A Tail of Different VM Performance 1

Posted by JD 06/05/2016 at 16:00

Below are some statistics from a few running VMs for your consideration.

ID S RDRQ WRRQ RXBY TXBY %CPU %MEM    TIME   NAME                            
 4 R    0    0  287    0 26.0  9.0 454:26.51 win7ult
 2 R    0    3 551K  16K  3.3 19.0 258:56.21 desktop
 5 R    0    3  287    0  0.7 15.0 217:59.98 email
 6 R    0    0  287    0  0.1  3.0  10:24.97 email-front
 3 R    0    2  287    0  0.1  7.0  43:37.56 blog

Breakdown of the Stats

I watched the virt-top output for about 2 minutes and grabbed those numbers above during a representative 2 sec period. The Windows VM never dropped below 25% use. The other VMs each would bounce up as something required it, then would drop back down to nearly nothing when done.

More details below.

Workloads

  • Windows7 Ultimate desktop. At the time, it wasn´t doing anything. Not even a userid logged in.
  • desktop is an Ubuntu Server 14.04 running OpenBox as a WM. Minimal GUI, since it is only used through remote destop (x2go) and ssh. This is my primary desktop system and usually runs 15+ GUI programs (mostly xterms) 24/7/365, so it has more RAM allocated.
  • email is an Ubuntu Server 14.04 running Zimbra. No GUI. Zimbra is a MS-Exchange replacement and then some more , but it is also a hog when compared to other Unix email systems.
  • email-front is a tiny debian VM, no GUI. It does email rejection, block lists, spam filtering, anti-virus scanning/rejection. Basically, it marks email as Good or Bad and rejects anything terrible, This machine is constantly patched and maintained, but tiny.
  • blog is an Ubuntu Server 14.04, no GUI. This blog runs on it. It is also the primary reverse proxy server for the entire network and hosts about 20 other, small, websites for specific purposes. There are some RoR sites, so it needs more RAM than I´d normally allocate to a small, webhosting system.

What´s Up with Windows?

All I know is that it sucks 25%-130% of the available CPU, never less. When the CPU use goes above 50% for this VM, it makes sense. It is a TV recording machine. What is it doing the rest of the time? Nothing useful to me. This is an almost stock Win7 install. There are only a few non-Microsoft programs installed.

  • Quicken
  • TaxCut
  • TeraCopy
  • KeePassX
  • Firefox
  • Notepad++
    Everything else is stock, Microsoft.

Remoted into the Win7 VM and used the Task Manager to see what it is doing.

  • 50% CPU.
  • 600MB RAM used.
  • RDP clip is the top process.

Need more details, but Performance Monitor has too much info that needs to be heavily filtered.

  1. JD 06/24/2016 at 21:45

    Should point out that all the VMs, including Windows, are using virtio drivers for both disk and networking. This isn’t an unfair comparison based on IO stuff.

    Grabbed some more stats just now. Win7 doesn’t look too bad today. Still higher than the others, but not excessively so, IMHO.

       ID S RDRQ WRRQ RXBY TXBY %CPU %MEM    TIME   NAME                                         
    4 R    0    0  489    0  8.7  9.0  74:43:48 Win7Ult
    5 R    0    2 2237 4369  3.8 19.0  20:50:03 desktop
    6 R    0   27  489    0  1.0 15.0  22:22:36 email
    2 R    0    0  489    0  0.2  3.0  59:51.40 email-front
    3 R    0    0  597   54  0.1  7.0 255:04.20 blog

    And logging in over RDP seems to be the issue with the CPU AFTER I connected. There’s a patch for it from 2012, which was installed here. Guess it came back. That doesn’t explain the high CPU before any RDP connection was made in the data above.