Running DB2 agent level backup, backup size is about 1.9TB. Four tablespace, one tablespace is about 1.2TB. First hour backup performance is good(about 250Mbps), Commvault is backing up the 4 tablespace in parallel. From 2nd hour, Commvault only backup the huge tablespace, backup performance is only 100Mbps with one session.
How to backup one tablespace with multiple session? or any other way to improve backup performance?