@PhilV thank you for your reply, hoping the best for you.
jacobwilliam: "A VM has access to practically the same Internet speed as the host PC; no more of a slowdown than going through a typical router." -> This should be the case of course, but this is not our case, and it seems there are many cases, all in Gravelines datacenter and it appears they have no idea at this time why is happening.
Since this Friday, no news in my case.
@PhilV i can confirm that if they make test in rescue will work well for them. The issue (i am 99% sure) is when we are forced to use vmac on virtual machines to get working with bridge. Here comes the bad.
"When starting VM, network is full speed equal to host... after few minutes, download fall down." -> Exactly the same case of me.
This was my iperf test on VM:
iperf -c iperf.ovh.net -i 2 -t 10 -r
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 85.3 KByte (default)
------------------------------------------------------------
------------------------------------------------------------
Client connecting to iperf.ovh.net, TCP port 5001
TCP window size: 196 KByte (default)
------------------------------------------------------------
[ 5] local 13*.**.**.** port 34635 connected with 188.165.12.136 port 5001
[ ID] Interval Transfer Bandwidth
[ 5] 0.0- 2.0 sec 219 MBytes 919 Mbits/sec
[ 5] 2.0- 4.0 sec 225 MBytes 942 Mbits/sec
[ 5] 4.0- 6.0 sec 225 MBytes 943 Mbits/sec
[ 5] 6.0- 8.0 sec 224 MBytes 939 Mbits/sec
[ 5] 8.0-10.0 sec 225 MBytes 944 Mbits/sec
[ 5] 0.0-10.0 sec 1.09 GBytes 937 Mbits/sec
[ 4] local 13*.**.**.** port 5001 connected with 188.165.12.136 port 43838
[ 4] 0.0- 2.0 sec 2.09 MBytes 8.75 Mbits/sec
[ 4] 2.0- 4.0 sec 1.57 MBytes 6.60 Mbits/sec
[ 4] 4.0- 6.0 sec 1.51 MBytes 6.34 Mbits/sec
[ 4] 6.0- 8.0 sec 2.19 MBytes 9.19 Mbits/sec
[ 4] 8.0-10.0 sec 1.52 MBytes 6.39 Mbits/sec
[ 4] 0.0-10.5 sec 9.12 MBytes 7.31 Mbits/sec
Not good.
@PhilV If you want, suggest then that they make test -in rescue mode- but setting/unsetting the vmac on the same IP. Of course i had notified of this, all my test and no response, and i was unable to get working in rescue a subnet IP with the vmac assigned.
While in rescue mode, it appears okay. Of course the additional IP i used for test was without vmac, and this is the reason the IP was stable and full speed.
So, all points to (supposed/i want to think) unintentionally the bw is being limited via vmac. In the case in one VM has multiple IP -sharing vmac- the total "limited" bw is divided for each IP, so bw is very very worst in this cases.
As previously comment
@d1ch0t in his case, they refund and he goes to RBX where it is supposed he don´t have the problem.
So no very good news, since they appears that they not find -or do not share, or do not assume- the root issue. But yes, is happening in GRA.
I can´t put this server in production and we can´t assume this.
I´ll keep updated post. Good luck! Greetings!