What is pseudo saveset?

Hello,

 

We have NetWorker 9.2 running Exchange 2016 log backups to DD990.

Log backup of every DB is running OK but pseudo saveset job fails.

 

I searched admin and exchange guides and no luck. Googled it. Found this article - http://intelligentsystemsmonitoring.com/community/dell-community/pseudo_saveset-or-aggregated-save-model-in-networker-9/ 

But it still unclear for me. 

Could someone please explain what is pseudo saveset? Or please point me to correct guide (or I missed something).

 

Regards, Yuri.