Slow DB2 DB Backups / Fast Log Backups

Hi Douglas,

thanks for the reply.

Sned /recieve:

 tcp_recvspace = 16384
 tcp_sendspace = 16384

But I think my problem is not the network part, tht DB Backups go to SAN connectect tape drives.

I think I might have one of 2 bottlenecks, or both!

1. the configuration of the LTO5 drives in AIX is incorrect

Could not find much here, Symantec& IBM say: Install atape, enable variable buffer in smitty and you are ready to go.

2. some sort of buffer setting, may it be in AIX or in NBU is wrong.

The only thing I'm ablte to find regarding buffers is NUMBER_DATA_BUFFERS/SIZE_DATA_BUFFERS

When I look at the output of such a slow backup job I see this:

 Info bpbkar(pid=37814752) dbclient waited 470702 times for empty buffer, delayed 701816 times

As far as I know this means that NBU waits till the tapedrive has emptied the buffer? So the tape is the bottleneck?

Or can this mean that these buffers are to small so the LTO5 drive is strat/stop all the way causing these wait times?

How can I test the tape performance in AIX without NBU interferrence?

Volker