Netbackup DDBoost/OST behavior

[chearn]

My understanding of Netbackup using DDBoost/OST to a DataDomain appliance is that the client being backed up should be able to directly write to the DataDomain appliance.  What I'm seeing, however, is that the client is passing it's data through the media server, and the media server is writing it to the DataDomain appliance.  This is causing performance to suffer, since most of my media servers only have a 1gig link & most will run a few backups at once.  Average throughput of a backup right now is ~8MB/s when writing to that DataDomain DDBoost storage unit.  I see a lot of data moving in & out of the media server during the backup process, which makes me come to this conclusion.  On the DataDomain admin webpage, I also do NOT see a connection from the client itself on the DDBoost page, but I DO see connections from the media servers using them.

My question is, is this behavior normal for Netbackup or should the client be making a direct connection to the DataDomain appliance?  If the client should be making a direct connection, is there a specific plugin we have to install on the clients to enable this?  If the client should NOT be making a direct connection, is it possible to activate a secondary gigabit link on the media server to where the data flowing in would come in on the existing link and the data going out would flow on the secondary one?

[nairaj]

Hi, Backups are taken through Media Servers. You can install the OST plugin on the media servers which can talk to the DataDomain. DDBoost needs to be enabled on the DataDomain. Also, if you have multiple network interfaces on the DD, you can configure DDboost ifgroups to achieve good speed and redudency at the sametime. 2cents from me..

[chearn]

I guess the issue there is if the data is going into & out of the media server on the same interface, it cuts the bandwidth in half.  If the media server has two network interfaces, would it be possible to tell the traffic to come in on one interface & go out the other?

[Yasuhisa_Ishika · Accepted solution]

It is normal. Clients can not write data directly to DD. Only the hosts which have media server role with OST plugin can write data to DD. This includes common media server covered by  Entetprise Server license and SAN media server covered by Enterprise Client license.

 is it possible to activate a secondary gigabit link on the media server to where the data flowing in would come in on the existing link and the data going out would flow on the secondary one?

It is possible by configuring 2nd NIC on other subnet(say storage subnet) and move DD into storage subnet.But this requires large reconfiguration tasks like network recabling, (sometimes)physical movement, name resolver change.

Why don't you consider to configure avtive-active IPMP with 2 NICs before?

[Yasuhisa_Ishika]

Traffic flow is decided by host OS following its IP configuration. There are no special mechanism in NetBackup to control data flow. You need to manage this at OS level, so as I wrote, you need to configure storage subnet and move DD onto it.

[chearn]

I guess IPMP would help too... about the same, right?

[Yasuhisa_Ishika]

Well, while I mentioned IPMP, Link Aggregation is better choice for performance improvement.
With Link Aggregation, you can aggregate multiple NICs into logical single NIC.

http://docs.oracle.com/cd/E19082-01/819-6990/gfxno/index.html

IPMP and Link Aggregation does not work as you expected. These technology may improve performance by load balancing(IPMP load balancing is limited), but you can not assign diffrenet role for each NIC. If you want to use one NIC for incomming backup streams and another to outbound ddboost streams, you need to reconfigure network as I wrote before.