Hello! I've noticed this problem two times now.. last time I fixed it by rebooting the (centos 5.1 x86 32b) xen host/dom0. Symptoms: - Already running domUs (debian 2.6.18-6-xen-686 32b PAE) continue running and working OK - Cannot start new domUs (debian 2.6.18-6-xen-686).. kernel bootup just hangs before running initrd. Same domU with the exact same xen domU cfgfile worked earlier. - This problem starts to happen after a "longer" uptime.. atm uptime for the dom0-host is 174 days. Cannot say what the actual "limit" is.. last time I used the dom0 everything worked fine, now it doesn't.. "xm list" shows the domain as "-b----" and the Time(s) for the domain does not increase.. it stays at 1.9 or so. It might increase to 2.0 after 15 mins or so.. it looks like nothing happens in domU kernel. "xm console" shows the bootup has stalled.. destroying the domU and restarting it might show the hang in a bit different place (+- a couple of lines). It always hangs before actually executing initrd image. Example console output: checking if image is initramfs... it is Freeing initrd memory: 12028k freed Grant table initialized NET: Registered protocol family 16 SMP alternatives: switching to SMP code <hangs here, nothing happens anymore> Like said, it could be a couple of lines later or earlier where it hangs.. I tried changing the domU to use just a single vcpu.. doesn't help. I tried changing (lowering and increasing) the amount of memory.. didn't help either. Any ideas how to debug this? -- Pasi