So ill ask here and see what sort of answer i get. Or at least point me in the right direction. I have a server here, sitting quite comfortably on ubuntu 18.04 LTS got a heap of drives in it that have ZoL and its just a backup server i turn it on run an rsync then shut it down. It's way over powered for its job, but i got them cheap a long time ago. It's a duel CPU supermicro X7Db3 with 2 E5430s or something like that., 20g of ram or there abouts. Got some HBA card sin there as well. Few generations old. Anyway i tried upgrading it to 20.04, and it didn't boot, since it runs headless i had no clue, finally attach a monitor. linux stalls booting, reads like it stalls waiting for hte CPU to finish something stuck for 15002 jiffies or something to that effect. It's kinda annoying as i have no way to copying the entire log since i don't get any interactivity. And things scroll past that might be important with no way of seeing them. Thought maybe the upgrade went messy, tried a live CD it also couldn't install or even run setup i can't remember. 18.04 installs and runs fine thou. Tried it in an identical server (i have 2 with same hardware) same problem of stalls. Now i've never really had a problem with ubuntu with old hardware it tends to just work, not sure if anything may have been depreciated or a default kernel option changed? I don't need it upgraded really, but i'd like to know why it doesn't work so at least a update won't break it. What sort of things would people look at, and turn on off? Troubleshooting it is a pain as need to plug in old monitor and sit on the cold concrete floor next to my rack... thoughts?