Apologies for not sending this info out earlier, but I did find the problem. It actually had nothing to do with the system itself. We had a some distribution switches that were causing spanning tree recalcs which drove up the CPU on our core switches. The CPU spikes caused some queue drops on the core switch interfaces of some devices. It was the dropped packets that then caused the system to appear to be lagging.
Resolving those along with some hardware upgrades at the core helped resolved the switch interface queue drops and the appearance of system lag. Thanks again for all the tips! Mike On Wed, Feb 15, 2012 at 10:49 AM, Dean, Mike <[email protected]> wrote: > Hello all, hoping you can help. We have a RedHat box that two days ago > starting having periods of slow performance. The slow down is bad enough > that you can see it when trying to type at a terminal and some processes, > such as SNMP, don't respond. Users have also been disconnected. > > The last change that was made was applying the normal monthly patches on > 2/7 (the problem only started showing up yesterday). According to the > information from 'top', the system seems to be fine. A typical snapshot > looks like this: > > Tasks: 282 total, 8 running, 274 sleeping, 0 stopped, 0 zombie > Cpu(s): 1.1%us, 0.3%sy, 0.0%ni, 98.5%id, 0.0%wa, 0.0%hi, 0.0%si, > 0.0%st > Mem: 3909268k total, 1669580k used, 2239688k free, 231832k buffers > Swap: 6094840k total, 0k used, 6094840k free, 972756k cached > > Any ideas on where to look? > > Thanks! > > Mike > >
