I have an older Macbook Pro and my Lightroom application is slow to come up. I think it may be waiting on the USB attached disk, but I'd like to observe the aggregate and real-time waits it's doing on disk reads/writes (such as a time-based graph of the size of the disk op wait queues). My catalog has just over 100K images. I've tried the following:
Activity Monitor - only shows aggregate bytes read/written
iosnoop and fs_usage - only shows traces of individual disk ops
Disk Utility - only shows space usage
Disk Inventory X - only show space usage
The Activity Monitor does show the real-time CPU usage, and that's only 20% for my Lightroom application, so I don't think it's limited by the CPU.
I have to believe that such a monitoring tool exists, but Google search can not seem to find it using the keywords I've tried. Any insights would be greatly appreciated.