Tuesday, 3 May 2016

VDP Backup With External Proxy

So in the previous article we saw the types of backup protocol used by VDP. We saw that when the ESXi host which is hosting the VDP appliance does not have the access to the datastore of the VM it is backing up, then the backup protocol used is Network Block Device (NBD). One way to avoid NBD is to bring the VM on to a storage which is seen by the ESXi host hosting the VDP appliance. The other method is to deploy an external proxy for the VDP appliance onto the host which is hosting the client that needs to be backed up. Please note, that once you deploy external proxy, the internal proxy will be disabled automatically. 

To add external proxy in detail, you can visit this link here.

From the below screenshot you can see that the external proxy is deployed on the host where the client that requires to be backed up resides. 


This will create a virtual machine for the proxy on the specified host.

Now, ideally, when I run the backup for this client without external proxy, it should work with the NBD protocol. However, now the proxy where the avAgent runs, can see the datastore of the client virtual machine, it will proceed with the Hot-Add protocol. 

Since avAgent runs on the proxy which talks to the MCS, the disk will not be mounted on the VDP appliance, instead it will be mounted on the external proxy virtual machine. You can see this from the below screenshot. 


vdp_ba_vma41 is the proxy virtual machine, and the client being backed up is CentOS7 and we can see the virtual disk of client is mounted on the external proxy virtual machine. 

Well, that's one of the use case of deploying external proxy.