Kernel parameter change

[Bruno Cunha]

Hi all, one simple question, if I change some kernel parameters like semmni,semmnu,msgmap,msgmnb,msgseg,msgtql this can cause machine problems at the network level ?

Thanks

[Mark Greene_1]

They could indirectly create network problems if any of the changes affected the software applications so that they run slower.

What sort of network problems are you seeing? If you do a "netstat -a", are you seeing very high numbers (over 100) in any of the error counters?

What does "vmstat 2 10" tell you? Are you seeing high I/O wait or zero idle time that may appear to your users as slow network response when in fact it is slow system response?

HTH
mark

[PIYUSH D. PATEL]

Hi Bruno,

Changing these memory parameters will not affect the network paramters and create problems at network level.

What network level problems are you referring to ??

Piyush

[Bruno Cunha]

Hi, I'm getting
vmunix: btlan6: NOTE: MII Link Status Not OK - Check Cable Connection to Hub/Switch at 6/0/0....
vmunix: btlan6: NOTE: MII Link Status Not OK - Check Cable Connection to Hub/Switch at 7/0/0....

Thanks

[Mark Greene_1]

This is a configuration conflict between the NIC and the switch. Turn autonegotiation off on the NIC and on the switch. Set both to 100Mbps, fixed , full duplex.

HTH
mark

[T G Manikandan · Accepted solution]

Just check whether there is a speed mismatch between the switch/hub and the server.
Just use lanamdin

then choose
lan
then choose
display

check the speed.
Might be oen is 100Mbps and the other is 10Mbps.

Thanks
G Manikandan

[Bruno Cunha]

But why this is occuring now? before the parameters change it was ok (or some coicidence???)

[Mark Greene_1]

did you reboot after making the changes? (The reboot is what would have done it, not the changes.)

mark

[Bruno Cunha]

Yes, a reboot was made after the parameters change.

[Roger Baptiste]

hi,

I don't think the kernel parm change has any relation to the messages seen. Check the lan connection of btlan6 ; do a lanscan and find which H/W path btlan6 is on and then do a physical check of the cable/switch.

HTh
raj

[Sanjay_6]

Hi Bruno,

Looks like either the switch port setting or the lan card setting have got changes in the process of the reboot. The kernel parameter change will not normally lead to this sort of network error message.

Hope this helps.

regds

[PIYUSH D. PATEL]

Hi Bruno,

It is definitely a network level problem..

check for the speed settings of the switch and lan card.

Piyush

[MANOJ SRIVASTAVA]

Hi Bruno


Can you do a netstat -nr and post the o/p . Or atelast ping at the gateway .



Manoj Srivastava

[Michael Tully]

Hi,

As the other guys have indicated, there is no
relationship between those kernel parameters
and network activity. As your message indicates
there could be a network problem at your switch
the NIC card itself or the cable.

Use the statistical information that is
provided in 'lanadmin' to assist you.
Usually slow responses and duplex mis-matches
will show up here. The 'Late collisions'
entry is the one I generally use for this.

Set the auto-negotiate to off, and generally
full-duplex is used. You can change this on
the fly.

# lanadmin -X 100FD 0 (NIC card No.)

You then still need to update the appropriate
network config file that applies to your system.
/etc/rc.config.d/hp.......

HTH
~Michael~

[U.SivaKumar_2]

hi,
The kernel parameters you have indicated are related to IPC InterProcess Communications viz.
semaphores and messages.
I find no reason to blame these kernel parameters change as the cause of that error
message.

regards,
U.SivaKumar