mystereman
Enthusiast
Enthusiast

ESX 4 requires VT?

So, I downloaded the eval of vSphere 4 and decided to try it out on one of my older servers, an Intel SE7520BD2 based server with dual Xeon's with EM64T.

The install seemed to go fine. I wiped my old 3.02 install and everything seemed to boot up a lot smoother until I get to the main screen, which says "461: The Execute Disable/No Execute CPU feature is not enabled for this machine", which I take to mean VT is not enabled. I did some research, and even though the CPU has VT, the motherboard does not support it (even with latest bios).

So when I try to fire up the vSphere client to log in, i get a message about "clients.xml" file parsing error, and "The type initializer for 'VirtualInfrastructure.Utils.HttpWebRequestProxy' threw an exception."

When I try to login via the web interface, I get "Service Unavailable".

So am I out of luck here? I don't have an extra newer machine laying around right now to play around with this. Is there any hidden setting that allows it to run without VT?

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EDV-COMPAS
Enthusiast
Enthusiast

generaly, VT is not required for esx4, but i think to remeber that intel xeon cpu´s need VT enabled to support 36bit adressing, which is required for 64bit support on intel xeon cpu´s.

but if the esx4 system boots up, it should be possible to connect with the vsphere to it.

web access is disabled by default, so this message is normal.

to enable web access, take a look to this thread: http://communities.vmware.com/message/1273768#1273768

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mystereman
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Enthusiast

Well, it looks like my connection problem was related to running the client on Windows 7. There is a workaround here:

http://communities.vmware.com/thread/211440

I'm going to see if i can run 32 bit hosts on this.

EDIT:

Indeed, I can start 32 bit VM's just fine on this server. Lots of interesting error messages in the logs, wish I could get rid of those.

While I can start and run 32 bit VM's on this computer, performance seems to be VERY slow and unstable. For instance, I installed a Vista SP2 image, and it was unable to complete some of the Windows Updates and kept rolling back (particularly IE8). I installed a copy of the Windows 7 beta, and that seems more stable but still very slow. For instance, installing Office takes more than an hour.

So it seems like VT is pretty much necesary to get any kind of performance.

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agesen
VMware Employee
VMware Employee

While I can start and run 32 bit VM's on this computer, performance

seems to be VERY slow...

So it seems like VT is pretty much necesary to get any kind of

performance.

That's probably overstating things a bit. Or rather, something

else than absence of VT must be the explanation...

Past versions of ESX did not use VT for running 32 bit guests

(instead they used binary translation). With ESX 4.0, we gained the

ability to run 32 bit guests with VT, but also retained the ability

to use binary translation. In your case, on a CPU that doesn't have

VT, we will fall back to binary translation.

Our expectation is that Vista SP2 should perform no worse on ESX 4.0

on a CPU without VT than it did on previous versions of ESX (which

didn't "want" to use VT to run this guest).

That said, you probably have an Intel Pentium 4 CPU from ~2005. Modern

CPUs are certainly a lot more powerful, so if you try this setup on a

different host, you will hopefully see a very nice perforamnce boost.

VT or not... And you can in fact try it both ways and compare, if you

like.

Best regards,

Ole

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mystereman
Enthusiast
Enthusiast

This is a 2 Processor Single core Xeon system runninga t 3Ghz with 6GB of DDR 266 memory. No, certainly not as fast as my dual quad core Xenon servers with DDR2, but it's no slouch.

I had originally configured the BIOS to use pre-fetch, but for some reason that caused the error logs to fill with spurious thermal warnings about pcpu 0. Disabling the prefetch made them go away. I'm using the latest 9.0 bios (form 2006 I think). The CPU has EM64T, and the console says it's running on a X64 processor. Is there perhaps an incompatibility between a 64 bit host and not having VT? If this were a 32 bit HOST would it perform better? Is there any way to tell ESX4 to use only 32 bit components?

I have allocated 3GB of RAM to Windows 7, and given it 1 processor. It should be plenty fast in this configuration.

Other things to be aware of. The host is using an Intel Megaraid SCSI RAID controller with 10K RPM SCSI drives (3 drives in a RAID 5 array). This is running locally (no SAN). I have no other Virtual Machines on the system. This is the only thing running (i'm just doing it for testing purposes). Any suggestions?

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agesen
VMware Employee
VMware Employee

Is there perhaps an incompatibility between a 64 bit host and not

having VT?

No. Although I would note that Intel shipped very few CPUs that

had EM64T but no VT (back in the vaning days of Pentium 4, Prescott).

If this were a 32 bit HOST would it perform better?

No, it wouldn't be able to run vSphere 4.0 at all because we use

a 64 bit vmkernel.

Is there any way to tell ESX4 to use only 32 bit components?

No. But, honestly, this would be unlikely to help anyway. When you

run a 32 bit guest on top of ESX 4, the physical CPU will be in

32 bit "legacy mode" most of the time. In effect, you already get

what you are asking for.

Unfortunately, while I know (too) much about CPUs, I'm no storage

expert so I cannot comment on your SCSI setup.

Thanks,

Ole

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mystereman
Enthusiast
Enthusiast

The CPU has VT i'm pretty sure, but the motherboard doesn't support it.

My pont about the SCSI setup was that it's fast and local, so that should not slow anything down.

I enabled VMI Paravirtualization also.. is that bad? I've had it both on and off... seems a little faster with it on.

I have CPU/MMU Virtualization to Automatic. I've also tried with Software MMU.

When the OS boots, I can watch the VM freeze.. or rather, i can watch the boot animations freeze, and the pointer animations freeze.. all for like a second at a time.

I don't know. This machine ran 3.02 wonderfully. Maybe i'll just back it down to 3.5.

UPDATE:

Now the VM is freezing constantly. I reboot, and it freezes about 5 minutes in.. so Windows 7 isn't really any more stable in this situation that Vista was. So, I think i'm going to back off to 3.5.

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agesen
VMware Employee
VMware Employee

The CPU has VT i'm pretty sure, but the motherboard doesn't support it.

You may want to check the BIOS settings and/or try to get a BIOS upgrade.

But, again, this doesn't explain it. You state ESX 3.x was fine. 4.0 can

run VMs in exactly the same manner (with binary translation) and we expect

with the same performance.

I enabled VMI Paravirtualization also.. is that bad?

No, but: it's a no-op for all but a small set of 32 bit Linux versions.

I don't know. This machine ran 3.02 wonderfully. Maybe i'll just back it

down to 3.5.

Or you could file a support request and have our support people look

into the case in more detail.

Best of luck, and sorry that I couldn't help, other than provide feedback

on your various hypotheses.

Thanks,

Ole

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mystereman
Enthusiast
Enthusiast

No, the motherboard does not support VT. This is direct from Intel. I have the latest bios (from 2006). There is no setting to Enable or Disable VT.

As for a support request. I am simply using the demo version at this point, so I don't have a support contract. Haven't made the upgrade to 4.0 yet license wise.

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Greggo
Contributor
Contributor

Interesting comment, 'Our expectation is that Vista SP2 will perform no worse...'

Vista SP1 does not perform well at all and so far, SP2 seems to be much worse using RDC. Removing the service pack will restore very reasonable performance.

ESXi 4.0 with latest updates

Dual quad core 2.66

8GB RAM

Very fast I/O

Single VM running Windows Vista 32-bit for testing purposes.

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