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I've been testing some software in a server virtual environment and I've noticed I get a huge amount of CPU usage on the Interrupts process.

My question is, how does this relate to the virtual hardware platform as the rate is allot lower in a real system. Some how the hypervizor scheduler works hard to over come this problem but not as well as on real hardware does.

Obvious things are high I/O and disk access but this application mostly just sits and works in memory allot.

If anyone has experienced the same, please let me know. thanks in advance

Screenshot: Process Explorer alt text

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Can you give us some more information on the underlying hardware and VM config - type of CPU\Amount of Memory in particular. Any other VM's on this vSphere host. Memory overcommit\paging will trigger interrupts, although seeing this sort of load inside the VM strikes me as odd. And can you clarify if you have VMWare tools installed? – Helvick Jul 22 '09 at 14:45
Ok, will start-up the team of vm's on the hosts and get all the details, just to note, when I installed the same application and configuration in Win2k8 the Interrupt usage was considerably less! and my thinking was the 2008 kernal is more native to the hypervizor. I think this is odd and my guess it's down to poor programming of the application. – Darragh Jul 22 '09 at 16:32
vmware has several papers on performance in VMs -,96+124+89 – warren Sep 22 '09 at 8:44
Can you run esxtop on the console for a bit and let us know what values on the default screen for that server are? Of particular interest is the %RDY stat. Also how many CPU's to do you have allocated to the machine? – Zypher Nov 6 '09 at 1:22
as you noticed 2008 is much friendlier to virtual environments as it has kernel enlightenments. 2003 only has driver enlightenment available. – Jim B Mar 15 '10 at 10:29
up vote 1 down vote accepted

Have you read the VM's CPU usage from the guest or the host? Guest CPU usage figures are inherently wrong.

Other than that make sure you've removed any unnecessary virtual hardware like floppies/serial ports etc. and make sure you're on the latest vmtools.

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This VM wasn't created through a P2V migration by any chance? If so make sure that the latest VMware tools are installed and that there are no drivers left from the physical hardware or software related to the hardware such as management agents.

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In my years of working at home with W2003 server, Enterprise mostly, i found out that the hard part is to find answers, problems are there where you don't expect them. In this case i had msmpeng.exe shooting in the 100% during transfer files to the server and now it is interrupts when i want to read from the server. This hardware is an old Compaq EN series pc with P4 1.00ghz with 4 GB memory. As a SATA harddisk solution i use a pci, 3 ports raid-3 XFX-card. In this machine, and with this same config, i had a single disk as the C-disk, until there was a bad spot on this 10 year old datacarrier. I had to reformat it, (IDE) and bought a second HD and mirrored it for sure. I started to install W2003 server on it, i downloaded SP1, SP2 and installed it on the server, Then i updated everything, and in the end i gained acces to the RAID-3 disk, i made sure the server admin had all the rights. Well, since this problem i read here on this board, i had it before, but it is so unpredictable wether it is the disk where the system resides, or the data (raid), or is it the old hardware, or the network? In this way i can't really tell. Until i have the money to buy a good datastorage for my medialibrary, i'll keep trying to find the cause. I have a similar pc, and i think i'm going to testrun this pc and elevate it to server, see if the problem reoccurs. I'm sorry that i can't give you a straight answer, even Microsoft can't give it, there are so much factors. I say, try to reinstall a fresh server on a replacement harddisk in the same configuration, maybe that'll help.

Ps. currently copying a 6,5 GB file from server to pc, well, a 11Mbit wireless connection is faster!

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Is there an answer in here? – Andrew Schulman Jan 12 '14 at 15:10

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