To view the PHP web server logs on a Palo

tail follow yes mp-log php.debug.log

To view the VPN logs on a Palo

tail follow yes mp-log ikemgr.log

See here. Show firewall logging rate

debug log-receiver statistics

Show Panorama logging rate. On Panorama, you can see this in the GUI using the Statistics link under Panorama > Managed Collectors.

debug log-collector log-collection-stats show incoming-logs