how to connect two ESXi hosts with a 1Gbit link via cross-over and transfer files between them?

[antongolubev]

Dear community,

As many of you I am facing the problem of performing an efficient backup of VMs. Unfortunately I cannot use standard methods: my servers are rented root servers and haver therefore some limitations. Their main NIC is attached to the Internet on the speed of 100Mb. It is very slow if I try to backup VM images via this connection. Moreover backup sessions running through shared management interface are affecting the performance of productive virtual machine.

To solve this problem I ordered an extra network cards to each server and asked the datacenter to connect my themwith a physical link (cross-over cable). Ok, the 1Gbit link between my servers is established, but how to utilize it now?

- I cannot move the management interface to those NICs, since they don't have connection to the internet.

- I cannot use them from one of guest machines because the guest machine cannot access disk files on the host.

So I exhausted all my ideas. May be somebody knows the trick which will allow me utilizing 1Gb link between two ESXi machines for mutually backing up disks of virtual machines from one host to another.

Thank you for your ideas in advance.

King regards,

Anton

[admin · Accepted solution]

Create a vSwitch on each host and attach the NIC you are going to use with the x-over cable.

Create a Service Console portgroup on each vSwitch and assign it an IP address in the same subnet for each server (router/gateway address not needed) e.g. 192.168.0.1 and 192.168.0.2 on each host.

Connect the crossover cables between the server NICs.

You should have a connection between the two service consoles. I would now download and deploy the vMA appliance, on both hosts for fault tolerance. Write a script on the vMA on each host to do a vmkfstools -i <source.vmdk> <destination.vmdk> from one host to the other, and vice-versa.

If you have VMs registered pointing at these VMDKs on both hosts, then have your scripts delete the VMDKs and re-clone them using vmfkstools each time you backup, you should have a rudimentary (Full copy) VM backup solution in place.

Now don't you miss the service console?

Good luck,

Alex

www.phdvirtual.com

[J1mbo]

As a point of interest crossover cables aren't required for GbE.

http://blog.peacon.co.uk

Please award points to any useful answer.

[antongolubev]

Hi Alex,

Thank you for your helpful answer. I was able to establish the connection between two Hypervisers via 1Gbit-link. Now the transfer rate has increased from 5Mb to 15Mb, when using scp via the fast connection. But you have mentioned that vmkfstools can be used to transfer the files between host. Could you please give a syntax example? I believe that the file transfer via non-scp tool can be more efficient, because we skip an expansive encoding-decoding step.

Kind regards,

Anton