slow sharepoint backup

Hello

I have an issue with a Sharepoint GRT backup with NBU 7.6.1.2.

The architecture is the following :

- Sharepoint 2010, 2 Front web servers, 2 application servers, 1 Clustered SQL Server

- all servers are virtual machines

- Service account used for legacy Network, legacy client and client services is domain admin + local admin and has the required 4 rights in local security policy

- DNS is OK (hosts has been also updated with short and long names - just in case)

- non-GRT backup is runing fine

- GRT backup is starting well, but after "some time" is slowing down ...

- I have enabled verbose loging on SQL server and the following messages appear in bpkar log file :

21:54:06.290 [1708.7048] <2> vnet_sortaddrs: [vnet_addrinfo.c:3852] sorted addrs: 1 0x1
21:54:06.290 [1708.7048] <2> vnet_get_pref_netconnection: [vnet_addrinfo.c:4750] using interface ANY
21:54:06.290 [1708.7048] <2> vnet_sortaddrs: [vnet_addrinfo.c:3852] sorted addrs: 1 0x1
21:54:06.290 [1708.7048] <2> vnet_get_pref_netconnection: [vnet_addrinfo.c:4750] using interface ANY
21:54:06.290 [1708.7048] <8> vnet_cached_getaddrinfo_and_update: [vnet_addrinfo.c:1544] in failed cache ERR=10109 NAME=SVBLL-WI05Q SVC=bpspsserver
21:54:06.290 [1708.7048] <8> vnet_cached_getaddrinfo: [vnet_addrinfo.c:1267] vnet_cached_getaddrinfo_and_update() failed 6 0x6
21:54:06.290 [1708.7048] <8> init_remote_connect_recs: [vnet_connect.c:949] vnet_cached_getaddrinfo() failed, status=6, OS ret=10109, host=SVBLL-WI05Q, service=bpspsserver
21:54:06.290 [1708.7048] <2> vnet_sortaddrs: [vnet_addrinfo.c:3852] sorted addrs: 0 0x0
21:54:06.290 [1708.7048] <8> init_connect_recs: [vnet_connect.c:868] init_remote_connect_recs() failed 6 0x6
21:54:06.290 [1708.7048] <2> init_connect_recs: [vnet_connect.c:880] Ignoring some failures. Success count 2 0x2
21:54:06.290 [1708.7048] <2> async_connect: [vnet_connect.c:1499] connect in progress 1 0x1
21:54:06.304 [1708.7048] <2> vnet_pbxConnect: pbxConnectEx Succeeded
21:54:15.974 [1708.7048] <8> vnet_vnetd_service_socket: [vnet_vnetd.c:1995] VN_REQUEST_SERVICE_SOCKET 6 0x6
21:54:15.974 [1708.7048] <8> vnet_vnetd_service_socket: [vnet_vnetd.c:2009] service bpspsserver
21:54:16.484 [1708.7048] <2> do_pbx_service: [vnet_connect.c:2159] via PBX/via VNETD bpspsserver CONNECT FROM 10.225.64.101.64646 TO 10.225.64.106.1556 fd = 1280
21:54:16.485 [1708.7048] <2> async_connect: [vnet_connect.c:1691] connect async CONNECT FROM 10.225.64.101.64646 TO 10.225.64.106.1556 fd = 1280
21:54:16.485 [1708.7048] <2> connect_to_service: connect succeeded STATUS (0) SUCCESS FROM 0.0.0.0 TO SVBLL-WI05Q 10.225.64.106 bpspsserver VIA pbx
21:54:16.485 [1708-7048] vnetdSendRequest   Sending message 0xf331
21:54:16.485 [1708-7048] vnetdProcessMessage   received a reply successfully for message 0xf331
21:54:20.175 [1708.7072] <2> vnet_sortaddrs: [vnet_addrinfo.c:3852] sorted addrs: 1 0x1
21:54:20.175 [1708.7072] <2> vnet_get_pref_netconnection: [vnet_addrinfo.c:4750] using interface ANY
21:54:20.175 [1708.7072] <2> vnet_sortaddrs: [vnet_addrinfo.c:3852] sorted addrs: 1 0x1
21:54:20.175 [1708.7072] <2> vnet_get_pref_netconnection: [vnet_addrinfo.c:4750] using interface ANY
21:54:20.176 [1708.7072] <8> vnet_cached_getaddrinfo_and_update: [vnet_addrinfo.c:1544] in failed cache ERR=10109 NAME=SVBLL-WI05Q SVC=bpspsserver
21:54:20.176 [1708.7072] <8> vnet_cached_getaddrinfo: [vnet_addrinfo.c:1267] vnet_cached_getaddrinfo_and_update() failed 6 0x6
21:54:20.176 [1708.7072] <8> init_remote_connect_recs: [vnet_connect.c:949] vnet_cached_getaddrinfo() failed, status=6, OS ret=10109, host=SVBLL-WI05Q, service=bpspsserver
21:54:20.176 [1708.7072] <2> vnet_sortaddrs: [vnet_addrinfo.c:3852] sorted addrs: 0 0x0
21:54:20.176 [1708.7072] <8> init_connect_recs: [vnet_connect.c:868] init_remote_connect_recs() failed 6 0x6
21:54:20.176 [1708.7072] <2> init_connect_recs: [vnet_connect.c:880] Ignoring some failures. Success count 2 0x2
21:54:20.176 [1708.7072] <2> async_connect: [vnet_connect.c:1499] connect in progress 1 0x1
21:54:20.190 [1708.7072] <2> vnet_pbxConnect: pbxConnectEx Succeeded
21:54:24.119 [1708.7072] <8> vnet_vnetd_service_socket: [vnet_vnetd.c:1995] VN_REQUEST_SERVICE_SOCKET 6 0x6
21:54:24.119 [1708.7072] <8> vnet_vnetd_service_socket: [vnet_vnetd.c:2009] service bpspsserver
21:54:24.725 [1708.7072] <2> do_pbx_service: [vnet_connect.c:2159] via PBX/via VNETD bpspsserver CONNECT FROM 10.225.64.101.64653 TO 10.225.64.106.1556 fd = 1280
21:54:24.725 [1708.7072] <2> async_connect: [vnet_connect.c:1691] connect async CONNECT FROM 10.225.64.101.64653 TO 10.225.64.106.1556 fd = 1280
21:54:24.725 [1708.7072] <2> connect_to_service: connect succeeded STATUS (0) SUCCESS FROM 0.0.0.0 TO SVBLL-WI05Q 10.225.64.106 bpspsserver VIA pbx
21:54:24.726 [1708-7072] vnetdSendRequest   Sending message 0xf331
21:54:24.726 [1708-7072] vnetdProcessMessage   received a reply successfully for message 0xf331