketReadWire:1806 : End of file while reading data: Input/output error Apr 04 14:56:01 virt.bolax.hu libvirtd[17705]: 2019-04-04 12:56:01.167+0000: 17710: error : virNetSASLSessionListMechanisms:393 : internal error: cannot list SASL ...line 1757) Apr 04 14:56:01 virt.bolax.hu libvirtd[17705]: 2019-04-04 12:56:01.167+0000: 17710: error : remoteDispatchAuthSaslInit:3440 : authentication failed: authentication failed [root@virt ~]# service vdsm-network status Redirecting to /bin/systemctl status vdsm-network.service ● vdsm-network.service - Virtual Desktop Server Manager network restoration Loaded: loaded (/usr/lib/systemd/system/vdsm-network.service; disabled; vendor preset: enabled) Active: failed (Result: exit-code) since Thu 2019-04-04 15:00:39 CEST; 2min 49s ago Process: 19079 ExecStart=/usr/bin/vdsm-tool restore-nets (code=exited, status=1/FAILURE) Process: 19045 ExecStartPre=/usr/bin/vdsm-tool --vvverbose --append --logfile=/var/log/vdsm/upgrade.log upgrade-unified-persistence (code=exited, status=0/SUCCESS) Main PID: 19079 (code=exited, status=1/FAILURE) Also, I upgraded to until 4.0 , but it seems to same. I cant reinstall, and reactivate the host. Originally it was an AIO installation. Please help me solve this problem. Thanks in advance, R Tibor