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Re: Server hangs if i remove and reconnect the N/W cable.

 
PVNV  PRASAD
Occasional Contributor

Server hangs if i remove and reconnect the N/W cable.

Hi all,
K-460 Server hangs if i remove and reconnect the N/W cable. Its working as NFS client and almost 6 FSs are mounted on it. This prob i could see only on NFS client system only. Once if i remove N/W cable there wont be any prob and then if i reconnect it even console also will hang and i cant even ping to server. i hv to restart the Mac. Any ideas pls..?

regards
PRASAD PVNV
12 REPLIES 12
harry d brown jr
Honored Contributor

Re: Server hangs if i remove and reconnect the N/W cable.

Why would you want to remove and then reconnect the Network Cable?

Are you testing or writing code to detect a network failure? If so, then what version of HPux do you have, and have you applied all of the current network and NFS patches? Also, what version of the firmware do you have? What type of network card are you using in your K460?
Live Free or Die
PVNV  PRASAD
Occasional Contributor

Re: Server hangs if i remove and reconnect the N/W cable.

HP-UX 10.20 with JUN'2001 CR patches/HP-PB 100 Base TX card

Actually our switch was down Y'day and then we just restarted the switch. There i could c server was hanging. Then i removed cable and reconnected and found the prob again.

Re: Server hangs if i remove and reconnect the N/W cable.

NFS is a kernel service, so losing NFS mounts will cause processes to hang in the kernel... of course, other processes should remain untouched (such as your getty process for your console) so you should still be able to log in at the console, unless parts of the OS are over the NFS mounts. What areas do you have NFS mounted? Can you provide us with a bdf output for when the system is working?

I am an HPE Employee
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Angus Crome
Honored Contributor

Re: Server hangs if i remove and reconnect the N/W cable.

We have two K-class servers that behave this way (a 460 and a 210). They both have sister machines which are running 11.00 and do not exhibit this behavior. However, I also think they are at differing firmware revisions. If this is still un-resolved, I will post the revision levels of all the pertinent boxes when I have a chance to check them.

One other possibility is that hostname resolution is messing up the machine. If the machine does a lot of lookups (web service), then it is possible that the queue time for resolution has buried the machine and it has become unusable. We generally try to put the files entry first in the nsswitch.conf so the box can always resolve its own name (even if the network has gone flaky).

Finally, there was an upgrade/recall for certain PB-100/BT cards a few years ago. The network processor would intermittently fail causing all kinds of problems. The HP-CE's generally showed up with replacement cards on a weekend and swapped the cards with the faulty processor (circa early 1999). Unfortunately, I no longer have the specifics for that problem.
There are 10 types of people in the world, those who understand binary and those who don't - Author Unknown
Angus Crome
Honored Contributor

Re: Server hangs if i remove and reconnect the N/W cable.

Just thought of one other thing;

Make sure your switch and card are set the same. I have seen a lack of auto_negotiate feature sometimes lockout a system when it can't determine and forces everything to 10/Half.
There are 10 types of people in the world, those who understand binary and those who don't - Author Unknown
Mike Botha
Occasional Contributor

Re: Server hangs if i remove and reconnect the N/W cable.

Check the port setting of your switch.
Most switches have a spanning tree algorithm that is used to prevent bridging loops on your network.
The switch port will go through listening, learning and then forwarding before forwarding traffic. This can take up to three minutes on some switches. This normally screws around network services to and from servers.
Check that spanning tree portfast in enabled on the switch port to the server. This will shorten the forwarding delay of the switch port.

Sundar_7
Honored Contributor

Re: Server hangs if i remove and reconnect the N/W cable.

Hi Prasad,,

While mouting the NFS try using the options
to try the mounting in the back ground also for giving up retrying after certain amount of time.

I dont exactly remember the options..U can try bgsoft or something like that.

Try man mount_nfs

Sundar

Learn What to do ,How to do and more importantly When to do ?
Sridhar Bhaskarla
Honored Contributor

Re: Server hangs if i remove and reconnect the N/W cable.

Prasad,

I have been having this problem on my K370 and K460 servers with HP-PB 100BTs. Once I put it on network, I cannot take it out. This has nothing to do with NFS. I guess it is an inherent problem with 100BT card itself. I applied most recent recommended patches but no use.

I do the following remedy if I have to take the network out.

1. Take the cable out.
2. Before putting it back in, change the setting of your lancard to AUTO_ON

lanadmin -X AUTO_ON nmid
3. Set your Switch to AUTO_ON
4. Connect the cable. This shouldn't hang
5. set the speed to 100FD
lanadmn -X 100FD nmid
6. Set your switch to 100FD.

This should work. I am not seeing this behaviour with GSC cards though.

-Sri
You may be disappointed if you fail, but you are doomed if you don't try
PVNV  PRASAD
Occasional Contributor

Re: Server hangs if i remove and reconnect the N/W cable.

Hi Sridhar,

if i give "lanadmin -X AUTO_ON 4", it says option is not supported for this Hardware.
As u said Its not a prob with NFS. Today i hv just restarted the server in Single user mode and checked the problem. Even in this level also problem occurs. Differences between this server and others are this one is loaded with JUN'01 HW-CR patches and is K460 whereas the other no problem mac is K250 with base OS. Both servers are connected to add on HP-PB 100base TX cards only.
Sridhar Bhaskarla
Honored Contributor

Re: Server hangs if i remove and reconnect the N/W cable.

I really wonder if you are doing lanadmin for the correct lancard. Can you please attach your lanscan output?.

-Sri
You may be disappointed if you fail, but you are doomed if you don't try
PVNV  PRASAD
Occasional Contributor

Re: Server hangs if i remove and reconnect the N/W cable.

here is lanscan o/p. lan1 is the active i/f.
Sridhar Bhaskarla
Honored Contributor

Re: Server hangs if i remove and reconnect the N/W cable.

Major Number 75 maps to btlan4 and the lanadmin command should work for this driver. Do you have all the patches installed?
I don't remember the patches. I think PHNE_21373 not sure. You may want to search the patch site with btlan4+lanadmin command and find the latest patches. Otherwise lanadmin should work.

-Sri
You may be disappointed if you fail, but you are doomed if you don't try