I think I set the record for the slowest successful boot today. I was doing four or five test installations on different machines and did one to an external USB disk (20 GB IDE disk in a USB 2.0 highspeed enclosure). It didn't boot (couldn't find the root filesystem, whether on an LV or partition), so I started that system in rescue mode, chrooted to /mnt/sysimage, and then ran a 'yum update' to see if the latest rawhide would boot.
The boot started, but the system stuck right after the "usb-storage: device scan complete" message. I was busy with the other systems so I just left it running in case it would eventually timeout and continue. Messages of the form "was: XXX sb: XXX now: XXX" appeared every 20-30 minutes (where XXX was a long number with lots of decimals), and after about 2 hours 15 minutes the system continued with the boot process (!). Once the system was running, it performed normally and performance was quite good.
I thought I had missed something and/or was going crazy so I repeated it on another machine of similar specs. (Even Multics booted in less time than this :-)
I filed BZ202554 against mkinitrd for lack of a better suspect. Has anyone else encountered this behaviour?
-- Chris Tyler