I was going to pose a question, but then I found the answer; however, it is so strange, that I'll write it up for comments. O:-) Suddenly, yesterday, my cpu ussage went up to 100% all the time, and I was not doing any thing, nor was it a cron job. 2:16am up 3:46, 20 users, load average: 2.21, 2.19, 2.56 123 processes: 117 sleeping, 5 running, 1 zombie, 0 stopped CPU states: 5.7% user, 94.2% system, 0.0% nice, 0.0% idle Mem: 255908K av, 251448K used, 4460K free, 0K shrd, 84688K buff Swap: 2080336K av, 78380K used, 2001956K free 30496K cached PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME COMMAND 1 root 25 0 88 76 52 R 19.9 0.0 44:15 init 2 root 25 0 0 0 0 SW 3.7 0.0 8:35 keventd Notice the 0.0 idle, 94.2% system, and init using 19.9% CPU. This situation survived "init 1" or a reboot with power cycle. Even the rescue system (CD) had the same symptom, but not suse 7.3 which I have in another partition. So, I was going to ask you if this was normal, ideas, etc. I powered off and left. For some reason I came back and noticed the external modem was still on. Could it be... :-? I couldn't resist, and powered on again, but first I switched off the modem: And yes, the system was back to normal: 3:10am up 11 min, 3 users, load average: 0.00, 0.07, 0.07 83 processes: 81 sleeping, 2 running, 0 zombie, 0 stopped CPU states: 1.7% user, 0.3% system, 0.0% nice, 97.8% idle Mem: 255908K av, 209704K used, 46204K free, 0K shrd, 34628K buff Swap: 2080336K av, 0K used, 2080336K free 81076K cached PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME COMMAND 1987 root 15 0 271M 14M 6136 S 0.5 5.9 0:02 X 2027 root 15 0 932 932 720 S 0.3 0.3 0:01 top 2178 cer 15 0 6576 6572 5212 S 0.3 2.5 0:00 metacity ¿HOW? ¿What can the modem do, that the system gets so busy? ¿Interrupts? Well... I did a cat /proc/interrupts, and yes, I noticed that one of them (acpi) was increasing rapidly, much faster than the timer or any of them (6 figures, and increasing the count by thousands every time I checked). After switching off the modem, it only had a value of 41. cer@nimrodel:~> cat /proc/interrupts CPU0 0: 80114 XT-PIC timer 1: 3609 XT-PIC keyboard 2: 0 XT-PIC cascade 5: 59072 XT-PIC nvidia 8: 2 XT-PIC rtc 9: 41 XT-PIC acpi 11: 6 XT-PIC usb-uhci, usb-uhci, Intel 82801BA-ICH2, eth0, bttv 12: 5218 XT-PIC PS/2 Mouse 14: 11044 XT-PIC ide0 15: 143 XT-PIC ide1 NMI: 0 LOC: 0 ERR: 0 MIS: 0 Interesting... Today, I checked again: acpi interupts was 0. I power cycle the modem, and I get 5721 interrupts, and remains there. Why so many? By the way, this happened to me months ago, but I had forgotten. I noticed once when swithing form linux to windows that windows could not start. After re-installing windows - what else ;-) - , it turned out that it was that da***d modem. Well, at least, linux continued running :-) Just for the record, the modem is an external, serial port, 3Com US Robotics 56K. ¿Has anything like this happened to you? Why was init hit so badly, as my inittab do not have modem entries? Can it be prevented? -- Cheers, Carlos Robinson