Strange server/network problem

[Chopsy]

We run a Netware v4 server, and we've been suffering some strange problems. Most nights, at around 12:15am, the clients will show a "Client32 server not responding, press Enter to retry in the background" message. Sometimes it only lasts for a few seconds, sometimes a couple of hours. The server doesn't show anything in it's logs, and everything looks OK.

I've seen it do it during the day a couple of times, and have never been able to figure out what is happening. I've only just been made aware that it's been happening regularly at night. The night staff thought it was supposed to happen!

There's very little network traffic at night, and only a few PCs are running, so it doesn't seem to be a network problem. The only thing running on the server at that time of night is the ArcServe backup, but I can't figure out any reason why the backup would cause this problem.

Any suggestions greatly appreciated!

 

[JockMullin]

Hi, Chopsy

Well, something is causing the server not to communicate with the clients. Since it is all clients it is either a general network problem (like a hub or switch) or more likely something wrong with the server.

I have had a similar situations and it turned out to be the nic in the server going sour.

I assume there is nothing unusual in the Arcserve logs, such as rights or file access problems? Does the Arcserve sched coincide with the overnight events?

Are there any other servers on the network? Are they or their clients affected at all?

I also had this problem once when a W/S running McAfee anti-virus had been set up to do a complete scan overnight, including network drives. It was scanning a Novell folder with many thousands of files and every time the scan got to that folder the server was locked up for a good 10 mins.

Best regards
Jock

 

[onetime]

what is the stress on the server during these times? high cpu, mem and/or disk utilization? have you started logging these issue to determin if there is a trend?

 

[spi200]

Hi

Sounds like a network communication issue which will require some fault finding. May be caused by a single NIC or a bad Hub\Switch, anyway first check for errors in Monitor on the LAN card, CRC errors should be Zero - some of the other counters may also indicate a problem. You may need a utility to assist you in tracking down the problem - Netware offer a free tool called Lanilyzer ( not sure the spelling ) but I do no it only runs on 95\98 etc no NT.
If you have a bad NIC card or error on the LAN it will identify the offender. Otherwise there are better tools on the market, but they can cost you !!!
Don't discount the tips above - they sound like solid sugestion's to me.

Regards

David CNE


Regards

 

[thickage]

Sounds like your ARCserve backup and client are fighting for the same resources. Couple of things to try:

1. update your clients
2. check ARCserve log and see if there are specific files that are being backed up causing this issue
3. try changing the ARCserve jobs, making sure the "deny none" feature is listed; that way, if ARCserve is trying to backup a file that the client is using, the client takes preference

Good luck...