I cannot do the update by VC only from VCSU (from what I understand) so I do not understand your question.
What log ? There is no log for this as far as I am aware, It only stops when I shutdown VCSU.
EDIT : Here is me trying to do a Healthcheck after the update froze :
[Thu Jul 13 11:00:19 2017]
[Thu Jul 13 11:00:19 2017] -------------------------------------------------------------------------------
[Thu Jul 13 11:00:19 2017] HPE BladeSystem c-Class Virtual Connect Support Utility
[Thu Jul 13 11:00:19 2017] Version 1.13.0 (Build 10)
[Thu Jul 13 11:00:19 2017] Build Date: Apr 11 2017 12:20:40
[Thu Jul 13 11:00:19 2017] Copyright (C) 2006-2017 Hewlett Packard Enterprise Development LP
[Thu Jul 13 11:00:19 2017] All Rights Reserved
[Thu Jul 13 11:00:19 2017] -------------------------------------------------------------------------------
[Thu Jul 13 11:00:19 2017]
[Thu Jul 13 11:00:19 2017] Initializing, please wait... [Step 1 of 2]
[Thu Jul 13 11:00:36 2017] ERROR: Invalid IP address
[Thu Jul 13 11:00:36 2017]
[Thu Jul 13 11:00:36 2017] Total execution time: 00:00:17
[Thu Jul 13 11:00:36 2017]
[Thu Jul 13 11:00:36 2017] VCSU log file is available at the following location:
[Thu Jul 13 11:00:36 2017] C:\Users\demotest\AppData\Local\Temp\vcsu-2536.log[Thu Jul 13 11:00:19 2017] (2108)[VcsuInit.cpp:458] : VCSU Library Version: 1.13.0.10
[Thu Jul 13 11:00:19 2017] (2108)[VcsuInit.cpp:358] : User does not have Administrator privilege
[Thu Jul 13 11:00:36 2017] (2108)[LocalIp.cpp:92] : Failed to connect, errno = 13
[Thu Jul 13 11:00:36 2017] (2108)[AuthenticateTarget.cpp:60] : Unable to communicate with given IP 192.168.1.129
[Thu Jul 13 11:00:36 2017] (2108)[AuthenticateUser.cpp:56] : Authentication failed
[Thu Jul 13 11:00:36 2017] (2108)[Initialize.cpp:175] : Cleanup failed for one or more reasons
Here is the standby :
[Thu Jul 13 11:01:54 2017]
[Thu Jul 13 11:01:54 2017] -------------------------------------------------------------------------------
[Thu Jul 13 11:01:54 2017] HPE BladeSystem c-Class Virtual Connect Support Utility
[Thu Jul 13 11:01:54 2017] Version 1.13.0 (Build 10)
[Thu Jul 13 11:01:54 2017] Build Date: Apr 11 2017 12:20:40
[Thu Jul 13 11:01:54 2017] Copyright (C) 2006-2017 Hewlett Packard Enterprise Development LP
[Thu Jul 13 11:01:54 2017] All Rights Reserved
[Thu Jul 13 11:01:54 2017] -------------------------------------------------------------------------------
[Thu Jul 13 11:01:54 2017]
[Thu Jul 13 11:01:54 2017] Initializing, please wait... [Step 1 of 2]
[Thu Jul 13 11:01:57 2017] ERROR: Specified OA is not primary
[Thu Jul 13 11:01:57 2017]
[Thu Jul 13 11:01:57 2017] Total execution time: 00:00:03
[Thu Jul 13 11:01:57 2017]
[Thu Jul 13 11:01:57 2017] VCSU log file is available at the following location:
[Thu Jul 13 11:01:57 2017] C:\Users\demotest\AppData\Local\Temp\vcsu-368.log[Thu Jul 13 11:01:54 2017] (2900)[VcsuInit.cpp:458] : VCSU Library Version: 1.13.0.10
[Thu Jul 13 11:01:54 2017] (2900)[VcsuInit.cpp:358] : User does not have Administrator privilege
[Thu Jul 13 11:01:55 2017] (2900)[GetRemoteEndpointInfo.cpp:91] : OA found at 192.168.1.123 with version 4.60
[Thu Jul 13 11:01:56 2017] (2900)[VcsuCore.cpp:392] : Target name:
[Thu Jul 13 11:01:56 2017] (2900)[OaWrap.cpp:823] : OA IP Address:192.168.1.123
[Thu Jul 13 11:01:56 2017] (2900)[OaWrap.cpp:829] : OA1 IP Address:192.168.1.123
[Thu Jul 13 11:01:56 2017] (2900)[VcsuInit.cpp:579] : [] OA Version: 4.60
[Thu Jul 13 11:01:57 2017] (2900)[OaWrap.cpp:443] : Onboard Administrator Role: Standby
[Thu Jul 13 11:01:57 2017] (2900)[VcsuCore.cpp:189] : Specified Onboard Administrator is not primary
[Thu Jul 13 11:01:57 2017] (2900)[VcsuInit.cpp:589] : [] Failed to validate OA state
[Thu Jul 13 11:01:57 2017] (2900)[VcsuInit.cpp:675] : vcsuInitOA failed
[Thu Jul 13 11:01:57 2017] (2900)[AuthenticateTarget.cpp:91] : authenticateOA failed
[Thu Jul 13 11:01:57 2017] (2900)[AuthenticateUser.cpp:56] : Authentication failed