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mbonsack
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Workstation 7 on Ubuntu 9.10 host -- VMs run dog slow

I know there's another post on this topic but for the life of me I can't find it. I'm having the same problem -- running VMs cause the CPU to spike to 100% and they all run dog slow. Others report good success with Karmic. Any hints?

Thanks, -mark

The thread I was referring to is in the locked beta forum: http://communities.vmware.com/thread/238765

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admin
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There seem to be Linux kernel scheduler changes between the 2.6.28 kernel (used by Ubuntu 9.04) and the 2.6.31 kernel (used by Ubuntu 9.10) that interact poorly with SMP VMs. We are investigating this; sorry I don't have anything more conclusive to tell you.

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mbonsack
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The gentleman who posted the first thread suggested I set my VMs to only use 1 core. That worked, but I know 2 cores worked in my 9.04 installation. Could those of you running WS 7 on Ubuntu 9.10 try running with more than one core and see if you run into this problem?

Thanks! -mark

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There seem to be Linux kernel scheduler changes between the 2.6.28 kernel (used by Ubuntu 9.04) and the 2.6.31 kernel (used by Ubuntu 9.10) that interact poorly with SMP VMs. We are investigating this; sorry I don't have anything more conclusive to tell you.

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mbonsack
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Thanks for this; at this point confirmation of the problem by VMware is OK for me. While investigating this issue I ran across several threads that mention it is best practice to allocate VMs to use at most 1 less core than you have in your machine. So, on my dual-core laptop I should limit my VMs to use only 1 core. Is this still sound advice?

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admin
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Best practice is indeed not to overcommit host CPUs, in Workstation, so yeah, you should have more than 2 physical cores to run a 2-vcpu guest.

However, as you've noticed, 2 vcpus on 2 pcpus worked better under Ubuntu 9.04 and we're investigating why it got worse.

mbonsack
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What will be the method by which I'll know about your progress? Will

you update the thread directly, or otherwise file an SR on my (and/or

others') behalf?

Thanks! -mark

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hmunster
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Hi, I am also facing the same issue but with an XP Pro guest that was working fine under Jaunty. Even with only one cpu enabled the vm is almost unusable with the cpu continually at 100%. Need a fix soon or it's back to 9.04 for me Smiley Happy

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mbonsack
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Is your host machine a single-CPU box? Maybe 9.10 has issues when the number of pCPU==vCPU. On my dual-core laptop single-vCPU VMs work fine, and the VMs range from 32-bit XP pro to 64-bit Fedora 10.

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admin
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Mark, filing an SR couldn't hurt -- while hopefullly we'll update the thread with good news at some point, if that good news comes in the form of a new revision of Workstation we wouldn't be able to announce it until it's already public knowledge. Sorry, that's just company policy on unannounced products.

It's also possible good news comes in the form of Linux kernel updates. I'm not trying to cast the blame over there, but the Linux kernel community has recently been discussing changes in scheduler behavior noticed in 2.6.31 and maybe they'll decide to make changes that benefit us.

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mbonsack
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Regarding an SR (which I can't file because I'm just evaluating) -- it sounds like you guys have a handle on this and to the extent this new scheduler will appear in all distros shortly, I would think there would be movement on one or both sides for a timely fix. To that end, have you noticed this problem on other newer distros?

Thanks for your help.

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admin
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I don't think any other distro has shipped a 2.6.31 kernel yet, though Fedora 12 is about to, and I'd expect to see the same issue there.

At the risk of stating the obvious, none of these brand-new (or future) distro releases are currently qualified as supported host OSes for Workstation, though of course we know people want them and we're working on it.

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admin
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Random thought.

Ubuntu 9.10 ships with ext4 as default filesystem whereas Ubuntu 9.04 uses ext3 by default. Can anyone try using ext4 with Ubuntu 9.04 and let us know if the VMs still run slow with vcpu == pcpu?

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admin
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We know it's not the filesystem. (We've tried Ubuntu 9.04 with ext4, and we've tried various 2.6.31 kernels with ext3.)

And we don't actually know that the performance problem is when pcpu==vcpu -- the variant I'm familiar with is with 2 vcpus on a 2 pcpu host, and we have one data point here that 1 vcpu VM was also slow (but we don't yet know that was a 1 pcpu host, and it could be an unrelated problem), but let's not assume that's the explanation.

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mbonsack
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Could it be/have you looked at this?

https://bugs.launchpad.net/ubuntu/+bug/459628

-mark

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hmunster
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It's a dual core laptop. Although I may have to revise my symptoms as it appears that another XP guest works fine with 1 vCPU but not with 2 vCPU. My initial report was from working with my main XP guest which I use for work (with 2 x 20GB harddrives) which is almost unusable with either 1 or 2 vCPU's enabled.

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mbonsack
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What are your thoughts as to why your first XP guest works poorly with either 1 or 2 vCPUs? What might be different about it than the second one which works fine with 1 vCPU?

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hmunster
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The only real difference I can see is that the problem XP Pro SP3 guest has two 2 x 20GB persistent harddrives (the second was added at a later date) which I use for work and has many applications installed, as opposed to the other which is a relatively clean build of XP Pro SP3 with a 15GB 'growable' harddrive.

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mbonsack
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When I see this problem, it manifests itself right after POST -- when the initial, "Windows XP" logo against a a black screen is loading, with the progress bar scrolling from left to right at the bottom. There is no way at that point that anything about the apps on the machine is known by the Windows kernel. By any chance, is the "number of processors" or "number of cores" still set to 2 in your VM (I know that's a stretch)? Otherwise, can you temporarily change how your drives are attached -- maybe not attach both, etc. just to see if the thing will boot with decent performance? How does the memory compare on each of your XP guests?

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d_black
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I'd just like to add that I also have a big problem with a Ubuntu 9.10 64bit host and slow VMs (all 32bit XP SP3). The system monitor applet shows one CPU maxxing out when I am active in the VM, even just moving the mouse.

It does, however, go away or is much reduced at least on the VMs I've tried so far when I drop back to 1 CPU. I am running a dual-core laptop (Dell M6300) and I was running VMs with 2 CPUs flawlessly in 8.04 32bit host. The workloads in the 32bit XP SP3 VMs operate somewhat better with 2 CPUs, so I'd like to get back to that as soon as possible. Smiley Happy

I filed a support request before noticing 9.10 was in the unsupported list. That's fine for a short while, if slightly annoying... however I'd strongly (but hopefully politely) request that you make every effort to meet Ubuntu 10.04 LTS when it hits the street. Long-term-support releases are much more important than these other ones. I was just personally getting too far behind at 8.04 LTS. A LTS release probably will be a relatively minor set of changes for stability, so you probably won't have a problem anyway.

If you'd like me to try anything I'd be happy to help.

Darron

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kingneutron
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I completely agree with you on the importance of LTS revs. My main Workstation box is Xubuntu 8.0464; will probably have to wait ~6 months after 10.04 comes out to upgrade, so Vmware can catch up. It would be nice if Vmware supported 10.04 as Host right when it comes out tho...

./. If you have appreciated my response, please remember to apply Helpful/Correct points. TIA

./. If you have appreciated my response, please remember to apply Helpful/Correct points. TIA
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