Netbackup 7.01 VMware Snapshots using SAN transfer type - still network traffic?

[jbiggley]

I'm trying to use Netbackup 7.01 to perform VMware snapshot backups using the vStorage API from a vSphere 4 environment.  I've configured the off-host backups to a media server (not the master server) using the SAN transfer type.  In spite of that, I am still seeing some data on the copper links during backups.  On a recent 110GB snapshot transfer to FC attached LTO3 drives I still saw about 5GB worth of traffic from the off-host server to the master server.

I'm going to throw a packet sniffer on the connection and perform some testing, but I wanted to know if anyone else had run into this problem, or if someone could explain why I was still seeing this traffic?  The traffic is short and fast, it fully saturates my gigabit copper connections, but only lasts for about 40 seconds or so.

Any thoughts would be greatly appreciated!  I'll let everyone what kind of traffic I see.

[Giroevolver]

If you are running it to a media server that is not the master there will be some traffic sent to the master server as it will be catalog infomation (more so if your using full mapped VM). Not sure that there should be 5GB worth in one 5GB burst though. I will run a test on my environment and see if i get any traffic.

[jbiggley]

Perfect!  I didn't even think of the catalogue traffic being the cause.  To clarify, the traffic is not in a single burst, but does happen fairly quickly.  And yes, I am using fully mapped VMs.

[VirtualED · Accepted solution]

The bpbrm from the media server sends the catalog information to the bpdbm on the master server usually after receiving a certain amount of information.  I am not sure if it is a number of files or just a size.  But it should definitely explain what is being sent to the Master.  You probable will also see other communications to the master/EMM server.  As the media server needs to keep let the master server know its current status.

[Giroevolver]

I also see some traffic passed over to the master which is the catalog info so I guess that answers your question :)

Please mark the solution

[jbiggley]

Thanks all!  We'll definitely have to re-think our network layout to ensure that this traffic doesn't impact production traffic at all, not that it is alot of data, but I like to keep backup data with the backups for sure.  Either way, you've freed me from a problem that has been nagging me for a couple of months now.

Kudos.