Log location:
/usr/local/avamarclient/var-proxy-x
2016-04-09 17:00:45 avvcbimage Info <0000>: Logging to /usr/local/avamarclient/var-proxy-8/Windows VMs-2000028812341-228c3603d60a5d988129677defb348da29645aeb-1017-vmimagew.log
If you see above file name is /usr/local/avamarclient/var-proxy-8/Windows VM-2000028812341-228c3603d60a5d988129677defb348da29645aeb-1017-vmimagew.log it contain info about Job ID
and which proxy is being used
For more information please refer to :
http://cormachogan.com/2014/03/03/where-to-look-when-troubleshooting-vdpvdpa-backup-issues/