Realport devices sometimes disappear from server

I’ve got a Red Hat Enterprise Linux ES 5 server talking to Digi PortServer TS16’s using RealPort serial devices. It works fine for a while, I can run applications that communicate across the serial ports using the local device names like “/dev/ttyaa00” but once in a while - and I’m not sure why - the RealPort serial ports disappear from the server and then come back with ownership root:root and permissions 600 (rw for root, no one else can access).

Does anyone know under what circumstances the RealPort device nodes can disappear from the server? Or if there’s a log somewhere I can look at for diagnostics information?


Sounds like there may be something going on with UDEV. You may want to activate UDEV logging.

Also, looking over the /var/log/messages file may show more information.