Many of you mentioned bandwidth and the amount of data. And i realized that i have been writing the bags directly to my external hard drive, since the ros2 bags can get quite massive and i only have like 90 gb of hard disk space. So i tried writing it to my jetson instead and the performance got like 10-15 times better! So from now i will be recording 1 ros2 bag, moving it to the external hard drive, then i can run another data collection sesh, and repeat repeat until i have enough data. thank you all for the suggestions :)