Hello!

I have a problem from time to time with USB communication between my Dell PowerEdge 3250 server and UPS APC Smart 3000 Rack. Normally the communication works fine, but fromtime to time something hangs. The operating system is RedHat 2.1 AS ia64 (itanium 64bit). Normally I can see the UPS by appplying OS command

cat /proc/bus/usb/devices

Unfortunately from time I can't see it there. Another thing is that in my

/var/log/messages

file I can see many messages like this:

Aug 22 05:55:20 zeus kernel: usb_control/bulk_msg: timeout
Aug 22 05:55:52 zeus last message repeated 8 times
Aug 22 05:57:24 zeus last message repeated 8 times
Aug 22 05:59:28 zeus last message repeated 16 times
Aug 22 06:01:32 zeus last message repeated 16 times
Aug 22 06:03:36 zeus last message repeated 16 times
Aug 22 06:05:40 zeus last message repeated 16 times
Aug 22 06:07:44 zeus last message repeated 16 times
Aug 22 06:09:48 zeus last message repeated 16 times
Aug 22 06:11:52 zeus last message repeated 16 times
Aug 22 06:13:56 zeus last message repeated 16 times

I use apcupsd 3.10.17 UPS control software (the only one possible for RedHat ia64), but it deosn't apply to this problem. I mean it doesn't matter whether the software is running or not. Ofcourse if UPS is not seen by the OS, the doftware also doesn't work.

Restarting the server (without cutting off the mains - just warm reboot) doesn't work. After restarting, I have a lots of this timeout messages. The only solution is to detach USB cable from server and attach it againg. Then I can see the UPS among other USB devices again and there's also less messages about timeout. I must also admit that during normal work there are also messages, but they appear only few times per day.

Please, give me some words of advice.