Ceph provides a script to generate a graph for the peering state machine, which is super helpful to study the state transitions of placement groups. To generate the graph, here are the commands: This is the latest SVG file I generated from the source as of this writing: There would be a lot to learn
In Linux, each PCI device is associated with a 2-byte vendor ID. Here is an example: To decode the ID to be the name of the vendor, we need mapping information between the ID and the name. lspci uses the PCI ID repository that can be downloaded/browered from http://pci-ids.ucw.cz/. We can use strace to evidence