Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Something is making my server go crazy. First it was just the network had some bad latency, then I noticed it was on the server, not the network. I thought it to be HDD related but I am not sure. It seems to spike every few seconds for less than a second. I shutdown Hmail and Apache, neither were the issue.

A link to 2 images, one of the CPU graph and one of the Process list sorted by CPU time. Also in there are a couple text files with Ping from anotehr machine and a netstat -a -b .

enter image description here enter image description here

Reply from bytes=32 time<1ms TTL=128
Reply from bytes=32 time=2898ms TTL=128
Reply from bytes=32 time<1ms TTL=128
Reply from bytes=32 time<1ms TTL=128
Reply from bytes=32 time=2026ms TTL=128
Reply from bytes=32 time<1ms TTL=128
Reply from bytes=32 time<1ms TTL=128
Reply from bytes=32 time=2022ms TTL=128
Reply from bytes=32 time=2ms TTL=128

Win Server 2003 SP2
Dell PowerEdge sc1425
Xeon 3.4GHZ (Dual Core)
2GB Ram
RAID 1 (mirror )with 2x 1TB Hard Drives

Used mainly as a file server and Active directory and DNS server. Also runs Apache (very light load) and HMailServer for email.

It rarely has load issues. The RAID controller shows the raid (and each drive) as Optimal.

Any Suggestions where to go from here?

Solution: I have 4 external drive bays hooked up to a pci-x raid controller. One of these bays took a crap and was generating a ton of interrupts. Turned it off and voila. I found out it was the interrupts by using process explorer.

share|improve this question
up vote 2 down vote accepted

Take a swing at it with process explorer:

See if you can see a process spiking periodically. Are you pinging the host from the same network, or from remote (like over a vpn?).

share|improve this answer
I have been looking for that tool, Thank you very much for pointing me to it! =) – Andrew May 24 '11 at 20:18
Oops. Hit enter prematurely. Ok so it is interrupts going crazy. Bad processor? Anyone have an idea of what could cause this? – Andrew May 24 '11 at 20:34
Possible causes are driver issues (when DPCs just take too much time) or excessive numbers of interrupts due to some defective or badly designed hardware (mostly expansion cards) - maybe even the NIC. What are the numbers for "context switch delta", "interrupt delta" and "DPC delta" in the CPU statistics of the system information window (call it up through the menu View -> System Information)? – the-wabbit May 24 '11 at 21:36
Context Switch Delta: 3466 – Andrew May 24 '11 at 22:04
Context Switch Delta: 1540-3466 Interrupt Delta: 500 - 1150 DPC Delta: 58-308 – Andrew May 24 '11 at 22:06

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.