I suppose the typical questions need to be asked here:
- What are the specs of the hardware Red Hat is running on?
Ex. Dell R710 16-way w/ 16GB RAM, RAID 5 on Cheetahs (15kRPM), etc.
system was working fine until last week
What was the last change made to the system before you started experiencing these symptoms? Something must have changed. Anything from a yum update to a hardware change, e.g. swapping hard drives, upgrading RAM, etc.
What else is top showing you besides that particular bash process?
What is the output of free -m ?
What is the output of cat /proc/interrupts?
Have you installed the sar utils? If so, what are their outputs?
Look at your typical iostat, vmstat and relevant performance monitoring utilities. Anything out of the ordinary?
Disk space full? You can check it with df -h. Verify which directories are using how much disk space with du -sh /* from top level. Then, traverse into each applicable directory by using du -sh /etc/* then du -sh /etc/httpd/* and so forth.
Verify your processes by using ps aux and ps -elf
Use lsof to view open files. man lsof has lots of useful information on proper usage.
Have you checked for DDOS attacks? Perhaps something is hitting your server hard with packets. Check this with the typical tools, i.e. netstat, tcpdump, snort, etc.