Hi. I'm sorry you're having trouble. Unfortunately, it isn't clear from your post what hardware and software you're running. And while I may not be able to solve your problem, I can't provide any insights into possible root causes, solutions, or circumventions without more information. The questions that immediately come to mind are:
- What version/flavor of OpenBSD are you running?
- What architecture are you using?
- What NIC hardware is in use?
- Which ftp client are you using from the shell? The built-in ftp(1)?
- If the external storage is NAS-attached as described, why are you using FTP instead of NFS or SMB/CIFS?
- Have you set the ddb.console sysctl to permit keyboard entry into ddb(4) during a hang? If so, when in a console rather than X, have you been able to enter ddb with the keyboard sequence that is applicable to your architecture?
- Have you inspected /var/log/messages for any possible hints in logged messages about the problem, such as exhausting mbufs?
- Have you run netstat(8) with the -m, -i, or -s options during transfers to watch for network related problems as the transfers are in progress?
A dmesg would answer the first three questions.