RE: Parallel saves: Splitting a library also

Rob,

Check the Backup, Recovery, and Media Services for I, Chapter 7 - Tailoring Your Backup - Sample Backup Scenarios: Working with Multiple Control Groups and Shared Devices



Figure 9. Multiple control groups in a concurrent save

Suppose that the FINHST library in the FINANCE group contains 50 small objects and 4 very large
objects. At this point, you want to save the FINANCE group to TAP01. Your main concern at this point is
to balance the backup window for both tape drives. For example, the size of the objects in the FINHST
library might force TAP01 to process longer than TAP02. Thus, the control group processing would not
end concurrently. To remedy this, you can split the FINHST library into two control groups of
approximately 25 small objects and 2 large objects each, as shown in Figure 10. By doing so, you can
better balance the save window for both devices.

Paul



-----Original Message-----
From: MIDRANGE-L [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Rob Berendt
Sent: Thursday, June 23, 2016 1:31 PM
To: midrange-l@xxxxxxxxxxxx
Subject: Parallel saves: Splitting a library also

We're doing parallel saves now. So we tell BRMS to use 4 drives on it's saves and get cranking.
It's kind of like putting a list of your libraries into a data queue. And then having four data queue readers (one for each drive) reading the data queue and then doing a SAVLIB to that drive. Before IBM i had parallel saves I actually wrote something like this. I sorted mine by library size descending.

Anyway, what I am finding is that I have this one inordinately huge library. In fact, all the the other libraries together do not come close to the size of this one library. This library takes 49% of our disk and
spans three tape volumes. The objects within that library are similarly
sized. So it's not like there's one big object and many tiny objects.
Should be a good distribution.

Is there some way in BRMS to tell it to parallel save the OBJECTS within that library?

Do I have to figure out a way (in BRMS) to omit that library from *ALLUSR and save it with some BRMS equivalent of SAVOBJ within that control group?
And then maybe the SAVOBJ would parallel span volumes?


Rob Berendt